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linux/drivers/media/cec/core/cec-pin.c

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media: cec: add SPDX license info Replace the old license information with the corresponding SPDX license. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-02-07 22:34:03 +08:00
// SPDX-License-Identifier: GPL-2.0-only
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
/*
* Copyright 2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
*/
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/sched/types.h>
#include <media/cec-pin.h>
media: cec-pin.h: move non-kAPI parts into cec-pin-priv.h The kAPI cec-pin.h header also defined data structures that did not belong here but were private to the CEC core code. Split that part off into a cec-pin-priv.h header. Signed-off-by: Hans Verkuil <hansverk@cisco.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2017-10-14 00:01:32 +08:00
#include "cec-pin-priv.h"
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
/* All timings are in microseconds */
/* start bit timings */
#define CEC_TIM_START_BIT_LOW 3700
#define CEC_TIM_START_BIT_LOW_MIN 3500
#define CEC_TIM_START_BIT_LOW_MAX 3900
#define CEC_TIM_START_BIT_TOTAL 4500
#define CEC_TIM_START_BIT_TOTAL_MIN 4300
#define CEC_TIM_START_BIT_TOTAL_MAX 4700
/* data bit timings */
#define CEC_TIM_DATA_BIT_0_LOW 1500
#define CEC_TIM_DATA_BIT_0_LOW_MIN 1300
#define CEC_TIM_DATA_BIT_0_LOW_MAX 1700
#define CEC_TIM_DATA_BIT_1_LOW 600
#define CEC_TIM_DATA_BIT_1_LOW_MIN 400
#define CEC_TIM_DATA_BIT_1_LOW_MAX 800
#define CEC_TIM_DATA_BIT_TOTAL 2400
#define CEC_TIM_DATA_BIT_TOTAL_MIN 2050
#define CEC_TIM_DATA_BIT_TOTAL_MAX 2750
/* earliest safe time to sample the bit state */
#define CEC_TIM_DATA_BIT_SAMPLE 850
/* earliest time the bit is back to 1 (T7 + 50) */
#define CEC_TIM_DATA_BIT_HIGH 1750
/* when idle, sample once per millisecond */
#define CEC_TIM_IDLE_SAMPLE 1000
/* when processing the start bit, sample twice per millisecond */
#define CEC_TIM_START_BIT_SAMPLE 500
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
/* when polling for a state change, sample once every 50 microseconds */
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
#define CEC_TIM_SAMPLE 50
#define CEC_TIM_LOW_DRIVE_ERROR (1.5 * CEC_TIM_DATA_BIT_TOTAL)
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
/*
* Total data bit time that is too short/long for a valid bit,
* used for error injection.
*/
#define CEC_TIM_DATA_BIT_TOTAL_SHORT 1800
#define CEC_TIM_DATA_BIT_TOTAL_LONG 2900
/*
* Total start bit time that is too short/long for a valid bit,
* used for error injection.
*/
#define CEC_TIM_START_BIT_TOTAL_SHORT 4100
#define CEC_TIM_START_BIT_TOTAL_LONG 5000
/* Data bits are 0-7, EOM is bit 8 and ACK is bit 9 */
#define EOM_BIT 8
#define ACK_BIT 9
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
struct cec_state {
const char * const name;
unsigned int usecs;
};
static const struct cec_state states[CEC_PIN_STATES] = {
{ "Off", 0 },
{ "Idle", CEC_TIM_IDLE_SAMPLE },
{ "Tx Wait", CEC_TIM_SAMPLE },
{ "Tx Wait for High", CEC_TIM_IDLE_SAMPLE },
{ "Tx Start Bit Low", CEC_TIM_START_BIT_LOW },
{ "Tx Start Bit High", CEC_TIM_START_BIT_TOTAL - CEC_TIM_START_BIT_LOW },
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
{ "Tx Start Bit High Short", CEC_TIM_START_BIT_TOTAL_SHORT - CEC_TIM_START_BIT_LOW },
{ "Tx Start Bit High Long", CEC_TIM_START_BIT_TOTAL_LONG - CEC_TIM_START_BIT_LOW },
{ "Tx Start Bit Low Custom", 0 },
{ "Tx Start Bit High Custom", 0 },
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
{ "Tx Data 0 Low", CEC_TIM_DATA_BIT_0_LOW },
{ "Tx Data 0 High", CEC_TIM_DATA_BIT_TOTAL - CEC_TIM_DATA_BIT_0_LOW },
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
{ "Tx Data 0 High Short", CEC_TIM_DATA_BIT_TOTAL_SHORT - CEC_TIM_DATA_BIT_0_LOW },
{ "Tx Data 0 High Long", CEC_TIM_DATA_BIT_TOTAL_LONG - CEC_TIM_DATA_BIT_0_LOW },
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
{ "Tx Data 1 Low", CEC_TIM_DATA_BIT_1_LOW },
{ "Tx Data 1 High", CEC_TIM_DATA_BIT_TOTAL - CEC_TIM_DATA_BIT_1_LOW },
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
{ "Tx Data 1 High Short", CEC_TIM_DATA_BIT_TOTAL_SHORT - CEC_TIM_DATA_BIT_1_LOW },
{ "Tx Data 1 High Long", CEC_TIM_DATA_BIT_TOTAL_LONG - CEC_TIM_DATA_BIT_1_LOW },
{ "Tx Data 1 High Pre Sample", CEC_TIM_DATA_BIT_SAMPLE - CEC_TIM_DATA_BIT_1_LOW },
{ "Tx Data 1 High Post Sample", CEC_TIM_DATA_BIT_TOTAL - CEC_TIM_DATA_BIT_SAMPLE },
{ "Tx Data 1 High Post Sample Short", CEC_TIM_DATA_BIT_TOTAL_SHORT - CEC_TIM_DATA_BIT_SAMPLE },
{ "Tx Data 1 High Post Sample Long", CEC_TIM_DATA_BIT_TOTAL_LONG - CEC_TIM_DATA_BIT_SAMPLE },
{ "Tx Data Bit Low Custom", 0 },
{ "Tx Data Bit High Custom", 0 },
{ "Tx Pulse Low Custom", 0 },
{ "Tx Pulse High Custom", 0 },
{ "Tx Low Drive", CEC_TIM_LOW_DRIVE_ERROR },
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
{ "Rx Start Bit Low", CEC_TIM_SAMPLE },
{ "Rx Start Bit High", CEC_TIM_SAMPLE },
{ "Rx Data Sample", CEC_TIM_DATA_BIT_SAMPLE },
{ "Rx Data Post Sample", CEC_TIM_DATA_BIT_HIGH - CEC_TIM_DATA_BIT_SAMPLE },
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
{ "Rx Data Wait for Low", CEC_TIM_SAMPLE },
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
{ "Rx Ack Low", CEC_TIM_DATA_BIT_0_LOW },
{ "Rx Ack Low Post", CEC_TIM_DATA_BIT_HIGH - CEC_TIM_DATA_BIT_0_LOW },
{ "Rx Ack High Post", CEC_TIM_DATA_BIT_HIGH },
{ "Rx Ack Finish", CEC_TIM_DATA_BIT_TOTAL_MIN - CEC_TIM_DATA_BIT_HIGH },
{ "Rx Low Drive", CEC_TIM_LOW_DRIVE_ERROR },
{ "Rx Irq", 0 },
};
static void cec_pin_update(struct cec_pin *pin, bool v, bool force)
{
media: cec: replace pin->cur_value by adap->cec_pin_is_high The current CEC pin value (0 or 1) was part of the cec_pin struct, but that assumes that CEC pin monitoring can only be used with a driver that uses the low-level CEC pin framework. But hardware that has both a high-level API and can monitor the CEC pin at low-level at the same time does not need to depend on the cec pin framework. To support such devices remove the cur_value field from struct cec_pin and add a cec_pin_is_high field to cec_adapter. This also makes it possible to drop the '#ifdef CONFIG_CEC_PIN' in cec-api.c. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-08-20 18:53:10 +08:00
if (!force && v == pin->adap->cec_pin_is_high)
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
return;
media: cec: replace pin->cur_value by adap->cec_pin_is_high The current CEC pin value (0 or 1) was part of the cec_pin struct, but that assumes that CEC pin monitoring can only be used with a driver that uses the low-level CEC pin framework. But hardware that has both a high-level API and can monitor the CEC pin at low-level at the same time does not need to depend on the cec pin framework. To support such devices remove the cur_value field from struct cec_pin and add a cec_pin_is_high field to cec_adapter. This also makes it possible to drop the '#ifdef CONFIG_CEC_PIN' in cec-api.c. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-08-20 18:53:10 +08:00
pin->adap->cec_pin_is_high = v;
media: cec: improve CEC pin event handling It turns out that the struct cec_fh event buffer size of 64 events (64 for CEC_EVENT_PIN_CEC_LOW and 64 for _HIGH) is too small. It's about 160 ms worth of events and if the Raspberry Pi is busy, then it might take too long for the application to be scheduled so that it can drain the pending events. Increase these buffers to 800 events which is at least 2 seconds worth of events. There is also a FIFO in between the interrupt and the cec-pin thread. The thread passes the events on to the CEC core. It is important that should this FIFO fill up the cec core will be informed that events have been lost so this can be communicated to the user by setting CEC_EVENT_FL_DROPPED_EVENTS. It is very hard to debug CEC problems if events were lost without informing the user of that fact. If events were dropped due to the FIFO filling up, then the debugfs status file will let you know how many events were dropped. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-07 05:20:00 +08:00
if (atomic_read(&pin->work_pin_num_events) < CEC_NUM_PIN_EVENTS) {
u8 ev = v;
if (pin->work_pin_events_dropped) {
pin->work_pin_events_dropped = false;
media: cec: set ev rather than v with CEC_PIN_EVENT_FL_DROPPED bit Setting v with the CEC_PIN_EVENT_FL_DROPPED is incorrect, instead ev should be set with this bit. Fix this. Detected by CoverityScan, CID#1467974 ("Extra high-order bits") Fixes: 6ec1cbf6b125 ("media: cec: improve CEC pin event handling") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Hans Verkuil <hansverk@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-04-18 23:26:19 +08:00
ev |= CEC_PIN_EVENT_FL_DROPPED;
media: cec: improve CEC pin event handling It turns out that the struct cec_fh event buffer size of 64 events (64 for CEC_EVENT_PIN_CEC_LOW and 64 for _HIGH) is too small. It's about 160 ms worth of events and if the Raspberry Pi is busy, then it might take too long for the application to be scheduled so that it can drain the pending events. Increase these buffers to 800 events which is at least 2 seconds worth of events. There is also a FIFO in between the interrupt and the cec-pin thread. The thread passes the events on to the CEC core. It is important that should this FIFO fill up the cec core will be informed that events have been lost so this can be communicated to the user by setting CEC_EVENT_FL_DROPPED_EVENTS. It is very hard to debug CEC problems if events were lost without informing the user of that fact. If events were dropped due to the FIFO filling up, then the debugfs status file will let you know how many events were dropped. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-07 05:20:00 +08:00
}
pin->work_pin_events[pin->work_pin_events_wr] = ev;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->work_pin_ts[pin->work_pin_events_wr] = ktime_get();
pin->work_pin_events_wr =
(pin->work_pin_events_wr + 1) % CEC_NUM_PIN_EVENTS;
media: cec: improve CEC pin event handling It turns out that the struct cec_fh event buffer size of 64 events (64 for CEC_EVENT_PIN_CEC_LOW and 64 for _HIGH) is too small. It's about 160 ms worth of events and if the Raspberry Pi is busy, then it might take too long for the application to be scheduled so that it can drain the pending events. Increase these buffers to 800 events which is at least 2 seconds worth of events. There is also a FIFO in between the interrupt and the cec-pin thread. The thread passes the events on to the CEC core. It is important that should this FIFO fill up the cec core will be informed that events have been lost so this can be communicated to the user by setting CEC_EVENT_FL_DROPPED_EVENTS. It is very hard to debug CEC problems if events were lost without informing the user of that fact. If events were dropped due to the FIFO filling up, then the debugfs status file will let you know how many events were dropped. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-07 05:20:00 +08:00
atomic_inc(&pin->work_pin_num_events);
} else {
pin->work_pin_events_dropped = true;
pin->work_pin_events_dropped_cnt++;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
}
wake_up_interruptible(&pin->kthread_waitq);
}
static bool cec_pin_read(struct cec_pin *pin)
{
bool v = pin->ops->read(pin->adap);
cec_pin_update(pin, v, false);
return v;
}
static void cec_pin_low(struct cec_pin *pin)
{
pin->ops->low(pin->adap);
cec_pin_update(pin, false, false);
}
static bool cec_pin_high(struct cec_pin *pin)
{
pin->ops->high(pin->adap);
return cec_pin_read(pin);
}
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
static bool rx_error_inj(struct cec_pin *pin, unsigned int mode_offset,
int arg_idx, u8 *arg)
{
#ifdef CONFIG_CEC_PIN_ERROR_INJ
u16 cmd = cec_pin_rx_error_inj(pin);
u64 e = pin->error_inj[cmd];
unsigned int mode = (e >> mode_offset) & CEC_ERROR_INJ_MODE_MASK;
if (arg_idx >= 0) {
u8 pos = pin->error_inj_args[cmd][arg_idx];
if (arg)
*arg = pos;
else if (pos != pin->rx_bit)
return false;
}
switch (mode) {
case CEC_ERROR_INJ_MODE_ONCE:
pin->error_inj[cmd] &=
~(CEC_ERROR_INJ_MODE_MASK << mode_offset);
return true;
case CEC_ERROR_INJ_MODE_ALWAYS:
return true;
case CEC_ERROR_INJ_MODE_TOGGLE:
return pin->rx_toggle;
default:
return false;
}
#else
return false;
#endif
}
static bool rx_nack(struct cec_pin *pin)
{
return rx_error_inj(pin, CEC_ERROR_INJ_RX_NACK_OFFSET, -1, NULL);
}
static bool rx_low_drive(struct cec_pin *pin)
{
return rx_error_inj(pin, CEC_ERROR_INJ_RX_LOW_DRIVE_OFFSET,
CEC_ERROR_INJ_RX_LOW_DRIVE_ARG_IDX, NULL);
}
static bool rx_add_byte(struct cec_pin *pin)
{
return rx_error_inj(pin, CEC_ERROR_INJ_RX_ADD_BYTE_OFFSET, -1, NULL);
}
static bool rx_remove_byte(struct cec_pin *pin)
{
return rx_error_inj(pin, CEC_ERROR_INJ_RX_REMOVE_BYTE_OFFSET, -1, NULL);
}
static bool rx_arb_lost(struct cec_pin *pin, u8 *poll)
{
return pin->tx_msg.len == 0 &&
rx_error_inj(pin, CEC_ERROR_INJ_RX_ARB_LOST_OFFSET,
CEC_ERROR_INJ_RX_ARB_LOST_ARG_IDX, poll);
}
static bool tx_error_inj(struct cec_pin *pin, unsigned int mode_offset,
int arg_idx, u8 *arg)
{
#ifdef CONFIG_CEC_PIN_ERROR_INJ
u16 cmd = cec_pin_tx_error_inj(pin);
u64 e = pin->error_inj[cmd];
unsigned int mode = (e >> mode_offset) & CEC_ERROR_INJ_MODE_MASK;
if (arg_idx >= 0) {
u8 pos = pin->error_inj_args[cmd][arg_idx];
if (arg)
*arg = pos;
else if (pos != pin->tx_bit)
return false;
}
switch (mode) {
case CEC_ERROR_INJ_MODE_ONCE:
pin->error_inj[cmd] &=
~(CEC_ERROR_INJ_MODE_MASK << mode_offset);
return true;
case CEC_ERROR_INJ_MODE_ALWAYS:
return true;
case CEC_ERROR_INJ_MODE_TOGGLE:
return pin->tx_toggle;
default:
return false;
}
#else
return false;
#endif
}
static bool tx_no_eom(struct cec_pin *pin)
{
return tx_error_inj(pin, CEC_ERROR_INJ_TX_NO_EOM_OFFSET, -1, NULL);
}
static bool tx_early_eom(struct cec_pin *pin)
{
return tx_error_inj(pin, CEC_ERROR_INJ_TX_EARLY_EOM_OFFSET, -1, NULL);
}
static bool tx_short_bit(struct cec_pin *pin)
{
return tx_error_inj(pin, CEC_ERROR_INJ_TX_SHORT_BIT_OFFSET,
CEC_ERROR_INJ_TX_SHORT_BIT_ARG_IDX, NULL);
}
static bool tx_long_bit(struct cec_pin *pin)
{
return tx_error_inj(pin, CEC_ERROR_INJ_TX_LONG_BIT_OFFSET,
CEC_ERROR_INJ_TX_LONG_BIT_ARG_IDX, NULL);
}
static bool tx_custom_bit(struct cec_pin *pin)
{
return tx_error_inj(pin, CEC_ERROR_INJ_TX_CUSTOM_BIT_OFFSET,
CEC_ERROR_INJ_TX_CUSTOM_BIT_ARG_IDX, NULL);
}
static bool tx_short_start(struct cec_pin *pin)
{
return tx_error_inj(pin, CEC_ERROR_INJ_TX_SHORT_START_OFFSET, -1, NULL);
}
static bool tx_long_start(struct cec_pin *pin)
{
return tx_error_inj(pin, CEC_ERROR_INJ_TX_LONG_START_OFFSET, -1, NULL);
}
static bool tx_custom_start(struct cec_pin *pin)
{
return tx_error_inj(pin, CEC_ERROR_INJ_TX_CUSTOM_START_OFFSET,
-1, NULL);
}
static bool tx_last_bit(struct cec_pin *pin)
{
return tx_error_inj(pin, CEC_ERROR_INJ_TX_LAST_BIT_OFFSET,
CEC_ERROR_INJ_TX_LAST_BIT_ARG_IDX, NULL);
}
static u8 tx_add_bytes(struct cec_pin *pin)
{
u8 bytes;
if (tx_error_inj(pin, CEC_ERROR_INJ_TX_ADD_BYTES_OFFSET,
CEC_ERROR_INJ_TX_ADD_BYTES_ARG_IDX, &bytes))
return bytes;
return 0;
}
static bool tx_remove_byte(struct cec_pin *pin)
{
return tx_error_inj(pin, CEC_ERROR_INJ_TX_REMOVE_BYTE_OFFSET, -1, NULL);
}
static bool tx_low_drive(struct cec_pin *pin)
{
return tx_error_inj(pin, CEC_ERROR_INJ_TX_LOW_DRIVE_OFFSET,
CEC_ERROR_INJ_TX_LOW_DRIVE_ARG_IDX, NULL);
}
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
static void cec_pin_to_idle(struct cec_pin *pin)
{
/*
* Reset all status fields, release the bus and
* go to idle state.
*/
pin->rx_bit = pin->tx_bit = 0;
pin->rx_msg.len = 0;
memset(pin->rx_msg.msg, 0, sizeof(pin->rx_msg.msg));
media: cec-pin.c: use proper ktime accessor functions Use ktime_to_ns/ns_to_ktime. This makes it possible to work with older kernels and the media_build compatibility system. For the mainline kernel these functions are NOPs. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Hans Verkuil <hansverk@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-01 16:37:54 +08:00
pin->ts = ns_to_ktime(0);
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
pin->tx_generated_poll = false;
pin->tx_post_eom = false;
if (pin->state >= CEC_ST_TX_WAIT &&
pin->state <= CEC_ST_TX_LOW_DRIVE)
pin->tx_toggle ^= 1;
if (pin->state >= CEC_ST_RX_START_BIT_LOW &&
pin->state <= CEC_ST_RX_LOW_DRIVE)
pin->rx_toggle ^= 1;
pin->state = CEC_ST_IDLE;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
}
/*
* Handle Transmit-related states
*
* Basic state changes when transmitting:
*
* Idle -> Tx Wait (waiting for the end of signal free time) ->
* Tx Start Bit Low -> Tx Start Bit High ->
*
* Regular data bits + EOM:
* Tx Data 0 Low -> Tx Data 0 High ->
* or:
* Tx Data 1 Low -> Tx Data 1 High ->
*
* First 4 data bits or Ack bit:
* Tx Data 0 Low -> Tx Data 0 High ->
* or:
* Tx Data 1 Low -> Tx Data 1 High -> Tx Data 1 Pre Sample ->
* Tx Data 1 Post Sample ->
*
* After the last Ack go to Idle.
*
* If it detects a Low Drive condition then:
* Tx Wait For High -> Idle
*
* If it loses arbitration, then it switches to state Rx Data Post Sample.
*/
static void cec_pin_tx_states(struct cec_pin *pin, ktime_t ts)
{
bool v;
bool is_ack_bit, ack;
switch (pin->state) {
case CEC_ST_TX_WAIT_FOR_HIGH:
if (cec_pin_read(pin))
cec_pin_to_idle(pin);
break;
case CEC_ST_TX_START_BIT_LOW:
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
if (tx_short_start(pin)) {
/*
* Error Injection: send an invalid (too short)
* start pulse.
*/
pin->state = CEC_ST_TX_START_BIT_HIGH_SHORT;
} else if (tx_long_start(pin)) {
/*
* Error Injection: send an invalid (too long)
* start pulse.
*/
pin->state = CEC_ST_TX_START_BIT_HIGH_LONG;
} else {
pin->state = CEC_ST_TX_START_BIT_HIGH;
}
/* Generate start bit */
cec_pin_high(pin);
break;
case CEC_ST_TX_START_BIT_LOW_CUSTOM:
pin->state = CEC_ST_TX_START_BIT_HIGH_CUSTOM;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
/* Generate start bit */
cec_pin_high(pin);
break;
case CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE:
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
case CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE_SHORT:
case CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE_LONG:
if (pin->tx_nacked) {
cec_pin_to_idle(pin);
pin->tx_msg.len = 0;
if (pin->tx_generated_poll)
break;
pin->work_tx_ts = ts;
pin->work_tx_status = CEC_TX_STATUS_NACK;
wake_up_interruptible(&pin->kthread_waitq);
break;
}
/* fall through */
case CEC_ST_TX_DATA_BIT_0_HIGH:
case CEC_ST_TX_DATA_BIT_0_HIGH_SHORT:
case CEC_ST_TX_DATA_BIT_0_HIGH_LONG:
case CEC_ST_TX_DATA_BIT_1_HIGH:
case CEC_ST_TX_DATA_BIT_1_HIGH_SHORT:
case CEC_ST_TX_DATA_BIT_1_HIGH_LONG:
/*
* If the read value is 1, then all is OK, otherwise we have a
* low drive condition.
*
* Special case: when we generate a poll message due to an
* Arbitration Lost error injection, then ignore this since
* the pin can actually be low in that case.
*/
if (!cec_pin_read(pin) && !pin->tx_generated_poll) {
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
/*
* It's 0, so someone detected an error and pulled the
* line low for 1.5 times the nominal bit period.
*/
pin->tx_msg.len = 0;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
pin->state = CEC_ST_TX_WAIT_FOR_HIGH;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->work_tx_ts = ts;
pin->work_tx_status = CEC_TX_STATUS_LOW_DRIVE;
media: cec-pin: improve status log Keep track of the number of short or long start bits, the number of short or long data bits and the number of initiated or detected low drive conditions. Show this information in the status debugfs log. Helpful when debugging, particularly when doing error injection as well. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-01 15:02:24 +08:00
pin->tx_low_drive_cnt++;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
wake_up_interruptible(&pin->kthread_waitq);
break;
}
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
/* fall through */
case CEC_ST_TX_DATA_BIT_HIGH_CUSTOM:
if (tx_last_bit(pin)) {
/* Error Injection: just stop sending after this bit */
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
cec_pin_to_idle(pin);
pin->tx_msg.len = 0;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
if (pin->tx_generated_poll)
break;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->work_tx_ts = ts;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
pin->work_tx_status = CEC_TX_STATUS_OK;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
wake_up_interruptible(&pin->kthread_waitq);
break;
}
pin->tx_bit++;
/* fall through */
case CEC_ST_TX_START_BIT_HIGH:
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
case CEC_ST_TX_START_BIT_HIGH_SHORT:
case CEC_ST_TX_START_BIT_HIGH_LONG:
case CEC_ST_TX_START_BIT_HIGH_CUSTOM:
if (tx_low_drive(pin)) {
/* Error injection: go to low drive */
cec_pin_low(pin);
pin->state = CEC_ST_TX_LOW_DRIVE;
pin->tx_msg.len = 0;
if (pin->tx_generated_poll)
break;
pin->work_tx_ts = ts;
pin->work_tx_status = CEC_TX_STATUS_LOW_DRIVE;
media: cec-pin: improve status log Keep track of the number of short or long start bits, the number of short or long data bits and the number of initiated or detected low drive conditions. Show this information in the status debugfs log. Helpful when debugging, particularly when doing error injection as well. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-01 15:02:24 +08:00
pin->tx_low_drive_cnt++;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
wake_up_interruptible(&pin->kthread_waitq);
break;
}
if (pin->tx_bit / 10 >= pin->tx_msg.len + pin->tx_extra_bytes) {
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
cec_pin_to_idle(pin);
pin->tx_msg.len = 0;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
if (pin->tx_generated_poll)
break;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->work_tx_ts = ts;
pin->work_tx_status = CEC_TX_STATUS_OK;
wake_up_interruptible(&pin->kthread_waitq);
break;
}
switch (pin->tx_bit % 10) {
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
default: {
/*
* In the CEC_ERROR_INJ_TX_ADD_BYTES case we transmit
* extra bytes, so pin->tx_bit / 10 can become >= 16.
* Generate bit values for those extra bytes instead
* of reading them from the transmit buffer.
*/
unsigned int idx = (pin->tx_bit / 10);
u8 val = idx;
if (idx < pin->tx_msg.len)
val = pin->tx_msg.msg[idx];
v = val & (1 << (7 - (pin->tx_bit % 10)));
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->state = v ? CEC_ST_TX_DATA_BIT_1_LOW :
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
CEC_ST_TX_DATA_BIT_0_LOW;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
break;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
}
case EOM_BIT: {
unsigned int tot_len = pin->tx_msg.len +
pin->tx_extra_bytes;
unsigned int tx_byte_idx = pin->tx_bit / 10;
v = !pin->tx_post_eom && tx_byte_idx == tot_len - 1;
if (tot_len > 1 && tx_byte_idx == tot_len - 2 &&
tx_early_eom(pin)) {
/* Error injection: set EOM one byte early */
v = true;
pin->tx_post_eom = true;
} else if (v && tx_no_eom(pin)) {
/* Error injection: no EOM */
v = false;
}
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->state = v ? CEC_ST_TX_DATA_BIT_1_LOW :
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
CEC_ST_TX_DATA_BIT_0_LOW;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
break;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
}
case ACK_BIT:
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->state = CEC_ST_TX_DATA_BIT_1_LOW;
break;
}
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
if (tx_custom_bit(pin))
pin->state = CEC_ST_TX_DATA_BIT_LOW_CUSTOM;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
cec_pin_low(pin);
break;
case CEC_ST_TX_DATA_BIT_0_LOW:
case CEC_ST_TX_DATA_BIT_1_LOW:
v = pin->state == CEC_ST_TX_DATA_BIT_1_LOW;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
is_ack_bit = pin->tx_bit % 10 == ACK_BIT;
if (v && (pin->tx_bit < 4 || is_ack_bit)) {
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->state = CEC_ST_TX_DATA_BIT_1_HIGH_PRE_SAMPLE;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
} else if (!is_ack_bit && tx_short_bit(pin)) {
/* Error Injection: send an invalid (too short) bit */
pin->state = v ? CEC_ST_TX_DATA_BIT_1_HIGH_SHORT :
CEC_ST_TX_DATA_BIT_0_HIGH_SHORT;
} else if (!is_ack_bit && tx_long_bit(pin)) {
/* Error Injection: send an invalid (too long) bit */
pin->state = v ? CEC_ST_TX_DATA_BIT_1_HIGH_LONG :
CEC_ST_TX_DATA_BIT_0_HIGH_LONG;
} else {
pin->state = v ? CEC_ST_TX_DATA_BIT_1_HIGH :
CEC_ST_TX_DATA_BIT_0_HIGH;
}
cec_pin_high(pin);
break;
case CEC_ST_TX_DATA_BIT_LOW_CUSTOM:
pin->state = CEC_ST_TX_DATA_BIT_HIGH_CUSTOM;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
cec_pin_high(pin);
break;
case CEC_ST_TX_DATA_BIT_1_HIGH_PRE_SAMPLE:
/* Read the CEC value at the sample time */
v = cec_pin_read(pin);
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
is_ack_bit = pin->tx_bit % 10 == ACK_BIT;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
/*
* If v == 0 and we're within the first 4 bits
* of the initiator, then someone else started
* transmitting and we lost the arbitration
* (i.e. the logical address of the other
* transmitter has more leading 0 bits in the
* initiator).
*/
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
if (!v && !is_ack_bit && !pin->tx_generated_poll) {
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->tx_msg.len = 0;
pin->work_tx_ts = ts;
pin->work_tx_status = CEC_TX_STATUS_ARB_LOST;
wake_up_interruptible(&pin->kthread_waitq);
pin->rx_bit = pin->tx_bit;
pin->tx_bit = 0;
memset(pin->rx_msg.msg, 0, sizeof(pin->rx_msg.msg));
pin->rx_msg.msg[0] = pin->tx_msg.msg[0];
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
pin->rx_msg.msg[0] &= (0xff << (8 - pin->rx_bit));
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->rx_msg.len = 0;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
pin->ts = ktime_sub_us(ts, CEC_TIM_DATA_BIT_SAMPLE);
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->state = CEC_ST_RX_DATA_POST_SAMPLE;
pin->rx_bit++;
break;
}
pin->state = CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
if (!is_ack_bit && tx_short_bit(pin)) {
/* Error Injection: send an invalid (too short) bit */
pin->state = CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE_SHORT;
} else if (!is_ack_bit && tx_long_bit(pin)) {
/* Error Injection: send an invalid (too long) bit */
pin->state = CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE_LONG;
}
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
if (!is_ack_bit)
break;
/* Was the message ACKed? */
ack = cec_msg_is_broadcast(&pin->tx_msg) ? v : !v;
media: cec-pin: fix broken tx_ignore_nack_until_eom error injection If the tx_ignore_nack_until_eom error injection was activated, then tx_nacked was never set instead of setting it when the last byte of the message was transmitted. As a result the transmit was marked as OK, when it should have been NACKed. Modify the condition so that it always sets tx_nacked when the last byte of the message was transmitted. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Cc: <stable@vger.kernel.org> # for v4.17 and up Signed-off-by: Hans Verkuil <hansverk@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-11-14 16:37:53 +08:00
if (!ack && (!pin->tx_ignore_nack_until_eom ||
pin->tx_bit / 10 == pin->tx_msg.len - 1) &&
!pin->tx_post_eom) {
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
/*
* Note: the CEC spec is ambiguous regarding
* what action to take when a NACK appears
* before the last byte of the payload was
* transmitted: either stop transmitting
* immediately, or wait until the last byte
* was transmitted.
*
* Most CEC implementations appear to stop
* immediately, and that's what we do here
* as well.
*/
pin->tx_nacked = true;
}
break;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
case CEC_ST_TX_PULSE_LOW_CUSTOM:
cec_pin_high(pin);
pin->state = CEC_ST_TX_PULSE_HIGH_CUSTOM;
break;
case CEC_ST_TX_PULSE_HIGH_CUSTOM:
cec_pin_to_idle(pin);
break;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
default:
break;
}
}
/*
* Handle Receive-related states
*
* Basic state changes when receiving:
*
* Rx Start Bit Low -> Rx Start Bit High ->
* Regular data bits + EOM:
* Rx Data Sample -> Rx Data Post Sample -> Rx Data High ->
* Ack bit 0:
* Rx Ack Low -> Rx Ack Low Post -> Rx Data High ->
* Ack bit 1:
* Rx Ack High Post -> Rx Data High ->
* Ack bit 0 && EOM:
* Rx Ack Low -> Rx Ack Low Post -> Rx Ack Finish -> Idle
*/
static void cec_pin_rx_states(struct cec_pin *pin, ktime_t ts)
{
s32 delta;
bool v;
bool ack;
bool bcast, for_us;
u8 dest;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
u8 poll;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
switch (pin->state) {
/* Receive states */
case CEC_ST_RX_START_BIT_LOW:
v = cec_pin_read(pin);
if (!v)
break;
pin->state = CEC_ST_RX_START_BIT_HIGH;
delta = ktime_us_delta(ts, pin->ts);
/* Start bit low is too short, go back to idle */
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
if (delta < CEC_TIM_START_BIT_LOW_MIN - CEC_TIM_IDLE_SAMPLE) {
media: cec-pin: improve status log Keep track of the number of short or long start bits, the number of short or long data bits and the number of initiated or detected low drive conditions. Show this information in the status debugfs log. Helpful when debugging, particularly when doing error injection as well. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-01 15:02:24 +08:00
if (!pin->rx_start_bit_low_too_short_cnt++) {
media: cec-pin: Fixed ktime_t to ns conversion Older Kernels use a struct for ktime_t, which requires the conversion function ktime_to_ns to be used on some places. With this patch it will compile now also for older Kernel versions. Signed-off-by: Jasmin Jessich <jasmin@anw.at> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-25 08:29:46 +08:00
pin->rx_start_bit_low_too_short_ts = ktime_to_ns(pin->ts);
media: cec-pin: improve status log Keep track of the number of short or long start bits, the number of short or long data bits and the number of initiated or detected low drive conditions. Show this information in the status debugfs log. Helpful when debugging, particularly when doing error injection as well. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-01 15:02:24 +08:00
pin->rx_start_bit_low_too_short_delta = delta;
}
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
cec_pin_to_idle(pin);
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
break;
}
if (rx_arb_lost(pin, &poll)) {
cec_msg_init(&pin->tx_msg, poll >> 4, poll & 0xf);
pin->tx_generated_poll = true;
pin->tx_extra_bytes = 0;
pin->state = CEC_ST_TX_START_BIT_HIGH;
pin->ts = ts;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
}
break;
case CEC_ST_RX_START_BIT_HIGH:
v = cec_pin_read(pin);
delta = ktime_us_delta(ts, pin->ts);
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
/*
* Unfortunately the spec does not specify when to give up
* and go to idle. We just pick TOTAL_LONG.
*/
if (v && delta > CEC_TIM_START_BIT_TOTAL_LONG) {
media: cec-pin: improve status log Keep track of the number of short or long start bits, the number of short or long data bits and the number of initiated or detected low drive conditions. Show this information in the status debugfs log. Helpful when debugging, particularly when doing error injection as well. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-01 15:02:24 +08:00
pin->rx_start_bit_too_long_cnt++;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
cec_pin_to_idle(pin);
break;
}
if (v)
break;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
/* Start bit is too short, go back to idle */
if (delta < CEC_TIM_START_BIT_TOTAL_MIN - CEC_TIM_IDLE_SAMPLE) {
media: cec-pin: improve status log Keep track of the number of short or long start bits, the number of short or long data bits and the number of initiated or detected low drive conditions. Show this information in the status debugfs log. Helpful when debugging, particularly when doing error injection as well. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-01 15:02:24 +08:00
if (!pin->rx_start_bit_too_short_cnt++) {
media: cec-pin: Fixed ktime_t to ns conversion Older Kernels use a struct for ktime_t, which requires the conversion function ktime_to_ns to be used on some places. With this patch it will compile now also for older Kernel versions. Signed-off-by: Jasmin Jessich <jasmin@anw.at> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-25 08:29:46 +08:00
pin->rx_start_bit_too_short_ts = ktime_to_ns(pin->ts);
media: cec-pin: improve status log Keep track of the number of short or long start bits, the number of short or long data bits and the number of initiated or detected low drive conditions. Show this information in the status debugfs log. Helpful when debugging, particularly when doing error injection as well. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-01 15:02:24 +08:00
pin->rx_start_bit_too_short_delta = delta;
}
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
cec_pin_to_idle(pin);
break;
}
if (rx_low_drive(pin)) {
/* Error injection: go to low drive */
cec_pin_low(pin);
pin->state = CEC_ST_RX_LOW_DRIVE;
media: cec-pin: improve status log Keep track of the number of short or long start bits, the number of short or long data bits and the number of initiated or detected low drive conditions. Show this information in the status debugfs log. Helpful when debugging, particularly when doing error injection as well. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-01 15:02:24 +08:00
pin->rx_low_drive_cnt++;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
break;
}
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->state = CEC_ST_RX_DATA_SAMPLE;
pin->ts = ts;
pin->rx_eom = false;
break;
case CEC_ST_RX_DATA_SAMPLE:
v = cec_pin_read(pin);
pin->state = CEC_ST_RX_DATA_POST_SAMPLE;
switch (pin->rx_bit % 10) {
default:
if (pin->rx_bit / 10 < CEC_MAX_MSG_SIZE)
pin->rx_msg.msg[pin->rx_bit / 10] |=
v << (7 - (pin->rx_bit % 10));
break;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
case EOM_BIT:
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->rx_eom = v;
pin->rx_msg.len = pin->rx_bit / 10 + 1;
break;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
case ACK_BIT:
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
break;
}
pin->rx_bit++;
break;
case CEC_ST_RX_DATA_POST_SAMPLE:
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
pin->state = CEC_ST_RX_DATA_WAIT_FOR_LOW;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
break;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
case CEC_ST_RX_DATA_WAIT_FOR_LOW:
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
v = cec_pin_read(pin);
delta = ktime_us_delta(ts, pin->ts);
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
/*
* Unfortunately the spec does not specify when to give up
* and go to idle. We just pick TOTAL_LONG.
*/
if (v && delta > CEC_TIM_DATA_BIT_TOTAL_LONG) {
media: cec-pin: improve status log Keep track of the number of short or long start bits, the number of short or long data bits and the number of initiated or detected low drive conditions. Show this information in the status debugfs log. Helpful when debugging, particularly when doing error injection as well. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-01 15:02:24 +08:00
pin->rx_data_bit_too_long_cnt++;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
cec_pin_to_idle(pin);
break;
}
if (v)
break;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
if (rx_low_drive(pin)) {
/* Error injection: go to low drive */
cec_pin_low(pin);
pin->state = CEC_ST_RX_LOW_DRIVE;
media: cec-pin: improve status log Keep track of the number of short or long start bits, the number of short or long data bits and the number of initiated or detected low drive conditions. Show this information in the status debugfs log. Helpful when debugging, particularly when doing error injection as well. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-01 15:02:24 +08:00
pin->rx_low_drive_cnt++;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
break;
}
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
/*
* Go to low drive state when the total bit time is
* too short.
*/
if (delta < CEC_TIM_DATA_BIT_TOTAL_MIN) {
media: cec-pin: improve status log Keep track of the number of short or long start bits, the number of short or long data bits and the number of initiated or detected low drive conditions. Show this information in the status debugfs log. Helpful when debugging, particularly when doing error injection as well. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-01 15:02:24 +08:00
if (!pin->rx_data_bit_too_short_cnt++) {
media: cec-pin: Fixed ktime_t to ns conversion Older Kernels use a struct for ktime_t, which requires the conversion function ktime_to_ns to be used on some places. With this patch it will compile now also for older Kernel versions. Signed-off-by: Jasmin Jessich <jasmin@anw.at> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-25 08:29:46 +08:00
pin->rx_data_bit_too_short_ts = ktime_to_ns(pin->ts);
media: cec-pin: improve status log Keep track of the number of short or long start bits, the number of short or long data bits and the number of initiated or detected low drive conditions. Show this information in the status debugfs log. Helpful when debugging, particularly when doing error injection as well. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-01 15:02:24 +08:00
pin->rx_data_bit_too_short_delta = delta;
}
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
cec_pin_low(pin);
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
pin->state = CEC_ST_RX_LOW_DRIVE;
media: cec-pin: improve status log Keep track of the number of short or long start bits, the number of short or long data bits and the number of initiated or detected low drive conditions. Show this information in the status debugfs log. Helpful when debugging, particularly when doing error injection as well. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-01 15:02:24 +08:00
pin->rx_low_drive_cnt++;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
break;
}
pin->ts = ts;
if (pin->rx_bit % 10 != 9) {
pin->state = CEC_ST_RX_DATA_SAMPLE;
break;
}
dest = cec_msg_destination(&pin->rx_msg);
bcast = dest == CEC_LOG_ADDR_BROADCAST;
/* for_us == broadcast or directed to us */
for_us = bcast || (pin->la_mask & (1 << dest));
/* ACK bit value */
ack = bcast ? 1 : !for_us;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
if (for_us && rx_nack(pin)) {
/* Error injection: toggle the ACK bit */
ack = !ack;
}
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
if (ack) {
/* No need to write to the bus, just wait */
pin->state = CEC_ST_RX_ACK_HIGH_POST;
break;
}
cec_pin_low(pin);
pin->state = CEC_ST_RX_ACK_LOW;
break;
case CEC_ST_RX_ACK_LOW:
cec_pin_high(pin);
pin->state = CEC_ST_RX_ACK_LOW_POST;
break;
case CEC_ST_RX_ACK_LOW_POST:
case CEC_ST_RX_ACK_HIGH_POST:
v = cec_pin_read(pin);
if (v && pin->rx_eom) {
pin->work_rx_msg = pin->rx_msg;
media: cec-pin.c: use proper ktime accessor functions Use ktime_to_ns/ns_to_ktime. This makes it possible to work with older kernels and the media_build compatibility system. For the mainline kernel these functions are NOPs. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Hans Verkuil <hansverk@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-01 16:37:54 +08:00
pin->work_rx_msg.rx_ts = ktime_to_ns(ts);
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
wake_up_interruptible(&pin->kthread_waitq);
pin->ts = ts;
pin->state = CEC_ST_RX_ACK_FINISH;
break;
}
pin->rx_bit++;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
pin->state = CEC_ST_RX_DATA_WAIT_FOR_LOW;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
break;
case CEC_ST_RX_ACK_FINISH:
cec_pin_to_idle(pin);
break;
default:
break;
}
}
/*
* Main timer function
*
*/
static enum hrtimer_restart cec_pin_timer(struct hrtimer *timer)
{
struct cec_pin *pin = container_of(timer, struct cec_pin, timer);
struct cec_adapter *adap = pin->adap;
ktime_t ts;
s32 delta;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
u32 usecs;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
ts = ktime_get();
media: cec-pin.c: use proper ktime accessor functions Use ktime_to_ns/ns_to_ktime. This makes it possible to work with older kernels and the media_build compatibility system. For the mainline kernel these functions are NOPs. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Hans Verkuil <hansverk@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-01 16:37:54 +08:00
if (ktime_to_ns(pin->timer_ts)) {
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
delta = ktime_us_delta(ts, pin->timer_ts);
pin->timer_cnt++;
if (delta > 100 && pin->state != CEC_ST_IDLE) {
/* Keep track of timer overruns */
pin->timer_sum_overrun += delta;
pin->timer_100ms_overruns++;
if (delta > 300)
pin->timer_300ms_overruns++;
if (delta > pin->timer_max_overrun)
pin->timer_max_overrun = delta;
}
}
if (adap->monitor_pin_cnt)
cec_pin_read(pin);
if (pin->wait_usecs) {
/*
* If we are monitoring the pin, then we have to
* sample at regular intervals.
*/
if (pin->wait_usecs > 150) {
pin->wait_usecs -= 100;
pin->timer_ts = ktime_add_us(ts, 100);
media: cec-pin.c: use proper ktime accessor functions Use ktime_to_ns/ns_to_ktime. This makes it possible to work with older kernels and the media_build compatibility system. For the mainline kernel these functions are NOPs. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Hans Verkuil <hansverk@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-01 16:37:54 +08:00
hrtimer_forward_now(timer, ns_to_ktime(100000));
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
return HRTIMER_RESTART;
}
if (pin->wait_usecs > 100) {
pin->wait_usecs /= 2;
pin->timer_ts = ktime_add_us(ts, pin->wait_usecs);
media: cec-pin.c: use proper ktime accessor functions Use ktime_to_ns/ns_to_ktime. This makes it possible to work with older kernels and the media_build compatibility system. For the mainline kernel these functions are NOPs. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Hans Verkuil <hansverk@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-01 16:37:54 +08:00
hrtimer_forward_now(timer,
ns_to_ktime(pin->wait_usecs * 1000));
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
return HRTIMER_RESTART;
}
pin->timer_ts = ktime_add_us(ts, pin->wait_usecs);
media: cec-pin.c: use proper ktime accessor functions Use ktime_to_ns/ns_to_ktime. This makes it possible to work with older kernels and the media_build compatibility system. For the mainline kernel these functions are NOPs. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Hans Verkuil <hansverk@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-01 16:37:54 +08:00
hrtimer_forward_now(timer,
ns_to_ktime(pin->wait_usecs * 1000));
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->wait_usecs = 0;
return HRTIMER_RESTART;
}
switch (pin->state) {
/* Transmit states */
case CEC_ST_TX_WAIT_FOR_HIGH:
case CEC_ST_TX_START_BIT_LOW:
case CEC_ST_TX_START_BIT_HIGH:
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
case CEC_ST_TX_START_BIT_HIGH_SHORT:
case CEC_ST_TX_START_BIT_HIGH_LONG:
case CEC_ST_TX_START_BIT_LOW_CUSTOM:
case CEC_ST_TX_START_BIT_HIGH_CUSTOM:
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
case CEC_ST_TX_DATA_BIT_0_LOW:
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
case CEC_ST_TX_DATA_BIT_0_HIGH:
case CEC_ST_TX_DATA_BIT_0_HIGH_SHORT:
case CEC_ST_TX_DATA_BIT_0_HIGH_LONG:
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
case CEC_ST_TX_DATA_BIT_1_LOW:
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
case CEC_ST_TX_DATA_BIT_1_HIGH:
case CEC_ST_TX_DATA_BIT_1_HIGH_SHORT:
case CEC_ST_TX_DATA_BIT_1_HIGH_LONG:
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
case CEC_ST_TX_DATA_BIT_1_HIGH_PRE_SAMPLE:
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
case CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE:
case CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE_SHORT:
case CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE_LONG:
case CEC_ST_TX_DATA_BIT_LOW_CUSTOM:
case CEC_ST_TX_DATA_BIT_HIGH_CUSTOM:
case CEC_ST_TX_PULSE_LOW_CUSTOM:
case CEC_ST_TX_PULSE_HIGH_CUSTOM:
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
cec_pin_tx_states(pin, ts);
break;
/* Receive states */
case CEC_ST_RX_START_BIT_LOW:
case CEC_ST_RX_START_BIT_HIGH:
case CEC_ST_RX_DATA_SAMPLE:
case CEC_ST_RX_DATA_POST_SAMPLE:
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
case CEC_ST_RX_DATA_WAIT_FOR_LOW:
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
case CEC_ST_RX_ACK_LOW:
case CEC_ST_RX_ACK_LOW_POST:
case CEC_ST_RX_ACK_HIGH_POST:
case CEC_ST_RX_ACK_FINISH:
cec_pin_rx_states(pin, ts);
break;
case CEC_ST_IDLE:
case CEC_ST_TX_WAIT:
if (!cec_pin_high(pin)) {
/* Start bit, switch to receive state */
pin->ts = ts;
pin->state = CEC_ST_RX_START_BIT_LOW;
media: cec-gpio: select correct Signal Free Time If a receive is in progress or starts before the transmit has a chance, then lower the Signal Free Time of the upcoming transmit to no more than CEC_SIGNAL_FREE_TIME_NEW_INITIATOR. This is per the specification requirements. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-10-05 20:51:45 +08:00
/*
* If a transmit is pending, then that transmit should
* use a signal free time of no more than
* CEC_SIGNAL_FREE_TIME_NEW_INITIATOR since it will
* have a new initiator due to the receive that is now
* starting.
*/
if (pin->tx_msg.len && pin->tx_signal_free_time >
CEC_SIGNAL_FREE_TIME_NEW_INITIATOR)
pin->tx_signal_free_time =
CEC_SIGNAL_FREE_TIME_NEW_INITIATOR;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
break;
}
media: cec-pin.c: use proper ktime accessor functions Use ktime_to_ns/ns_to_ktime. This makes it possible to work with older kernels and the media_build compatibility system. For the mainline kernel these functions are NOPs. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Hans Verkuil <hansverk@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-01 16:37:54 +08:00
if (ktime_to_ns(pin->ts) == 0)
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->ts = ts;
if (pin->tx_msg.len) {
/*
* Check if the bus has been free for long enough
* so we can kick off the pending transmit.
*/
delta = ktime_us_delta(ts, pin->ts);
if (delta / CEC_TIM_DATA_BIT_TOTAL >
pin->tx_signal_free_time) {
pin->tx_nacked = false;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
if (tx_custom_start(pin))
pin->state = CEC_ST_TX_START_BIT_LOW_CUSTOM;
else
pin->state = CEC_ST_TX_START_BIT_LOW;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
/* Generate start bit */
cec_pin_low(pin);
break;
}
if (delta / CEC_TIM_DATA_BIT_TOTAL >
pin->tx_signal_free_time - 1)
pin->state = CEC_ST_TX_WAIT;
break;
}
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
if (pin->tx_custom_pulse && pin->state == CEC_ST_IDLE) {
pin->tx_custom_pulse = false;
/* Generate custom pulse */
cec_pin_low(pin);
pin->state = CEC_ST_TX_PULSE_LOW_CUSTOM;
break;
}
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
if (pin->state != CEC_ST_IDLE || pin->ops->enable_irq == NULL ||
pin->enable_irq_failed || adap->is_configuring ||
adap->is_configured || adap->monitor_all_cnt)
break;
/* Switch to interrupt mode */
media: cec-pin: fix irq handling The free_irq() function could be called from interrupt context, which is invalid. Move this to the thread. In the interrupt handler we just request that the thread disables the irq. This is done through an atomic so we don't need to add any spinlocks. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-08-16 15:13:02 +08:00
atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_ENABLE);
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->state = CEC_ST_RX_IRQ;
wake_up_interruptible(&pin->kthread_waitq);
return HRTIMER_NORESTART;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
case CEC_ST_TX_LOW_DRIVE:
case CEC_ST_RX_LOW_DRIVE:
cec_pin_high(pin);
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
cec_pin_to_idle(pin);
break;
default:
break;
}
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
switch (pin->state) {
case CEC_ST_TX_START_BIT_LOW_CUSTOM:
case CEC_ST_TX_DATA_BIT_LOW_CUSTOM:
case CEC_ST_TX_PULSE_LOW_CUSTOM:
usecs = pin->tx_custom_low_usecs;
break;
case CEC_ST_TX_START_BIT_HIGH_CUSTOM:
case CEC_ST_TX_DATA_BIT_HIGH_CUSTOM:
case CEC_ST_TX_PULSE_HIGH_CUSTOM:
usecs = pin->tx_custom_high_usecs;
break;
default:
usecs = states[pin->state].usecs;
break;
}
if (!adap->monitor_pin_cnt || usecs <= 150) {
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->wait_usecs = 0;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
pin->timer_ts = ktime_add_us(ts, usecs);
media: cec-pin.c: use proper ktime accessor functions Use ktime_to_ns/ns_to_ktime. This makes it possible to work with older kernels and the media_build compatibility system. For the mainline kernel these functions are NOPs. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Hans Verkuil <hansverk@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-01 16:37:54 +08:00
hrtimer_forward_now(timer,
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
ns_to_ktime(usecs * 1000));
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
return HRTIMER_RESTART;
}
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
pin->wait_usecs = usecs - 100;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->timer_ts = ktime_add_us(ts, 100);
media: cec-pin.c: use proper ktime accessor functions Use ktime_to_ns/ns_to_ktime. This makes it possible to work with older kernels and the media_build compatibility system. For the mainline kernel these functions are NOPs. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Hans Verkuil <hansverk@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-01 16:37:54 +08:00
hrtimer_forward_now(timer, ns_to_ktime(100000));
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
return HRTIMER_RESTART;
}
static int cec_pin_thread_func(void *_adap)
{
struct cec_adapter *adap = _adap;
struct cec_pin *pin = adap->pin;
for (;;) {
wait_event_interruptible(pin->kthread_waitq,
kthread_should_stop() ||
pin->work_rx_msg.len ||
pin->work_tx_status ||
media: cec-pin: fix irq handling The free_irq() function could be called from interrupt context, which is invalid. Move this to the thread. In the interrupt handler we just request that the thread disables the irq. This is done through an atomic so we don't need to add any spinlocks. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-08-16 15:13:02 +08:00
atomic_read(&pin->work_irq_change) ||
media: cec: improve CEC pin event handling It turns out that the struct cec_fh event buffer size of 64 events (64 for CEC_EVENT_PIN_CEC_LOW and 64 for _HIGH) is too small. It's about 160 ms worth of events and if the Raspberry Pi is busy, then it might take too long for the application to be scheduled so that it can drain the pending events. Increase these buffers to 800 events which is at least 2 seconds worth of events. There is also a FIFO in between the interrupt and the cec-pin thread. The thread passes the events on to the CEC core. It is important that should this FIFO fill up the cec core will be informed that events have been lost so this can be communicated to the user by setting CEC_EVENT_FL_DROPPED_EVENTS. It is very hard to debug CEC problems if events were lost without informing the user of that fact. If events were dropped due to the FIFO filling up, then the debugfs status file will let you know how many events were dropped. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-07 05:20:00 +08:00
atomic_read(&pin->work_pin_num_events));
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
if (pin->work_rx_msg.len) {
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
struct cec_msg *msg = &pin->work_rx_msg;
if (msg->len > 1 && msg->len < CEC_MAX_MSG_SIZE &&
rx_add_byte(pin)) {
/* Error injection: add byte to the message */
msg->msg[msg->len++] = 0x55;
}
if (msg->len > 2 && rx_remove_byte(pin)) {
/* Error injection: remove byte from message */
msg->len--;
}
if (msg->len > CEC_MAX_MSG_SIZE)
msg->len = CEC_MAX_MSG_SIZE;
cec_received_msg_ts(adap, msg,
media: cec-pin.c: use proper ktime accessor functions Use ktime_to_ns/ns_to_ktime. This makes it possible to work with older kernels and the media_build compatibility system. For the mainline kernel these functions are NOPs. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Hans Verkuil <hansverk@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-01 16:37:54 +08:00
ns_to_ktime(pin->work_rx_msg.rx_ts));
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
msg->len = 0;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
}
if (pin->work_tx_status) {
unsigned int tx_status = pin->work_tx_status;
pin->work_tx_status = 0;
cec_transmit_attempt_done_ts(adap, tx_status,
pin->work_tx_ts);
}
media: cec-pin: fix irq handling The free_irq() function could be called from interrupt context, which is invalid. Move this to the thread. In the interrupt handler we just request that the thread disables the irq. This is done through an atomic so we don't need to add any spinlocks. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-08-16 15:13:02 +08:00
media: cec: improve CEC pin event handling It turns out that the struct cec_fh event buffer size of 64 events (64 for CEC_EVENT_PIN_CEC_LOW and 64 for _HIGH) is too small. It's about 160 ms worth of events and if the Raspberry Pi is busy, then it might take too long for the application to be scheduled so that it can drain the pending events. Increase these buffers to 800 events which is at least 2 seconds worth of events. There is also a FIFO in between the interrupt and the cec-pin thread. The thread passes the events on to the CEC core. It is important that should this FIFO fill up the cec core will be informed that events have been lost so this can be communicated to the user by setting CEC_EVENT_FL_DROPPED_EVENTS. It is very hard to debug CEC problems if events were lost without informing the user of that fact. If events were dropped due to the FIFO filling up, then the debugfs status file will let you know how many events were dropped. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-07 05:20:00 +08:00
while (atomic_read(&pin->work_pin_num_events)) {
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
unsigned int idx = pin->work_pin_events_rd;
media: cec: improve CEC pin event handling It turns out that the struct cec_fh event buffer size of 64 events (64 for CEC_EVENT_PIN_CEC_LOW and 64 for _HIGH) is too small. It's about 160 ms worth of events and if the Raspberry Pi is busy, then it might take too long for the application to be scheduled so that it can drain the pending events. Increase these buffers to 800 events which is at least 2 seconds worth of events. There is also a FIFO in between the interrupt and the cec-pin thread. The thread passes the events on to the CEC core. It is important that should this FIFO fill up the cec core will be informed that events have been lost so this can be communicated to the user by setting CEC_EVENT_FL_DROPPED_EVENTS. It is very hard to debug CEC problems if events were lost without informing the user of that fact. If events were dropped due to the FIFO filling up, then the debugfs status file will let you know how many events were dropped. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-07 05:20:00 +08:00
u8 v = pin->work_pin_events[idx];
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
media: cec: rename pin events/function The CEC_EVENT_PIN_LOW/HIGH defines and the cec_queue_pin_event() function did not specify that these were about CEC pin events. Since in the future there will also be HPD pin events it is wise to rename the event defines and function to CEC_EVENT_PIN_CEC_LOW/HIGH and cec_queue_pin_cec_event() now before these become part of the ABI. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-08-16 03:26:25 +08:00
cec_queue_pin_cec_event(adap,
media: cec: improve CEC pin event handling It turns out that the struct cec_fh event buffer size of 64 events (64 for CEC_EVENT_PIN_CEC_LOW and 64 for _HIGH) is too small. It's about 160 ms worth of events and if the Raspberry Pi is busy, then it might take too long for the application to be scheduled so that it can drain the pending events. Increase these buffers to 800 events which is at least 2 seconds worth of events. There is also a FIFO in between the interrupt and the cec-pin thread. The thread passes the events on to the CEC core. It is important that should this FIFO fill up the cec core will be informed that events have been lost so this can be communicated to the user by setting CEC_EVENT_FL_DROPPED_EVENTS. It is very hard to debug CEC problems if events were lost without informing the user of that fact. If events were dropped due to the FIFO filling up, then the debugfs status file will let you know how many events were dropped. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-07 05:20:00 +08:00
v & CEC_PIN_EVENT_FL_IS_HIGH,
v & CEC_PIN_EVENT_FL_DROPPED,
media: cec: rename pin events/function The CEC_EVENT_PIN_LOW/HIGH defines and the cec_queue_pin_event() function did not specify that these were about CEC pin events. Since in the future there will also be HPD pin events it is wise to rename the event defines and function to CEC_EVENT_PIN_CEC_LOW/HIGH and cec_queue_pin_cec_event() now before these become part of the ABI. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-08-16 03:26:25 +08:00
pin->work_pin_ts[idx]);
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->work_pin_events_rd = (idx + 1) % CEC_NUM_PIN_EVENTS;
media: cec: improve CEC pin event handling It turns out that the struct cec_fh event buffer size of 64 events (64 for CEC_EVENT_PIN_CEC_LOW and 64 for _HIGH) is too small. It's about 160 ms worth of events and if the Raspberry Pi is busy, then it might take too long for the application to be scheduled so that it can drain the pending events. Increase these buffers to 800 events which is at least 2 seconds worth of events. There is also a FIFO in between the interrupt and the cec-pin thread. The thread passes the events on to the CEC core. It is important that should this FIFO fill up the cec core will be informed that events have been lost so this can be communicated to the user by setting CEC_EVENT_FL_DROPPED_EVENTS. It is very hard to debug CEC problems if events were lost without informing the user of that fact. If events were dropped due to the FIFO filling up, then the debugfs status file will let you know how many events were dropped. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-07 05:20:00 +08:00
atomic_dec(&pin->work_pin_num_events);
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
}
media: cec-pin: fix irq handling The free_irq() function could be called from interrupt context, which is invalid. Move this to the thread. In the interrupt handler we just request that the thread disables the irq. This is done through an atomic so we don't need to add any spinlocks. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-08-16 15:13:02 +08:00
switch (atomic_xchg(&pin->work_irq_change,
CEC_PIN_IRQ_UNCHANGED)) {
case CEC_PIN_IRQ_DISABLE:
pin->ops->disable_irq(adap);
cec_pin_high(pin);
cec_pin_to_idle(pin);
media: cec-pin.c: use proper ktime accessor functions Use ktime_to_ns/ns_to_ktime. This makes it possible to work with older kernels and the media_build compatibility system. For the mainline kernel these functions are NOPs. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Hans Verkuil <hansverk@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-01 16:37:54 +08:00
hrtimer_start(&pin->timer, ns_to_ktime(0),
HRTIMER_MODE_REL);
media: cec-pin: fix irq handling The free_irq() function could be called from interrupt context, which is invalid. Move this to the thread. In the interrupt handler we just request that the thread disables the irq. This is done through an atomic so we don't need to add any spinlocks. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-08-16 15:13:02 +08:00
break;
case CEC_PIN_IRQ_ENABLE:
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->enable_irq_failed = !pin->ops->enable_irq(adap);
if (pin->enable_irq_failed) {
cec_pin_to_idle(pin);
media: cec-pin.c: use proper ktime accessor functions Use ktime_to_ns/ns_to_ktime. This makes it possible to work with older kernels and the media_build compatibility system. For the mainline kernel these functions are NOPs. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Hans Verkuil <hansverk@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-01 16:37:54 +08:00
hrtimer_start(&pin->timer, ns_to_ktime(0),
HRTIMER_MODE_REL);
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
}
media: cec-pin: fix irq handling The free_irq() function could be called from interrupt context, which is invalid. Move this to the thread. In the interrupt handler we just request that the thread disables the irq. This is done through an atomic so we don't need to add any spinlocks. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-08-16 15:13:02 +08:00
break;
default:
break;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
}
media: cec-pin: fix irq handling The free_irq() function could be called from interrupt context, which is invalid. Move this to the thread. In the interrupt handler we just request that the thread disables the irq. This is done through an atomic so we don't need to add any spinlocks. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-08-16 15:13:02 +08:00
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
if (kthread_should_stop())
break;
}
return 0;
}
static int cec_pin_adap_enable(struct cec_adapter *adap, bool enable)
{
struct cec_pin *pin = adap->pin;
pin->enabled = enable;
if (enable) {
media: cec: improve CEC pin event handling It turns out that the struct cec_fh event buffer size of 64 events (64 for CEC_EVENT_PIN_CEC_LOW and 64 for _HIGH) is too small. It's about 160 ms worth of events and if the Raspberry Pi is busy, then it might take too long for the application to be scheduled so that it can drain the pending events. Increase these buffers to 800 events which is at least 2 seconds worth of events. There is also a FIFO in between the interrupt and the cec-pin thread. The thread passes the events on to the CEC core. It is important that should this FIFO fill up the cec core will be informed that events have been lost so this can be communicated to the user by setting CEC_EVENT_FL_DROPPED_EVENTS. It is very hard to debug CEC problems if events were lost without informing the user of that fact. If events were dropped due to the FIFO filling up, then the debugfs status file will let you know how many events were dropped. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-07 05:20:00 +08:00
atomic_set(&pin->work_pin_num_events, 0);
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->work_pin_events_rd = pin->work_pin_events_wr = 0;
media: cec: improve CEC pin event handling It turns out that the struct cec_fh event buffer size of 64 events (64 for CEC_EVENT_PIN_CEC_LOW and 64 for _HIGH) is too small. It's about 160 ms worth of events and if the Raspberry Pi is busy, then it might take too long for the application to be scheduled so that it can drain the pending events. Increase these buffers to 800 events which is at least 2 seconds worth of events. There is also a FIFO in between the interrupt and the cec-pin thread. The thread passes the events on to the CEC core. It is important that should this FIFO fill up the cec core will be informed that events have been lost so this can be communicated to the user by setting CEC_EVENT_FL_DROPPED_EVENTS. It is very hard to debug CEC problems if events were lost without informing the user of that fact. If events were dropped due to the FIFO filling up, then the debugfs status file will let you know how many events were dropped. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-07 05:20:00 +08:00
pin->work_pin_events_dropped = false;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
cec_pin_read(pin);
cec_pin_to_idle(pin);
pin->tx_msg.len = 0;
media: cec-pin.c: use proper ktime accessor functions Use ktime_to_ns/ns_to_ktime. This makes it possible to work with older kernels and the media_build compatibility system. For the mainline kernel these functions are NOPs. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Hans Verkuil <hansverk@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-01 16:37:54 +08:00
pin->timer_ts = ns_to_ktime(0);
media: cec-pin: fix irq handling The free_irq() function could be called from interrupt context, which is invalid. Move this to the thread. In the interrupt handler we just request that the thread disables the irq. This is done through an atomic so we don't need to add any spinlocks. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-08-16 15:13:02 +08:00
atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_UNCHANGED);
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->kthread = kthread_run(cec_pin_thread_func, adap,
"cec-pin");
if (IS_ERR(pin->kthread)) {
pr_err("cec-pin: kernel_thread() failed\n");
return PTR_ERR(pin->kthread);
}
media: cec-pin.c: use proper ktime accessor functions Use ktime_to_ns/ns_to_ktime. This makes it possible to work with older kernels and the media_build compatibility system. For the mainline kernel these functions are NOPs. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Hans Verkuil <hansverk@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-01 16:37:54 +08:00
hrtimer_start(&pin->timer, ns_to_ktime(0),
HRTIMER_MODE_REL);
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
} else {
if (pin->ops->disable_irq)
pin->ops->disable_irq(adap);
hrtimer_cancel(&pin->timer);
kthread_stop(pin->kthread);
cec_pin_read(pin);
cec_pin_to_idle(pin);
pin->state = CEC_ST_OFF;
}
return 0;
}
static int cec_pin_adap_log_addr(struct cec_adapter *adap, u8 log_addr)
{
struct cec_pin *pin = adap->pin;
if (log_addr == CEC_LOG_ADDR_INVALID)
pin->la_mask = 0;
else
pin->la_mask |= (1 << log_addr);
return 0;
}
media: cec-pin: create cec_pin_start_timer() function This function will be needed for injecting a custom pulse. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
void cec_pin_start_timer(struct cec_pin *pin)
{
if (pin->state != CEC_ST_RX_IRQ)
return;
atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_UNCHANGED);
pin->ops->disable_irq(pin->adap);
cec_pin_high(pin);
cec_pin_to_idle(pin);
hrtimer_start(&pin->timer, ns_to_ktime(0), HRTIMER_MODE_REL);
}
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
static int cec_pin_adap_transmit(struct cec_adapter *adap, u8 attempts,
u32 signal_free_time, struct cec_msg *msg)
{
struct cec_pin *pin = adap->pin;
media: cec-gpio: select correct Signal Free Time If a receive is in progress or starts before the transmit has a chance, then lower the Signal Free Time of the upcoming transmit to no more than CEC_SIGNAL_FREE_TIME_NEW_INITIATOR. This is per the specification requirements. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-10-05 20:51:45 +08:00
/*
* If a receive is in progress, then this transmit should use
* a signal free time of max CEC_SIGNAL_FREE_TIME_NEW_INITIATOR
* since when it starts transmitting it will have a new initiator.
*/
if (pin->state != CEC_ST_IDLE &&
signal_free_time > CEC_SIGNAL_FREE_TIME_NEW_INITIATOR)
signal_free_time = CEC_SIGNAL_FREE_TIME_NEW_INITIATOR;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->tx_signal_free_time = signal_free_time;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
pin->tx_extra_bytes = 0;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->tx_msg = *msg;
media: cec-pin: add error injection support Implement all the error injection commands. The state machine gets new states for the various error situations, helper functions are added to detect whether an error injection is active and the actual error injections are implemented. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
if (msg->len > 1) {
/* Error injection: add byte to the message */
pin->tx_extra_bytes = tx_add_bytes(pin);
}
if (msg->len > 2 && tx_remove_byte(pin)) {
/* Error injection: remove byte from the message */
pin->tx_msg.len--;
}
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->work_tx_status = 0;
pin->tx_bit = 0;
media: cec-pin: create cec_pin_start_timer() function This function will be needed for injecting a custom pulse. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
cec_pin_start_timer(pin);
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
return 0;
}
static void cec_pin_adap_status(struct cec_adapter *adap,
struct seq_file *file)
{
struct cec_pin *pin = adap->pin;
media: cec-pin: improve status log Keep track of the number of short or long start bits, the number of short or long data bits and the number of initiated or detected low drive conditions. Show this information in the status debugfs log. Helpful when debugging, particularly when doing error injection as well. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-01 15:02:24 +08:00
seq_printf(file, "state: %s\n", states[pin->state].name);
seq_printf(file, "tx_bit: %d\n", pin->tx_bit);
seq_printf(file, "rx_bit: %d\n", pin->rx_bit);
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
seq_printf(file, "cec pin: %d\n", pin->ops->read(adap));
media: cec: improve CEC pin event handling It turns out that the struct cec_fh event buffer size of 64 events (64 for CEC_EVENT_PIN_CEC_LOW and 64 for _HIGH) is too small. It's about 160 ms worth of events and if the Raspberry Pi is busy, then it might take too long for the application to be scheduled so that it can drain the pending events. Increase these buffers to 800 events which is at least 2 seconds worth of events. There is also a FIFO in between the interrupt and the cec-pin thread. The thread passes the events on to the CEC core. It is important that should this FIFO fill up the cec core will be informed that events have been lost so this can be communicated to the user by setting CEC_EVENT_FL_DROPPED_EVENTS. It is very hard to debug CEC problems if events were lost without informing the user of that fact. If events were dropped due to the FIFO filling up, then the debugfs status file will let you know how many events were dropped. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-07 05:20:00 +08:00
seq_printf(file, "cec pin events dropped: %u\n",
pin->work_pin_events_dropped_cnt);
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
seq_printf(file, "irq failed: %d\n", pin->enable_irq_failed);
if (pin->timer_100ms_overruns) {
seq_printf(file, "timer overruns > 100ms: %u of %u\n",
pin->timer_100ms_overruns, pin->timer_cnt);
seq_printf(file, "timer overruns > 300ms: %u of %u\n",
pin->timer_300ms_overruns, pin->timer_cnt);
seq_printf(file, "max timer overrun: %u usecs\n",
pin->timer_max_overrun);
seq_printf(file, "avg timer overrun: %u usecs\n",
pin->timer_sum_overrun / pin->timer_100ms_overruns);
}
media: cec-pin: improve status log Keep track of the number of short or long start bits, the number of short or long data bits and the number of initiated or detected low drive conditions. Show this information in the status debugfs log. Helpful when debugging, particularly when doing error injection as well. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-01 15:02:24 +08:00
if (pin->rx_start_bit_low_too_short_cnt)
seq_printf(file,
"rx start bit low too short: %u (delta %u, ts %llu)\n",
pin->rx_start_bit_low_too_short_cnt,
pin->rx_start_bit_low_too_short_delta,
pin->rx_start_bit_low_too_short_ts);
if (pin->rx_start_bit_too_short_cnt)
seq_printf(file,
"rx start bit too short: %u (delta %u, ts %llu)\n",
pin->rx_start_bit_too_short_cnt,
pin->rx_start_bit_too_short_delta,
pin->rx_start_bit_too_short_ts);
if (pin->rx_start_bit_too_long_cnt)
seq_printf(file, "rx start bit too long: %u\n",
pin->rx_start_bit_too_long_cnt);
if (pin->rx_data_bit_too_short_cnt)
seq_printf(file,
"rx data bit too short: %u (delta %u, ts %llu)\n",
pin->rx_data_bit_too_short_cnt,
pin->rx_data_bit_too_short_delta,
pin->rx_data_bit_too_short_ts);
if (pin->rx_data_bit_too_long_cnt)
seq_printf(file, "rx data bit too long: %u\n",
pin->rx_data_bit_too_long_cnt);
seq_printf(file, "rx initiated low drive: %u\n", pin->rx_low_drive_cnt);
seq_printf(file, "tx detected low drive: %u\n", pin->tx_low_drive_cnt);
media: cec: improve CEC pin event handling It turns out that the struct cec_fh event buffer size of 64 events (64 for CEC_EVENT_PIN_CEC_LOW and 64 for _HIGH) is too small. It's about 160 ms worth of events and if the Raspberry Pi is busy, then it might take too long for the application to be scheduled so that it can drain the pending events. Increase these buffers to 800 events which is at least 2 seconds worth of events. There is also a FIFO in between the interrupt and the cec-pin thread. The thread passes the events on to the CEC core. It is important that should this FIFO fill up the cec core will be informed that events have been lost so this can be communicated to the user by setting CEC_EVENT_FL_DROPPED_EVENTS. It is very hard to debug CEC problems if events were lost without informing the user of that fact. If events were dropped due to the FIFO filling up, then the debugfs status file will let you know how many events were dropped. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-07 05:20:00 +08:00
pin->work_pin_events_dropped_cnt = 0;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
pin->timer_cnt = 0;
pin->timer_100ms_overruns = 0;
pin->timer_300ms_overruns = 0;
pin->timer_max_overrun = 0;
pin->timer_sum_overrun = 0;
media: cec-pin: improve status log Keep track of the number of short or long start bits, the number of short or long data bits and the number of initiated or detected low drive conditions. Show this information in the status debugfs log. Helpful when debugging, particularly when doing error injection as well. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-01 15:02:24 +08:00
pin->rx_start_bit_low_too_short_cnt = 0;
pin->rx_start_bit_too_short_cnt = 0;
pin->rx_start_bit_too_long_cnt = 0;
pin->rx_data_bit_too_short_cnt = 0;
pin->rx_data_bit_too_long_cnt = 0;
pin->rx_low_drive_cnt = 0;
pin->tx_low_drive_cnt = 0;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
if (pin->ops->status)
pin->ops->status(adap, file);
}
static int cec_pin_adap_monitor_all_enable(struct cec_adapter *adap,
bool enable)
{
struct cec_pin *pin = adap->pin;
pin->monitor_all = enable;
return 0;
}
static void cec_pin_adap_free(struct cec_adapter *adap)
{
struct cec_pin *pin = adap->pin;
if (pin->ops->free)
pin->ops->free(adap);
adap->pin = NULL;
kfree(pin);
}
media: cec-pin: add 'received' callback Drivers that use the CEC pin framework have no way of processing messages themselves by providing the 'received' callback. This is present in cec_ops, but not in cec_pin_ops. Add support for this callback. Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-10-09 22:49:19 +08:00
static int cec_pin_received(struct cec_adapter *adap, struct cec_msg *msg)
{
struct cec_pin *pin = adap->pin;
if (pin->ops->received)
return pin->ops->received(adap, msg);
return -ENOMSG;
}
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
void cec_pin_changed(struct cec_adapter *adap, bool value)
{
struct cec_pin *pin = adap->pin;
cec_pin_update(pin, value, false);
if (!value && (adap->is_configuring || adap->is_configured ||
media: cec-pin: fix irq handling The free_irq() function could be called from interrupt context, which is invalid. Move this to the thread. In the interrupt handler we just request that the thread disables the irq. This is done through an atomic so we don't need to add any spinlocks. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-08-16 15:13:02 +08:00
adap->monitor_all_cnt))
atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_DISABLE);
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
}
EXPORT_SYMBOL_GPL(cec_pin_changed);
static const struct cec_adap_ops cec_pin_adap_ops = {
.adap_enable = cec_pin_adap_enable,
.adap_monitor_all_enable = cec_pin_adap_monitor_all_enable,
.adap_log_addr = cec_pin_adap_log_addr,
.adap_transmit = cec_pin_adap_transmit,
.adap_status = cec_pin_adap_status,
.adap_free = cec_pin_adap_free,
media: cec-pin-error-inj: parse/show error injection Add support to the CEC Pin framework to parse error injection commands and to show them. The next patch will do the actual implementation of this. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
#ifdef CONFIG_CEC_PIN_ERROR_INJ
.error_inj_parse_line = cec_pin_error_inj_parse_line,
.error_inj_show = cec_pin_error_inj_show,
#endif
media: cec-pin: add 'received' callback Drivers that use the CEC pin framework have no way of processing messages themselves by providing the 'received' callback. This is present in cec_ops, but not in cec_pin_ops. Add support for this callback. Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-10-09 22:49:19 +08:00
.received = cec_pin_received,
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
};
struct cec_adapter *cec_pin_allocate_adapter(const struct cec_pin_ops *pin_ops,
void *priv, const char *name, u32 caps)
{
struct cec_adapter *adap;
struct cec_pin *pin = kzalloc(sizeof(*pin), GFP_KERNEL);
if (pin == NULL)
return ERR_PTR(-ENOMEM);
pin->ops = pin_ops;
hrtimer_init(&pin->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
pin->timer.function = cec_pin_timer;
init_waitqueue_head(&pin->kthread_waitq);
media: cec-pin-error-inj: parse/show error injection Add support to the CEC Pin framework to parse error injection commands and to show them. The next patch will do the actual implementation of this. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 21:55:09 +08:00
pin->tx_custom_low_usecs = CEC_TIM_CUSTOM_DEFAULT;
pin->tx_custom_high_usecs = CEC_TIM_CUSTOM_DEFAULT;
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
adap = cec_allocate_adapter(&cec_pin_adap_ops, priv, name,
caps | CEC_CAP_MONITOR_ALL | CEC_CAP_MONITOR_PIN,
CEC_MAX_LOG_ADDRS);
media: cec-pin: use IS_ERR instead of PTR_ERR_OR_ZERO cec_allocate_adapter never returns NULL, so just use IS_ERR instead of PTR_ERR_OR_ZERO. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-18 16:11:46 +08:00
if (IS_ERR(adap)) {
media: cec-pin: add low-level pin hardware support Add support for CEC hardware that relies on low-level pin polling or GPIO interrupts. One example is the Allwinner SoC. But any GPIO-based CEC implementation can use this as well. A GPIO implementation is very suitable as well for debugging: it can use interrupts to detect state changes and report it. Userspace can then verify if the bus traffic is correct. This also makes error injection possible. The disadvantage is that it is hard to get the timings right since linux isn't a hard realtime system. In general on an idle system it works quite well, but under load the timer will miss its mark every so often. The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics with respect to the timer overruns. When the adapter is unconfigured and the low-level driver supports interrupts, then the interrupt will be used to detect changes. This should be quite accurate. But when the adapter is configured a hrtimer has to be used. The hrtimer implements a state machine where for each state the code will read the bus or drive the bus and go on to the next state. It will re-arm the timer with a delay based on the next state. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-11 14:30:42 +08:00
kfree(pin);
return adap;
}
adap->pin = pin;
pin->adap = adap;
cec_pin_update(pin, cec_pin_high(pin), true);
return adap;
}
EXPORT_SYMBOL_GPL(cec_pin_allocate_adapter);