linux/drivers/gpu/drm/i2c/tda9950.c

511 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* TDA9950 Consumer Electronics Control driver
*
* The NXP TDA9950 implements the HDMI Consumer Electronics Control
* interface. The host interface is similar to a mailbox: the data
* registers starting at REG_CDR0 are written to send a command to the
* internal CPU, and replies are read from these registers.
*
* As the data registers represent a mailbox, they must be accessed
* as a single I2C transaction. See the TDA9950 data sheet for details.
*/
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/platform_data/tda9950.h>
#include <linux/slab.h>
#include <drm/drm_edid.h>
#include <media/cec.h>
#include <media/cec-notifier.h>
enum {
REG_CSR = 0x00,
CSR_BUSY = BIT(7),
CSR_INT = BIT(6),
CSR_ERR = BIT(5),
REG_CER = 0x01,
REG_CVR = 0x02,
REG_CCR = 0x03,
CCR_RESET = BIT(7),
CCR_ON = BIT(6),
REG_ACKH = 0x04,
REG_ACKL = 0x05,
REG_CCONR = 0x06,
CCONR_ENABLE_ERROR = BIT(4),
CCONR_RETRY_MASK = 7,
REG_CDR0 = 0x07,
CDR1_REQ = 0x00,
CDR1_CNF = 0x01,
CDR1_IND = 0x81,
CDR1_ERR = 0x82,
CDR1_IER = 0x83,
CDR2_CNF_SUCCESS = 0x00,
CDR2_CNF_OFF_STATE = 0x80,
CDR2_CNF_BAD_REQ = 0x81,
CDR2_CNF_CEC_ACCESS = 0x82,
CDR2_CNF_ARB_ERROR = 0x83,
CDR2_CNF_BAD_TIMING = 0x84,
CDR2_CNF_NACK_ADDR = 0x85,
CDR2_CNF_NACK_DATA = 0x86,
};
struct tda9950_priv {
struct i2c_client *client;
struct device *hdmi;
struct cec_adapter *adap;
struct tda9950_glue *glue;
u16 addresses;
struct cec_msg rx_msg;
struct cec_notifier *notify;
bool open;
};
static int tda9950_write_range(struct i2c_client *client, u8 addr, u8 *p, int cnt)
{
struct i2c_msg msg;
u8 buf[CEC_MAX_MSG_SIZE + 3];
int ret;
if (WARN_ON(cnt > sizeof(buf) - 1))
return -EINVAL;
buf[0] = addr;
memcpy(buf + 1, p, cnt);
msg.addr = client->addr;
msg.flags = 0;
msg.len = cnt + 1;
msg.buf = buf;
dev_dbg(&client->dev, "wr 0x%02x: %*ph\n", addr, cnt, p);
ret = i2c_transfer(client->adapter, &msg, 1);
if (ret < 0)
dev_err(&client->dev, "Error %d writing to cec:0x%x\n", ret, addr);
return ret < 0 ? ret : 0;
}
static void tda9950_write(struct i2c_client *client, u8 addr, u8 val)
{
tda9950_write_range(client, addr, &val, 1);
}
static int tda9950_read_range(struct i2c_client *client, u8 addr, u8 *p, int cnt)
{
struct i2c_msg msg[2];
int ret;
msg[0].addr = client->addr;
msg[0].flags = 0;
msg[0].len = 1;
msg[0].buf = &addr;
msg[1].addr = client->addr;
msg[1].flags = I2C_M_RD;
msg[1].len = cnt;
msg[1].buf = p;
ret = i2c_transfer(client->adapter, msg, 2);
if (ret < 0)
dev_err(&client->dev, "Error %d reading from cec:0x%x\n", ret, addr);
dev_dbg(&client->dev, "rd 0x%02x: %*ph\n", addr, cnt, p);
return ret;
}
static u8 tda9950_read(struct i2c_client *client, u8 addr)
{
int ret;
u8 val;
ret = tda9950_read_range(client, addr, &val, 1);
if (ret < 0)
val = 0;
return val;
}
static irqreturn_t tda9950_irq(int irq, void *data)
{
struct tda9950_priv *priv = data;
unsigned int tx_status;
u8 csr, cconr, buf[19];
u8 arb_lost_cnt, nack_cnt, err_cnt;
if (!priv->open)
return IRQ_NONE;
csr = tda9950_read(priv->client, REG_CSR);
if (!(csr & CSR_INT))
return IRQ_NONE;
cconr = tda9950_read(priv->client, REG_CCONR) & CCONR_RETRY_MASK;
tda9950_read_range(priv->client, REG_CDR0, buf, sizeof(buf));
/*
* This should never happen: the data sheet says that there will
* always be a valid message if the interrupt line is asserted.
*/
if (buf[0] == 0) {
dev_warn(&priv->client->dev, "interrupt pending, but no message?\n");
return IRQ_NONE;
}
switch (buf[1]) {
case CDR1_CNF: /* transmit result */
arb_lost_cnt = nack_cnt = err_cnt = 0;
switch (buf[2]) {
case CDR2_CNF_SUCCESS:
tx_status = CEC_TX_STATUS_OK;
break;
case CDR2_CNF_ARB_ERROR:
tx_status = CEC_TX_STATUS_ARB_LOST;
arb_lost_cnt = cconr;
break;
case CDR2_CNF_NACK_ADDR:
tx_status = CEC_TX_STATUS_NACK;
nack_cnt = cconr;
break;
default: /* some other error, refer to TDA9950 docs */
dev_err(&priv->client->dev, "CNF reply error 0x%02x\n",
buf[2]);
tx_status = CEC_TX_STATUS_ERROR;
err_cnt = cconr;
break;
}
/* TDA9950 executes all retries for us */
if (tx_status != CEC_TX_STATUS_OK)
tx_status |= CEC_TX_STATUS_MAX_RETRIES;
cec_transmit_done(priv->adap, tx_status, arb_lost_cnt,
nack_cnt, 0, err_cnt);
break;
case CDR1_IND:
priv->rx_msg.len = buf[0] - 2;
if (priv->rx_msg.len > CEC_MAX_MSG_SIZE)
priv->rx_msg.len = CEC_MAX_MSG_SIZE;
memcpy(priv->rx_msg.msg, buf + 2, priv->rx_msg.len);
cec_received_msg(priv->adap, &priv->rx_msg);
break;
default: /* unknown */
dev_err(&priv->client->dev, "unknown service id 0x%02x\n",
buf[1]);
break;
}
return IRQ_HANDLED;
}
static int tda9950_cec_transmit(struct cec_adapter *adap, u8 attempts,
u32 signal_free_time, struct cec_msg *msg)
{
struct tda9950_priv *priv = adap->priv;
u8 buf[CEC_MAX_MSG_SIZE + 2];
buf[0] = 2 + msg->len;
buf[1] = CDR1_REQ;
memcpy(buf + 2, msg->msg, msg->len);
if (attempts > 5)
attempts = 5;
tda9950_write(priv->client, REG_CCONR, attempts);
return tda9950_write_range(priv->client, REG_CDR0, buf, 2 + msg->len);
}
static int tda9950_cec_adap_log_addr(struct cec_adapter *adap, u8 addr)
{
struct tda9950_priv *priv = adap->priv;
u16 addresses;
u8 buf[2];
if (addr == CEC_LOG_ADDR_INVALID)
addresses = priv->addresses = 0;
else
addresses = priv->addresses |= BIT(addr);
/* TDA9950 doesn't want address 15 set */
addresses &= 0x7fff;
buf[0] = addresses >> 8;
buf[1] = addresses;
return tda9950_write_range(priv->client, REG_ACKH, buf, 2);
}
/*
* When operating as part of the TDA998x, we need additional handling
* to initialise and shut down the TDA9950 part of the device. These
* two hooks are provided to allow the TDA998x code to perform those
* activities.
*/
static int tda9950_glue_open(struct tda9950_priv *priv)
{
int ret = 0;
if (priv->glue && priv->glue->open)
ret = priv->glue->open(priv->glue->data);
priv->open = true;
return ret;
}
static void tda9950_glue_release(struct tda9950_priv *priv)
{
priv->open = false;
if (priv->glue && priv->glue->release)
priv->glue->release(priv->glue->data);
}
static int tda9950_open(struct tda9950_priv *priv)
{
struct i2c_client *client = priv->client;
int ret;
ret = tda9950_glue_open(priv);
if (ret)
return ret;
/* Reset the TDA9950, and wait 250ms for it to recover */
tda9950_write(client, REG_CCR, CCR_RESET);
msleep(250);
tda9950_cec_adap_log_addr(priv->adap, CEC_LOG_ADDR_INVALID);
/* Start the command processor */
tda9950_write(client, REG_CCR, CCR_ON);
return 0;
}
static void tda9950_release(struct tda9950_priv *priv)
{
struct i2c_client *client = priv->client;
int timeout = 50;
u8 csr;
/* Stop the command processor */
tda9950_write(client, REG_CCR, 0);
/* Wait up to .5s for it to signal non-busy */
do {
csr = tda9950_read(client, REG_CSR);
if (!(csr & CSR_BUSY) || !--timeout)
break;
msleep(10);
} while (1);
/* Warn the user that their IRQ may die if it's shared. */
if (csr & CSR_BUSY)
dev_warn(&client->dev, "command processor failed to stop, irq%d may die (csr=0x%02x)\n",
client->irq, csr);
tda9950_glue_release(priv);
}
static int tda9950_cec_adap_enable(struct cec_adapter *adap, bool enable)
{
struct tda9950_priv *priv = adap->priv;
if (!enable) {
tda9950_release(priv);
return 0;
} else {
return tda9950_open(priv);
}
}
static const struct cec_adap_ops tda9950_cec_ops = {
.adap_enable = tda9950_cec_adap_enable,
.adap_log_addr = tda9950_cec_adap_log_addr,
.adap_transmit = tda9950_cec_transmit,
};
/*
* When operating as part of the TDA998x, we need to claim additional
* resources. These two hooks permit the management of those resources.
*/
static void tda9950_devm_glue_exit(void *data)
{
struct tda9950_glue *glue = data;
if (glue && glue->exit)
glue->exit(glue->data);
}
static int tda9950_devm_glue_init(struct device *dev, struct tda9950_glue *glue)
{
int ret;
if (glue && glue->init) {
ret = glue->init(glue->data);
if (ret)
return ret;
}
ret = devm_add_action(dev, tda9950_devm_glue_exit, glue);
if (ret)
tda9950_devm_glue_exit(glue);
return ret;
}
static void tda9950_cec_del(void *data)
{
struct tda9950_priv *priv = data;
cec_delete_adapter(priv->adap);
}
static int tda9950_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct tda9950_glue *glue = client->dev.platform_data;
struct device *dev = &client->dev;
struct tda9950_priv *priv;
unsigned long irqflags;
int ret;
u8 cvr;
/*
* We must have I2C functionality: our multi-byte accesses
* must be performed as a single contiguous transaction.
*/
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
dev_err(&client->dev,
"adapter does not support I2C functionality\n");
return -ENXIO;
}
/* We must have an interrupt to be functional. */
if (client->irq <= 0) {
dev_err(&client->dev, "driver requires an interrupt\n");
return -ENXIO;
}
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->client = client;
priv->glue = glue;
i2c_set_clientdata(client, priv);
/*
* If we're part of a TDA998x, we want the class devices to be
* associated with the HDMI Tx so we have a tight relationship
* between the HDMI interface and the CEC interface.
*/
priv->hdmi = dev;
if (glue && glue->parent)
priv->hdmi = glue->parent;
priv->adap = cec_allocate_adapter(&tda9950_cec_ops, priv, "tda9950",
CEC_CAP_DEFAULTS |
CEC_CAP_CONNECTOR_INFO,
CEC_MAX_LOG_ADDRS);
if (IS_ERR(priv->adap))
return PTR_ERR(priv->adap);
ret = devm_add_action(dev, tda9950_cec_del, priv);
if (ret) {
cec_delete_adapter(priv->adap);
return ret;
}
ret = tda9950_devm_glue_init(dev, glue);
if (ret)
return ret;
ret = tda9950_glue_open(priv);
if (ret)
return ret;
cvr = tda9950_read(client, REG_CVR);
dev_info(&client->dev,
"TDA9950 CEC interface, hardware version %u.%u\n",
cvr >> 4, cvr & 15);
tda9950_glue_release(priv);
irqflags = IRQF_TRIGGER_FALLING;
if (glue)
irqflags = glue->irq_flags;
ret = devm_request_threaded_irq(dev, client->irq, NULL, tda9950_irq,
irqflags | IRQF_SHARED | IRQF_ONESHOT,
dev_name(&client->dev), priv);
if (ret < 0)
return ret;
priv->notify = cec_notifier_cec_adap_register(priv->hdmi, NULL,
priv->adap);
if (!priv->notify)
return -ENOMEM;
ret = cec_register_adapter(priv->adap, priv->hdmi);
if (ret < 0) {
cec_notifier_cec_adap_unregister(priv->notify, priv->adap);
return ret;
}
/*
* CEC documentation says we must not call cec_delete_adapter
* after a successful call to cec_register_adapter().
*/
devm_remove_action(dev, tda9950_cec_del, priv);
return 0;
}
static int tda9950_remove(struct i2c_client *client)
{
struct tda9950_priv *priv = i2c_get_clientdata(client);
cec_notifier_cec_adap_unregister(priv->notify, priv->adap);
cec_unregister_adapter(priv->adap);
return 0;
}
static struct i2c_device_id tda9950_ids[] = {
{ "tda9950", 0 },
{ },
};
MODULE_DEVICE_TABLE(i2c, tda9950_ids);
static struct i2c_driver tda9950_driver = {
.probe = tda9950_probe,
.remove = tda9950_remove,
.driver = {
.name = "tda9950",
},
.id_table = tda9950_ids,
};
module_i2c_driver(tda9950_driver);
MODULE_AUTHOR("Russell King <rmk+kernel@armlinux.org.uk>");
MODULE_DESCRIPTION("TDA9950/TDA998x Consumer Electronics Control Driver");
MODULE_LICENSE("GPL v2");