linux/drivers/i2c/busses/i2c-designware-master.c

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/*
* Synopsys DesignWare I2C adapter driver (master only).
*
* Based on the TI DAVINCI I2C adapter driver.
*
* Copyright (C) 2006 Texas Instruments.
* Copyright (C) 2007 MontaVista Software Inc.
* Copyright (C) 2009 Provigent Ltd.
*
* ----------------------------------------------------------------------------
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* ----------------------------------------------------------------------------
*
*/
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>
#include "i2c-designware-core.h"
static void i2c_dw_configure_fifo_master(struct dw_i2c_dev *dev)
{
/* Configure Tx/Rx FIFO threshold levels */
dw_writel(dev, dev->tx_fifo_depth / 2, DW_IC_TX_TL);
dw_writel(dev, 0, DW_IC_RX_TL);
/* Configure the I2C master */
dw_writel(dev, dev->master_cfg, DW_IC_CON);
}
/**
* i2c_dw_init() - Initialize the designware I2C master hardware
* @dev: device private data
*
* This functions configures and enables the I2C master.
* This function is called during I2C init function, and in case of timeout at
* run time.
*/
static int i2c_dw_init_master(struct dw_i2c_dev *dev)
{
u32 hcnt, lcnt;
u32 reg, comp_param1;
u32 sda_falling_time, scl_falling_time;
int ret;
ret = i2c_dw_acquire_lock(dev);
if (ret)
return ret;
reg = dw_readl(dev, DW_IC_COMP_TYPE);
if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
/* Configure register endianess access */
dev->flags |= ACCESS_SWAP;
} else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
/* Configure register access mode 16bit */
dev->flags |= ACCESS_16BIT;
} else if (reg != DW_IC_COMP_TYPE_VALUE) {
dev_err(dev->dev,
"Unknown Synopsys component type: 0x%08x\n", reg);
i2c_dw_release_lock(dev);
return -ENODEV;
}
comp_param1 = dw_readl(dev, DW_IC_COMP_PARAM_1);
/* Disable the adapter */
__i2c_dw_enable_and_wait(dev, false);
/* Set standard and fast speed deviders for high/low periods */
i2c-designware: Improved _HCNT/_LCNT calculation * Calculate with accurate conditional expressions from DW manuals. * Round ic_clk by adding 0.5 as it's important at high ic_clk rate. * Take into account "tHD;STA" issue for _HCNT calculation. * Take into account "tf" for _LCNT calculation. * Add "cond" and "offset" fot further correction requirements. For _HCNT calculation, there's one issue needs to be carefully considered; DesignWare I2C core doesn't seem to have solid strategy to meet the tHD;STA timing spec. If you configure _HCNT based on the tHIGH timing spec, it easily results in violation of the tHD;STA spec. After many trials, we came to the conclusion that the tHD;STA period is proportional to (_HCNT + 3). For the safety's sake, this should be selected by default. As for _LCNT calculation, DW I2C core has one characteristic behavior; he starts counting the SCL CNTs for the LOW period of the SCL clock (tLOW) as soon as it pulls the SCL line. At that time, he doesn't take into account the fall time of SCL signal (tf), IOW, he starts counting CNTs without confirming the SCL input voltage has dropped to below VIL. This characteristics becomes a problem on some platforms where tf is considerably long, and results in violation of the tLOW timing spec. To make the driver configurable as much as possible for various cases, we'd have separated arguments "tf" and "offset", and for safety default values should be 0.3 us and 0, respectively. Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com> Acked-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2009-11-06 20:47:01 +08:00
sda_falling_time = dev->sda_falling_time ?: 300; /* ns */
scl_falling_time = dev->scl_falling_time ?: 300; /* ns */
/* Set SCL timing parameters for standard-mode */
if (dev->ss_hcnt && dev->ss_lcnt) {
hcnt = dev->ss_hcnt;
lcnt = dev->ss_lcnt;
} else {
hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev),
4000, /* tHD;STA = tHIGH = 4.0 us */
sda_falling_time,
0, /* 0: DW default, 1: Ideal */
0); /* No offset */
lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev),
4700, /* tLOW = 4.7 us */
scl_falling_time,
0); /* No offset */
}
dw_writel(dev, hcnt, DW_IC_SS_SCL_HCNT);
dw_writel(dev, lcnt, DW_IC_SS_SCL_LCNT);
i2c-designware: Improved _HCNT/_LCNT calculation * Calculate with accurate conditional expressions from DW manuals. * Round ic_clk by adding 0.5 as it's important at high ic_clk rate. * Take into account "tHD;STA" issue for _HCNT calculation. * Take into account "tf" for _LCNT calculation. * Add "cond" and "offset" fot further correction requirements. For _HCNT calculation, there's one issue needs to be carefully considered; DesignWare I2C core doesn't seem to have solid strategy to meet the tHD;STA timing spec. If you configure _HCNT based on the tHIGH timing spec, it easily results in violation of the tHD;STA spec. After many trials, we came to the conclusion that the tHD;STA period is proportional to (_HCNT + 3). For the safety's sake, this should be selected by default. As for _LCNT calculation, DW I2C core has one characteristic behavior; he starts counting the SCL CNTs for the LOW period of the SCL clock (tLOW) as soon as it pulls the SCL line. At that time, he doesn't take into account the fall time of SCL signal (tf), IOW, he starts counting CNTs without confirming the SCL input voltage has dropped to below VIL. This characteristics becomes a problem on some platforms where tf is considerably long, and results in violation of the tLOW timing spec. To make the driver configurable as much as possible for various cases, we'd have separated arguments "tf" and "offset", and for safety default values should be 0.3 us and 0, respectively. Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com> Acked-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2009-11-06 20:47:01 +08:00
dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
/* Set SCL timing parameters for fast-mode or fast-mode plus */
if ((dev->clk_freq == 1000000) && dev->fp_hcnt && dev->fp_lcnt) {
hcnt = dev->fp_hcnt;
lcnt = dev->fp_lcnt;
} else if (dev->fs_hcnt && dev->fs_lcnt) {
hcnt = dev->fs_hcnt;
lcnt = dev->fs_lcnt;
} else {
hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev),
600, /* tHD;STA = tHIGH = 0.6 us */
sda_falling_time,
0, /* 0: DW default, 1: Ideal */
0); /* No offset */
lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev),
1300, /* tLOW = 1.3 us */
scl_falling_time,
0); /* No offset */
}
dw_writel(dev, hcnt, DW_IC_FS_SCL_HCNT);
dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT);
i2c-designware: Improved _HCNT/_LCNT calculation * Calculate with accurate conditional expressions from DW manuals. * Round ic_clk by adding 0.5 as it's important at high ic_clk rate. * Take into account "tHD;STA" issue for _HCNT calculation. * Take into account "tf" for _LCNT calculation. * Add "cond" and "offset" fot further correction requirements. For _HCNT calculation, there's one issue needs to be carefully considered; DesignWare I2C core doesn't seem to have solid strategy to meet the tHD;STA timing spec. If you configure _HCNT based on the tHIGH timing spec, it easily results in violation of the tHD;STA spec. After many trials, we came to the conclusion that the tHD;STA period is proportional to (_HCNT + 3). For the safety's sake, this should be selected by default. As for _LCNT calculation, DW I2C core has one characteristic behavior; he starts counting the SCL CNTs for the LOW period of the SCL clock (tLOW) as soon as it pulls the SCL line. At that time, he doesn't take into account the fall time of SCL signal (tf), IOW, he starts counting CNTs without confirming the SCL input voltage has dropped to below VIL. This characteristics becomes a problem on some platforms where tf is considerably long, and results in violation of the tLOW timing spec. To make the driver configurable as much as possible for various cases, we'd have separated arguments "tf" and "offset", and for safety default values should be 0.3 us and 0, respectively. Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com> Acked-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2009-11-06 20:47:01 +08:00
dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
if ((dev->master_cfg & DW_IC_CON_SPEED_MASK) ==
DW_IC_CON_SPEED_HIGH) {
if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK)
!= DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH) {
dev_err(dev->dev, "High Speed not supported!\n");
dev->master_cfg &= ~DW_IC_CON_SPEED_MASK;
dev->master_cfg |= DW_IC_CON_SPEED_FAST;
} else if (dev->hs_hcnt && dev->hs_lcnt) {
hcnt = dev->hs_hcnt;
lcnt = dev->hs_lcnt;
dw_writel(dev, hcnt, DW_IC_HS_SCL_HCNT);
dw_writel(dev, lcnt, DW_IC_HS_SCL_LCNT);
dev_dbg(dev->dev, "HighSpeed-mode HCNT:LCNT = %d:%d\n",
hcnt, lcnt);
}
}
/* Configure SDA Hold Time if required */
reg = dw_readl(dev, DW_IC_COMP_VERSION);
if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
if (!dev->sda_hold_time) {
/* Keep previous hold time setting if no one set it */
dev->sda_hold_time = dw_readl(dev, DW_IC_SDA_HOLD);
}
/*
* Workaround for avoiding TX arbitration lost in case I2C
* slave pulls SDA down "too quickly" after falling egde of
* SCL by enabling non-zero SDA RX hold. Specification says it
* extends incoming SDA low to high transition while SCL is
* high but it apprears to help also above issue.
*/
if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK))
dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT;
dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
} else if (dev->sda_hold_time) {
dev_warn(dev->dev,
"Hardware too old to adjust SDA hold time.\n");
}
i2c_dw_configure_fifo_master(dev);
i2c_dw_release_lock(dev);
return 0;
}
static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
{
struct i2c_msg *msgs = dev->msgs;
u32 ic_con, ic_tar = 0;
/* Disable the adapter */
__i2c_dw_enable_and_wait(dev, false);
/* If the slave address is ten bit address, enable 10BITADDR */
ic_con = dw_readl(dev, DW_IC_CON);
if (msgs[dev->msg_write_idx].flags & I2C_M_TEN) {
ic_con |= DW_IC_CON_10BITADDR_MASTER;
/*
* If I2C_DYNAMIC_TAR_UPDATE is set, the 10-bit addressing
* mode has to be enabled via bit 12 of IC_TAR register.
* We set it always as I2C_DYNAMIC_TAR_UPDATE can't be
* detected from registers.
*/
ic_tar = DW_IC_TAR_10BITADDR_MASTER;
} else {
ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
}
dw_writel(dev, ic_con, DW_IC_CON);
/*
* Set the slave (target) address and enable 10-bit addressing mode
* if applicable.
*/
dw_writel(dev, msgs[dev->msg_write_idx].addr | ic_tar, DW_IC_TAR);
/* Enforce disabled interrupts (due to HW issues) */
2014-04-11 07:03:19 +08:00
i2c_dw_disable_int(dev);
/* Enable the adapter */
__i2c_dw_enable(dev, true);
/* Dummy read to avoid the register getting stuck on Bay Trail */
dw_readl(dev, DW_IC_ENABLE_STATUS);
/* Clear and enable interrupts */
dw_readl(dev, DW_IC_CLR_INTR);
dw_writel(dev, DW_IC_INTR_MASTER_MASK, DW_IC_INTR_MASK);
}
/*
* Initiate (and continue) low level master read/write transaction.
* This function is only called from i2c_dw_isr, and pumping i2c_msg
* messages into the tx buffer. Even if the size of i2c_msg data is
* longer than the size of the tx buffer, it handles everything.
*/
static void
i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
{
struct i2c_msg *msgs = dev->msgs;
u32 intr_mask;
int tx_limit, rx_limit;
u32 addr = msgs[dev->msg_write_idx].addr;
u32 buf_len = dev->tx_buf_len;
u8 *buf = dev->tx_buf;
bool need_restart = false;
intr_mask = DW_IC_INTR_MASTER_MASK;
for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) {
u32 flags = msgs[dev->msg_write_idx].flags;
/*
* If target address has changed, we need to
* reprogram the target address in the I2C
* adapter when we are done with this transfer.
*/
if (msgs[dev->msg_write_idx].addr != addr) {
dev_err(dev->dev,
"%s: invalid target address\n", __func__);
dev->msg_err = -EINVAL;
break;
}
if (msgs[dev->msg_write_idx].len == 0) {
dev_err(dev->dev,
"%s: invalid message length\n", __func__);
dev->msg_err = -EINVAL;
break;
}
if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
/* new i2c_msg */
buf = msgs[dev->msg_write_idx].buf;
buf_len = msgs[dev->msg_write_idx].len;
/* If both IC_EMPTYFIFO_HOLD_MASTER_EN and
* IC_RESTART_EN are set, we must manually
* set restart bit between messages.
*/
if ((dev->master_cfg & DW_IC_CON_RESTART_EN) &&
(dev->msg_write_idx > 0))
need_restart = true;
}
tx_limit = dev->tx_fifo_depth - dw_readl(dev, DW_IC_TXFLR);
rx_limit = dev->rx_fifo_depth - dw_readl(dev, DW_IC_RXFLR);
while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) {
u32 cmd = 0;
/*
* If IC_EMPTYFIFO_HOLD_MASTER_EN is set we must
* manually set the stop bit. However, it cannot be
* detected from the registers so we set it always
* when writing/reading the last byte.
*/
/*
* i2c-core always sets the buffer length of
* I2C_FUNC_SMBUS_BLOCK_DATA to 1. The length will
* be adjusted when receiving the first byte.
* Thus we can't stop the transaction here.
*/
if (dev->msg_write_idx == dev->msgs_num - 1 &&
buf_len == 1 && !(flags & I2C_M_RECV_LEN))
cmd |= BIT(9);
if (need_restart) {
cmd |= BIT(10);
need_restart = false;
}
if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
/* Avoid rx buffer overrun */
2016-11-19 03:40:10 +08:00
if (dev->rx_outstanding >= dev->rx_fifo_depth)
break;
dw_writel(dev, cmd | 0x100, DW_IC_DATA_CMD);
rx_limit--;
dev->rx_outstanding++;
} else
dw_writel(dev, cmd | *buf++, DW_IC_DATA_CMD);
tx_limit--; buf_len--;
}
dev->tx_buf = buf;
dev->tx_buf_len = buf_len;
/*
* Because we don't know the buffer length in the
* I2C_FUNC_SMBUS_BLOCK_DATA case, we can't stop
* the transaction here.
*/
if (buf_len > 0 || flags & I2C_M_RECV_LEN) {
/* more bytes to be written */
dev->status |= STATUS_WRITE_IN_PROGRESS;
break;
} else
dev->status &= ~STATUS_WRITE_IN_PROGRESS;
}
/*
* If i2c_msg index search is completed, we don't need TX_EMPTY
* interrupt any more.
*/
if (dev->msg_write_idx == dev->msgs_num)
intr_mask &= ~DW_IC_INTR_TX_EMPTY;
if (dev->msg_err)
intr_mask = 0;
dw_writel(dev, intr_mask, DW_IC_INTR_MASK);
}
static u8
i2c_dw_recv_len(struct dw_i2c_dev *dev, u8 len)
{
struct i2c_msg *msgs = dev->msgs;
u32 flags = msgs[dev->msg_read_idx].flags;
/*
* Adjust the buffer length and mask the flag
* after receiving the first byte.
*/
len += (flags & I2C_CLIENT_PEC) ? 2 : 1;
dev->tx_buf_len = len - min_t(u8, len, dev->rx_outstanding);
msgs[dev->msg_read_idx].len = len;
msgs[dev->msg_read_idx].flags &= ~I2C_M_RECV_LEN;
return len;
}
static void
i2c_dw_read(struct dw_i2c_dev *dev)
{
struct i2c_msg *msgs = dev->msgs;
int rx_valid;
for (; dev->msg_read_idx < dev->msgs_num; dev->msg_read_idx++) {
u32 len;
u8 *buf;
if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD))
continue;
if (!(dev->status & STATUS_READ_IN_PROGRESS)) {
len = msgs[dev->msg_read_idx].len;
buf = msgs[dev->msg_read_idx].buf;
} else {
len = dev->rx_buf_len;
buf = dev->rx_buf;
}
rx_valid = dw_readl(dev, DW_IC_RXFLR);
for (; len > 0 && rx_valid > 0; len--, rx_valid--) {
u32 flags = msgs[dev->msg_read_idx].flags;
*buf = dw_readl(dev, DW_IC_DATA_CMD);
/* Ensure length byte is a valid value */
if (flags & I2C_M_RECV_LEN &&
*buf <= I2C_SMBUS_BLOCK_MAX && *buf > 0) {
len = i2c_dw_recv_len(dev, *buf);
}
buf++;
dev->rx_outstanding--;
}
if (len > 0) {
dev->status |= STATUS_READ_IN_PROGRESS;
dev->rx_buf_len = len;
dev->rx_buf = buf;
return;
} else
dev->status &= ~STATUS_READ_IN_PROGRESS;
}
}
/*
* Prepare controller for a transaction and call i2c_dw_xfer_msg.
*/
static int
i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
{
struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
int ret;
dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
pm_runtime_get_sync(dev->dev);
reinit_completion(&dev->cmd_complete);
dev->msgs = msgs;
dev->msgs_num = num;
dev->cmd_err = 0;
dev->msg_write_idx = 0;
dev->msg_read_idx = 0;
dev->msg_err = 0;
dev->status = STATUS_IDLE;
dev->abort_source = 0;
dev->rx_outstanding = 0;
ret = i2c_dw_acquire_lock(dev);
if (ret)
goto done_nolock;
ret = i2c_dw_wait_bus_not_busy(dev);
if (ret < 0)
goto done;
/* Start the transfers */
i2c_dw_xfer_init(dev);
/* Wait for tx to complete */
if (!wait_for_completion_timeout(&dev->cmd_complete, adap->timeout)) {
dev_err(dev->dev, "controller timed out\n");
/* i2c_dw_init implicitly disables the adapter */
i2c_recover_bus(&dev->adapter);
i2c_dw_init_master(dev);
ret = -ETIMEDOUT;
goto done;
}
/*
* We must disable the adapter before returning and signaling the end
* of the current transfer. Otherwise the hardware might continue
* generating interrupts which in turn causes a race condition with
* the following transfer. Needs some more investigation if the
* additional interrupts are a hardware bug or this driver doesn't
* handle them correctly yet.
*/
__i2c_dw_enable(dev, false);
if (dev->msg_err) {
ret = dev->msg_err;
goto done;
}
/* No error */
if (likely(!dev->cmd_err && !dev->status)) {
ret = num;
goto done;
}
/* We have an error */
if (dev->cmd_err == DW_IC_ERR_TX_ABRT) {
ret = i2c_dw_handle_tx_abort(dev);
goto done;
}
if (dev->status)
dev_err(dev->dev,
"transfer terminated early - interrupt latency too high?\n");
ret = -EIO;
done:
i2c_dw_release_lock(dev);
done_nolock:
pm_runtime_mark_last_busy(dev->dev);
pm_runtime_put_autosuspend(dev->dev);
return ret;
}
static const struct i2c_algorithm i2c_dw_algo = {
.master_xfer = i2c_dw_xfer,
.functionality = i2c_dw_func,
};
static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev)
{
u32 stat;
/*
* The IC_INTR_STAT register just indicates "enabled" interrupts.
* Ths unmasked raw version of interrupt status bits are available
* in the IC_RAW_INTR_STAT register.
*
* That is,
* stat = dw_readl(IC_INTR_STAT);
* equals to,
* stat = dw_readl(IC_RAW_INTR_STAT) & dw_readl(IC_INTR_MASK);
*
* The raw version might be useful for debugging purposes.
*/
stat = dw_readl(dev, DW_IC_INTR_STAT);
/*
* Do not use the IC_CLR_INTR register to clear interrupts, or
* you'll miss some interrupts, triggered during the period from
* dw_readl(IC_INTR_STAT) to dw_readl(IC_CLR_INTR).
*
* Instead, use the separately-prepared IC_CLR_* registers.
*/
if (stat & DW_IC_INTR_RX_UNDER)
dw_readl(dev, DW_IC_CLR_RX_UNDER);
if (stat & DW_IC_INTR_RX_OVER)
dw_readl(dev, DW_IC_CLR_RX_OVER);
if (stat & DW_IC_INTR_TX_OVER)
dw_readl(dev, DW_IC_CLR_TX_OVER);
if (stat & DW_IC_INTR_RD_REQ)
dw_readl(dev, DW_IC_CLR_RD_REQ);
if (stat & DW_IC_INTR_TX_ABRT) {
/*
* The IC_TX_ABRT_SOURCE register is cleared whenever
* the IC_CLR_TX_ABRT is read. Preserve it beforehand.
*/
dev->abort_source = dw_readl(dev, DW_IC_TX_ABRT_SOURCE);
dw_readl(dev, DW_IC_CLR_TX_ABRT);
}
if (stat & DW_IC_INTR_RX_DONE)
dw_readl(dev, DW_IC_CLR_RX_DONE);
if (stat & DW_IC_INTR_ACTIVITY)
dw_readl(dev, DW_IC_CLR_ACTIVITY);
if (stat & DW_IC_INTR_STOP_DET)
dw_readl(dev, DW_IC_CLR_STOP_DET);
if (stat & DW_IC_INTR_START_DET)
dw_readl(dev, DW_IC_CLR_START_DET);
if (stat & DW_IC_INTR_GEN_CALL)
dw_readl(dev, DW_IC_CLR_GEN_CALL);
return stat;
}
/*
* Interrupt service routine. This gets called whenever an I2C master interrupt
* occurs.
*/
static int i2c_dw_irq_handler_master(struct dw_i2c_dev *dev)
{
u32 stat;
stat = i2c_dw_read_clear_intrbits(dev);
if (stat & DW_IC_INTR_TX_ABRT) {
dev->cmd_err |= DW_IC_ERR_TX_ABRT;
dev->status = STATUS_IDLE;
/*
* Anytime TX_ABRT is set, the contents of the tx/rx
* buffers are flushed. Make sure to skip them.
*/
dw_writel(dev, 0, DW_IC_INTR_MASK);
goto tx_aborted;
}
if (stat & DW_IC_INTR_RX_FULL)
i2c_dw_read(dev);
if (stat & DW_IC_INTR_TX_EMPTY)
i2c_dw_xfer_msg(dev);
/*
* No need to modify or disable the interrupt mask here.
* i2c_dw_xfer_msg() will take care of it according to
* the current transmit status.
*/
tx_aborted:
if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err)
complete(&dev->cmd_complete);
else if (unlikely(dev->flags & ACCESS_INTR_MASK)) {
/* Workaround to trigger pending interrupt */
stat = dw_readl(dev, DW_IC_INTR_MASK);
i2c_dw_disable_int(dev);
dw_writel(dev, stat, DW_IC_INTR_MASK);
}
return 0;
}
static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
{
struct dw_i2c_dev *dev = dev_id;
u32 stat, enabled;
enabled = dw_readl(dev, DW_IC_ENABLE);
stat = dw_readl(dev, DW_IC_RAW_INTR_STAT);
dev_dbg(dev->dev, "enabled=%#x stat=%#x\n", enabled, stat);
if (!enabled || !(stat & ~DW_IC_INTR_ACTIVITY))
return IRQ_NONE;
i2c_dw_irq_handler_master(dev);
return IRQ_HANDLED;
}
static void i2c_dw_prepare_recovery(struct i2c_adapter *adap)
{
struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
i2c_dw_disable(dev);
reset_control_assert(dev->rst);
i2c_dw_prepare_clk(dev, false);
}
static void i2c_dw_unprepare_recovery(struct i2c_adapter *adap)
{
struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
i2c_dw_prepare_clk(dev, true);
reset_control_deassert(dev->rst);
i2c_dw_init_master(dev);
}
static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev)
{
struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
struct i2c_adapter *adap = &dev->adapter;
struct gpio_desc *gpio;
int r;
gpio = devm_gpiod_get(dev->dev, "scl", GPIOD_OUT_HIGH);
if (IS_ERR(gpio)) {
r = PTR_ERR(gpio);
if (r == -ENOENT || r == -ENOSYS)
return 0;
return r;
}
rinfo->scl_gpiod = gpio;
gpio = devm_gpiod_get_optional(dev->dev, "sda", GPIOD_IN);
if (IS_ERR(gpio))
return PTR_ERR(gpio);
rinfo->sda_gpiod = gpio;
rinfo->recover_bus = i2c_generic_scl_recovery;
rinfo->prepare_recovery = i2c_dw_prepare_recovery;
rinfo->unprepare_recovery = i2c_dw_unprepare_recovery;
adap->bus_recovery_info = rinfo;
dev_info(dev->dev, "running with gpio recovery mode! scl%s",
rinfo->sda_gpiod ? ",sda" : "");
return 0;
}
int i2c_dw_probe(struct dw_i2c_dev *dev)
{
struct i2c_adapter *adap = &dev->adapter;
i2c: designware: Never suspend i2c-busses used for accessing the system PMIC Currently we are already setting a pm_runtime_disabled flag and disabling runtime-pm for i2c-busses used for accessing the system PMIC on x86. But this is not enough, there are ACPI opregions which may want to access the PMIC during late-suspend and early-resume, so we need to completely disable pm to be safe. This commit renames the flag from pm_runtime_disabled to pm_disabled and adds the following new behavior if the flag is set: 1) Call dev_pm_syscore_device(dev, true) which disables normal suspend / resume and remove the pm_runtime_disabled check from dw_i2c_plat_resume since that will now never get called. This fixes suspend_late handlers which use ACPI PMIC opregions causing errors like these: PM: Suspending system (freeze) PM: suspend of devices complete after 1127.751 msecs i2c_designware 808622C1:06: timeout waiting for bus ready ACPI Exception: AE_ERROR, Returned by Handler for [UserDefinedRegion] acpi 80860F14:02: Failed to change power state to D3hot PM: late suspend of devices failed 2) Set IRQF_NO_SUSPEND irq flag. This fixes resume_early handlers which handlers which use ACPI PMIC opregions causing errors like these: PM: resume from suspend-to-idle i2c_designware 808622C1:06: controller timed out ACPI Exception: AE_ERROR, Returned by Handler for [UserDefinedRegion] Signed-off-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-03-14 06:25:09 +08:00
unsigned long irq_flags;
int ret;
init_completion(&dev->cmd_complete);
dev->init = i2c_dw_init_master;
dev->disable = i2c_dw_disable;
dev->disable_int = i2c_dw_disable_int;
ret = dev->init(dev);
if (ret)
return ret;
snprintf(adap->name, sizeof(adap->name),
"Synopsys DesignWare I2C adapter");
adap->retries = 3;
adap->algo = &i2c_dw_algo;
adap->dev.parent = dev->dev;
i2c_set_adapdata(adap, dev);
i2c: designware: Never suspend i2c-busses used for accessing the system PMIC Currently we are already setting a pm_runtime_disabled flag and disabling runtime-pm for i2c-busses used for accessing the system PMIC on x86. But this is not enough, there are ACPI opregions which may want to access the PMIC during late-suspend and early-resume, so we need to completely disable pm to be safe. This commit renames the flag from pm_runtime_disabled to pm_disabled and adds the following new behavior if the flag is set: 1) Call dev_pm_syscore_device(dev, true) which disables normal suspend / resume and remove the pm_runtime_disabled check from dw_i2c_plat_resume since that will now never get called. This fixes suspend_late handlers which use ACPI PMIC opregions causing errors like these: PM: Suspending system (freeze) PM: suspend of devices complete after 1127.751 msecs i2c_designware 808622C1:06: timeout waiting for bus ready ACPI Exception: AE_ERROR, Returned by Handler for [UserDefinedRegion] acpi 80860F14:02: Failed to change power state to D3hot PM: late suspend of devices failed 2) Set IRQF_NO_SUSPEND irq flag. This fixes resume_early handlers which handlers which use ACPI PMIC opregions causing errors like these: PM: resume from suspend-to-idle i2c_designware 808622C1:06: controller timed out ACPI Exception: AE_ERROR, Returned by Handler for [UserDefinedRegion] Signed-off-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-03-14 06:25:09 +08:00
if (dev->pm_disabled) {
dev_pm_syscore_device(dev->dev, true);
irq_flags = IRQF_NO_SUSPEND;
} else {
irq_flags = IRQF_SHARED | IRQF_COND_SUSPEND;
}
i2c_dw_disable_int(dev);
ret = devm_request_irq(dev->dev, dev->irq, i2c_dw_isr, irq_flags,
dev_name(dev->dev), dev);
if (ret) {
dev_err(dev->dev, "failure requesting irq %i: %d\n",
dev->irq, ret);
return ret;
}
ret = i2c_dw_init_recovery_info(dev);
if (ret)
return ret;
/*
* Increment PM usage count during adapter registration in order to
* avoid possible spurious runtime suspend when adapter device is
* registered to the device core and immediate resume in case bus has
* registered I2C slaves that do I2C transfers in their probe.
*/
pm_runtime_get_noresume(dev->dev);
ret = i2c_add_numbered_adapter(adap);
if (ret)
dev_err(dev->dev, "failure adding adapter: %d\n", ret);
pm_runtime_put_noidle(dev->dev);
return ret;
}
EXPORT_SYMBOL_GPL(i2c_dw_probe);
MODULE_DESCRIPTION("Synopsys DesignWare I2C bus master adapter");
MODULE_LICENSE("GPL");