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

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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.
*/
#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/regmap.h>
#include <linux/reset.h>
#include "i2c-designware-core.h"
#define AMD_TIMEOUT_MIN_US 25
#define AMD_TIMEOUT_MAX_US 250
#define AMD_MASTERCFG_MASK GENMASK(15, 0)
static void i2c_dw_configure_fifo_master(struct dw_i2c_dev *dev)
{
/* Configure Tx/Rx FIFO threshold levels */
regmap_write(dev->map, DW_IC_TX_TL, dev->tx_fifo_depth / 2);
regmap_write(dev->map, DW_IC_RX_TL, 0);
/* Configure the I2C master */
regmap_write(dev->map, DW_IC_CON, dev->master_cfg);
}
static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev)
{
unsigned int comp_param1;
u32 sda_falling_time, scl_falling_time;
struct i2c_timings *t = &dev->timings;
const char *fp_str = "";
u32 ic_clk;
int ret;
ret = i2c_dw_acquire_lock(dev);
if (ret)
return ret;
ret = regmap_read(dev->map, DW_IC_COMP_PARAM_1, &comp_param1);
i2c_dw_release_lock(dev);
if (ret)
return ret;
/* Set standard and fast speed dividers for high/low periods */
sda_falling_time = t->sda_fall_ns ?: 300; /* ns */
scl_falling_time = t->scl_fall_ns ?: 300; /* ns */
/* Calculate SCL timing parameters for standard mode if not set */
if (!dev->ss_hcnt || !dev->ss_lcnt) {
ic_clk = i2c_dw_clk_rate(dev);
dev->ss_hcnt =
i2c_dw_scl_hcnt(ic_clk,
4000, /* tHD;STA = tHIGH = 4.0 us */
sda_falling_time,
0, /* 0: DW default, 1: Ideal */
0); /* No offset */
dev->ss_lcnt =
i2c_dw_scl_lcnt(ic_clk,
4700, /* tLOW = 4.7 us */
scl_falling_time,
0); /* No offset */
}
dev_dbg(dev->dev, "Standard Mode HCNT:LCNT = %d:%d\n",
dev->ss_hcnt, dev->ss_lcnt);
/*
* Set SCL timing parameters for fast mode or fast mode plus. Only
* difference is the timing parameter values since the registers are
* the same.
*/
if (t->bus_freq_hz == I2C_MAX_FAST_MODE_PLUS_FREQ) {
/*
* Check are Fast Mode Plus parameters available. Calculate
* SCL timing parameters for Fast Mode Plus if not set.
*/
if (dev->fp_hcnt && dev->fp_lcnt) {
dev->fs_hcnt = dev->fp_hcnt;
dev->fs_lcnt = dev->fp_lcnt;
} else {
ic_clk = i2c_dw_clk_rate(dev);
dev->fs_hcnt =
i2c_dw_scl_hcnt(ic_clk,
260, /* tHIGH = 260 ns */
sda_falling_time,
0, /* DW default */
0); /* No offset */
dev->fs_lcnt =
i2c_dw_scl_lcnt(ic_clk,
500, /* tLOW = 500 ns */
scl_falling_time,
0); /* No offset */
}
fp_str = " Plus";
}
/*
* Calculate SCL timing parameters for fast mode if not set. They are
* needed also in high speed mode.
*/
if (!dev->fs_hcnt || !dev->fs_lcnt) {
ic_clk = i2c_dw_clk_rate(dev);
dev->fs_hcnt =
i2c_dw_scl_hcnt(ic_clk,
600, /* tHD;STA = tHIGH = 0.6 us */
sda_falling_time,
0, /* 0: DW default, 1: Ideal */
0); /* No offset */
dev->fs_lcnt =
i2c_dw_scl_lcnt(ic_clk,
1300, /* tLOW = 1.3 us */
scl_falling_time,
0); /* No offset */
}
dev_dbg(dev->dev, "Fast Mode%s HCNT:LCNT = %d:%d\n",
fp_str, dev->fs_hcnt, dev->fs_lcnt);
/* Check is high speed possible and fall back to fast mode if not */
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");
t->bus_freq_hz = I2C_MAX_FAST_MODE_FREQ;
dev->master_cfg &= ~DW_IC_CON_SPEED_MASK;
dev->master_cfg |= DW_IC_CON_SPEED_FAST;
dev->hs_hcnt = 0;
dev->hs_lcnt = 0;
} else if (!dev->hs_hcnt || !dev->hs_lcnt) {
ic_clk = i2c_dw_clk_rate(dev);
dev->hs_hcnt =
i2c_dw_scl_hcnt(ic_clk,
160, /* tHIGH = 160 ns */
sda_falling_time,
0, /* DW default */
0); /* No offset */
dev->hs_lcnt =
i2c_dw_scl_lcnt(ic_clk,
320, /* tLOW = 320 ns */
scl_falling_time,
0); /* No offset */
}
dev_dbg(dev->dev, "High Speed Mode HCNT:LCNT = %d:%d\n",
dev->hs_hcnt, dev->hs_lcnt);
}
ret = i2c_dw_set_sda_hold(dev);
if (ret)
return ret;
dev_dbg(dev->dev, "Bus speed: %s\n", i2c_freq_mode_string(t->bus_freq_hz));
return 0;
}
/**
* i2c_dw_init_master() - 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)
{
int ret;
ret = i2c_dw_acquire_lock(dev);
if (ret)
return ret;
/* Disable the adapter */
__i2c_dw_disable(dev);
/* Write standard speed timing parameters */
regmap_write(dev->map, DW_IC_SS_SCL_HCNT, dev->ss_hcnt);
regmap_write(dev->map, DW_IC_SS_SCL_LCNT, dev->ss_lcnt);
/* Write fast mode/fast mode plus timing parameters */
regmap_write(dev->map, DW_IC_FS_SCL_HCNT, dev->fs_hcnt);
regmap_write(dev->map, DW_IC_FS_SCL_LCNT, dev->fs_lcnt);
/* Write high speed timing parameters if supported */
if (dev->hs_hcnt && dev->hs_lcnt) {
regmap_write(dev->map, DW_IC_HS_SCL_HCNT, dev->hs_hcnt);
regmap_write(dev->map, DW_IC_HS_SCL_LCNT, dev->hs_lcnt);
}
/* Write SDA hold time if supported */
if (dev->sda_hold_time)
regmap_write(dev->map, DW_IC_SDA_HOLD, dev->sda_hold_time);
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 = 0, ic_tar = 0;
unsigned int dummy;
/* Disable the adapter */
__i2c_dw_disable(dev);
/* If the slave address is ten bit address, enable 10BITADDR */
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;
}
regmap_update_bits(dev->map, DW_IC_CON, DW_IC_CON_10BITADDR_MASTER,
ic_con);
/*
* Set the slave (target) address and enable 10-bit addressing mode
* if applicable.
*/
regmap_write(dev->map, DW_IC_TAR,
msgs[dev->msg_write_idx].addr | ic_tar);
/* Enforce disabled interrupts (due to HW issues) */
regmap_write(dev->map, DW_IC_INTR_MASK, 0);
/* Enable the adapter */
__i2c_dw_enable(dev);
/* Dummy read to avoid the register getting stuck on Bay Trail */
regmap_read(dev->map, DW_IC_ENABLE_STATUS, &dummy);
/* Clear and enable interrupts */
regmap_read(dev->map, DW_IC_CLR_INTR, &dummy);
regmap_write(dev->map, DW_IC_INTR_MASK, DW_IC_INTR_MASTER_MASK);
}
static int i2c_dw_check_stopbit(struct dw_i2c_dev *dev)
{
u32 val;
int ret;
ret = regmap_read_poll_timeout(dev->map, DW_IC_INTR_STAT, val,
!(val & DW_IC_INTR_STOP_DET),
1100, 20000);
if (ret)
dev_err(dev->dev, "i2c timeout error %d\n", ret);
return ret;
}
static int i2c_dw_status(struct dw_i2c_dev *dev)
{
int status;
status = i2c_dw_wait_bus_not_busy(dev);
if (status)
return status;
return i2c_dw_check_stopbit(dev);
}
/*
* Initiate and continue master read/write transaction with polling
* based transfer routine afterward write messages into the Tx buffer.
*/
static int amd_i2c_dw_xfer_quirk(struct i2c_adapter *adap, struct i2c_msg *msgs, int num_msgs)
{
struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
int msg_wrt_idx, msg_itr_lmt, buf_len, data_idx;
int cmd = 0, status;
u8 *tx_buf;
unsigned int val;
/*
* In order to enable the interrupt for UCSI i.e. AMD NAVI GPU card,
* it is mandatory to set the right value in specific register
* (offset:0x474) as per the hardware IP specification.
*/
regmap_write(dev->map, AMD_UCSI_INTR_REG, AMD_UCSI_INTR_EN);
dev->msgs = msgs;
dev->msgs_num = num_msgs;
i2c_dw_xfer_init(dev);
regmap_write(dev->map, DW_IC_INTR_MASK, 0);
/* Initiate messages read/write transaction */
for (msg_wrt_idx = 0; msg_wrt_idx < num_msgs; msg_wrt_idx++) {
tx_buf = msgs[msg_wrt_idx].buf;
buf_len = msgs[msg_wrt_idx].len;
if (!(msgs[msg_wrt_idx].flags & I2C_M_RD))
regmap_write(dev->map, DW_IC_TX_TL, buf_len - 1);
/*
* Initiate the i2c read/write transaction of buffer length,
* and poll for bus busy status. For the last message transfer,
* update the command with stopbit enable.
*/
for (msg_itr_lmt = buf_len; msg_itr_lmt > 0; msg_itr_lmt--) {
if (msg_wrt_idx == num_msgs - 1 && msg_itr_lmt == 1)
cmd |= BIT(9);
if (msgs[msg_wrt_idx].flags & I2C_M_RD) {
/* Due to hardware bug, need to write the same command twice. */
regmap_write(dev->map, DW_IC_DATA_CMD, 0x100);
regmap_write(dev->map, DW_IC_DATA_CMD, 0x100 | cmd);
if (cmd) {
regmap_write(dev->map, DW_IC_TX_TL, 2 * (buf_len - 1));
regmap_write(dev->map, DW_IC_RX_TL, 2 * (buf_len - 1));
/*
* Need to check the stop bit. However, it cannot be
* detected from the registers so we check it always
* when read/write the last byte.
*/
status = i2c_dw_status(dev);
if (status)
return status;
for (data_idx = 0; data_idx < buf_len; data_idx++) {
regmap_read(dev->map, DW_IC_DATA_CMD, &val);
tx_buf[data_idx] = val;
}
status = i2c_dw_check_stopbit(dev);
if (status)
return status;
}
} else {
regmap_write(dev->map, DW_IC_DATA_CMD, *tx_buf++ | cmd);
usleep_range(AMD_TIMEOUT_MIN_US, AMD_TIMEOUT_MAX_US);
}
}
status = i2c_dw_check_stopbit(dev);
if (status)
return status;
}
return 0;
}
static int i2c_dw_poll_tx_empty(struct dw_i2c_dev *dev)
{
u32 val;
return regmap_read_poll_timeout(dev->map, DW_IC_RAW_INTR_STAT, val,
val & DW_IC_INTR_TX_EMPTY,
100, 1000);
}
static int i2c_dw_poll_rx_full(struct dw_i2c_dev *dev)
{
u32 val;
return regmap_read_poll_timeout(dev->map, DW_IC_RAW_INTR_STAT, val,
val & DW_IC_INTR_RX_FULL,
100, 1000);
}
static int txgbe_i2c_dw_xfer_quirk(struct i2c_adapter *adap, struct i2c_msg *msgs,
int num_msgs)
{
struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
int msg_idx, buf_len, data_idx, ret;
unsigned int val, stop = 0;
u8 *buf;
dev->msgs = msgs;
dev->msgs_num = num_msgs;
i2c_dw_xfer_init(dev);
regmap_write(dev->map, DW_IC_INTR_MASK, 0);
for (msg_idx = 0; msg_idx < num_msgs; msg_idx++) {
buf = msgs[msg_idx].buf;
buf_len = msgs[msg_idx].len;
for (data_idx = 0; data_idx < buf_len; data_idx++) {
if (msg_idx == num_msgs - 1 && data_idx == buf_len - 1)
stop |= BIT(9);
if (msgs[msg_idx].flags & I2C_M_RD) {
regmap_write(dev->map, DW_IC_DATA_CMD, 0x100 | stop);
ret = i2c_dw_poll_rx_full(dev);
if (ret)
return ret;
regmap_read(dev->map, DW_IC_DATA_CMD, &val);
buf[data_idx] = val;
} else {
ret = i2c_dw_poll_tx_empty(dev);
if (ret)
return ret;
regmap_write(dev->map, DW_IC_DATA_CMD,
buf[data_idx] | stop);
}
}
}
return num_msgs;
}
/*
* 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;
unsigned int flr;
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 (!(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;
}
regmap_read(dev->map, DW_IC_TXFLR, &flr);
tx_limit = dev->tx_fifo_depth - flr;
regmap_read(dev->map, DW_IC_RXFLR, &flr);
rx_limit = dev->rx_fifo_depth - flr;
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 */
if (dev->rx_outstanding >= dev->rx_fifo_depth)
break;
regmap_write(dev->map, DW_IC_DATA_CMD,
cmd | 0x100);
rx_limit--;
dev->rx_outstanding++;
} else {
regmap_write(dev->map, DW_IC_DATA_CMD,
cmd | *buf++);
}
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;
regmap_write(dev->map, DW_IC_INTR_MASK, 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;
unsigned int rx_valid;
for (; dev->msg_read_idx < dev->msgs_num; dev->msg_read_idx++) {
unsigned int tmp;
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;
}
regmap_read(dev->map, DW_IC_RXFLR, &rx_valid);
for (; len > 0 && rx_valid > 0; len--, rx_valid--) {
u32 flags = msgs[dev->msg_read_idx].flags;
regmap_read(dev->map, DW_IC_DATA_CMD, &tmp);
tmp &= DW_IC_DATA_CMD_DAT;
/* Ensure length byte is a valid value */
if (flags & I2C_M_RECV_LEN) {
/*
* if IC_EMPTYFIFO_HOLD_MASTER_EN is set, which cannot be
* detected from the registers, the controller can be
* disabled if the STOP bit is set. But it is only set
* after receiving block data response length in
* I2C_FUNC_SMBUS_BLOCK_DATA case. That needs to read
* another byte with STOP bit set when the block data
* response length is invalid to complete the transaction.
*/
if (!tmp || tmp > I2C_SMBUS_BLOCK_MAX)
tmp = 1;
len = i2c_dw_recv_len(dev, tmp);
}
*buf++ = tmp;
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);
/*
* Initiate I2C message transfer when polling mode is enabled,
* As it is polling based transfer mechanism, which does not support
* interrupt based functionalities of existing DesignWare driver.
*/
switch (dev->flags & MODEL_MASK) {
case MODEL_AMD_NAVI_GPU:
ret = amd_i2c_dw_xfer_quirk(adap, msgs, num);
goto done_nolock;
case MODEL_WANGXUN_SP:
ret = txgbe_i2c_dw_xfer_quirk(adap, msgs, num);
goto done_nolock;
default:
break;
}
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 = 0;
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_disable_nowait(dev);
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 const struct i2c_adapter_quirks i2c_dw_quirks = {
.flags = I2C_AQ_NO_ZERO_LEN,
};
static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev)
{
unsigned int stat, dummy;
/*
* The IC_INTR_STAT register just indicates "enabled" interrupts.
* The unmasked raw version of interrupt status bits is available
* in the IC_RAW_INTR_STAT register.
*
* That is,
* stat = readl(IC_INTR_STAT);
* equals to,
* stat = readl(IC_RAW_INTR_STAT) & readl(IC_INTR_MASK);
*
* The raw version might be useful for debugging purposes.
*/
regmap_read(dev->map, DW_IC_INTR_STAT, &stat);
/*
* Do not use the IC_CLR_INTR register to clear interrupts, or
* you'll miss some interrupts, triggered during the period from
* readl(IC_INTR_STAT) to readl(IC_CLR_INTR).
*
* Instead, use the separately-prepared IC_CLR_* registers.
*/
if (stat & DW_IC_INTR_RX_UNDER)
regmap_read(dev->map, DW_IC_CLR_RX_UNDER, &dummy);
if (stat & DW_IC_INTR_RX_OVER)
regmap_read(dev->map, DW_IC_CLR_RX_OVER, &dummy);
if (stat & DW_IC_INTR_TX_OVER)
regmap_read(dev->map, DW_IC_CLR_TX_OVER, &dummy);
if (stat & DW_IC_INTR_RD_REQ)
regmap_read(dev->map, DW_IC_CLR_RD_REQ, &dummy);
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.
*/
regmap_read(dev->map, DW_IC_TX_ABRT_SOURCE, &dev->abort_source);
regmap_read(dev->map, DW_IC_CLR_TX_ABRT, &dummy);
}
if (stat & DW_IC_INTR_RX_DONE)
regmap_read(dev->map, DW_IC_CLR_RX_DONE, &dummy);
if (stat & DW_IC_INTR_ACTIVITY)
regmap_read(dev->map, DW_IC_CLR_ACTIVITY, &dummy);
if ((stat & DW_IC_INTR_STOP_DET) &&
((dev->rx_outstanding == 0) || (stat & DW_IC_INTR_RX_FULL)))
regmap_read(dev->map, DW_IC_CLR_STOP_DET, &dummy);
if (stat & DW_IC_INTR_START_DET)
regmap_read(dev->map, DW_IC_CLR_START_DET, &dummy);
if (stat & DW_IC_INTR_GEN_CALL)
regmap_read(dev->map, DW_IC_CLR_GEN_CALL, &dummy);
return stat;
}
/*
* Interrupt service routine. This gets called whenever an I2C master interrupt
* occurs.
*/
static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
{
struct dw_i2c_dev *dev = dev_id;
unsigned int stat, enabled;
regmap_read(dev->map, DW_IC_ENABLE, &enabled);
regmap_read(dev->map, DW_IC_RAW_INTR_STAT, &stat);
if (!enabled || !(stat & ~DW_IC_INTR_ACTIVITY))
return IRQ_NONE;
if (pm_runtime_suspended(dev->dev) || stat == GENMASK(31, 0))
return IRQ_NONE;
dev_dbg(dev->dev, "enabled=%#x stat=%#x\n", enabled, stat);
stat = i2c_dw_read_clear_intrbits(dev);
if (!(dev->status & STATUS_ACTIVE)) {
/*
* Unexpected interrupt in driver point of view. State
* variables are either unset or stale so acknowledge and
* disable interrupts for suppressing further interrupts if
* interrupt really came from this HW (E.g. firmware has left
* the HW active).
*/
regmap_write(dev->map, DW_IC_INTR_MASK, 0);
return IRQ_HANDLED;
}
if (stat & DW_IC_INTR_TX_ABRT) {
dev->cmd_err |= DW_IC_ERR_TX_ABRT;
dev->status &= ~STATUS_MASK;
dev->rx_outstanding = 0;
/*
* Anytime TX_ABRT is set, the contents of the tx/rx
* buffers are flushed. Make sure to skip them.
*/
regmap_write(dev->map, DW_IC_INTR_MASK, 0);
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) &&
(dev->rx_outstanding == 0))
complete(&dev->cmd_complete);
else if (unlikely(dev->flags & ACCESS_INTR_MASK)) {
/* Workaround to trigger pending interrupt */
regmap_read(dev->map, DW_IC_INTR_MASK, &stat);
regmap_write(dev->map, DW_IC_INTR_MASK, 0);
regmap_write(dev->map, DW_IC_INTR_MASK, stat);
}
return IRQ_HANDLED;
}
void i2c_dw_configure_master(struct dw_i2c_dev *dev)
{
struct i2c_timings *t = &dev->timings;
dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY;
dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
DW_IC_CON_RESTART_EN;
dev->mode = DW_IC_MASTER;
switch (t->bus_freq_hz) {
case I2C_MAX_STANDARD_MODE_FREQ:
dev->master_cfg |= DW_IC_CON_SPEED_STD;
break;
case I2C_MAX_HIGH_SPEED_MODE_FREQ:
dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
break;
default:
dev->master_cfg |= DW_IC_CON_SPEED_FAST;
}
}
EXPORT_SYMBOL_GPL(i2c_dw_configure_master);
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;
gpio = devm_gpiod_get_optional(dev->dev, "scl", GPIOD_OUT_HIGH);
if (IS_ERR_OR_NULL(gpio))
return PTR_ERR_OR_ZERO(gpio);
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;
}
static int i2c_dw_poll_adap_quirk(struct dw_i2c_dev *dev)
{
struct i2c_adapter *adap = &dev->adapter;
int ret;
pm_runtime_get_noresume(dev->dev);
ret = i2c_add_numbered_adapter(adap);
if (ret)
dev_err(dev->dev, "Failed to add adapter: %d\n", ret);
pm_runtime_put_noidle(dev->dev);
return ret;
}
static bool i2c_dw_is_model_poll(struct dw_i2c_dev *dev)
{
switch (dev->flags & MODEL_MASK) {
case MODEL_AMD_NAVI_GPU:
case MODEL_WANGXUN_SP:
return true;
default:
return false;
}
}
int i2c_dw_probe_master(struct dw_i2c_dev *dev)
{
struct i2c_adapter *adap = &dev->adapter;
unsigned long irq_flags;
unsigned int ic_con;
int ret;
init_completion(&dev->cmd_complete);
dev->init = i2c_dw_init_master;
dev->disable = i2c_dw_disable;
ret = i2c_dw_init_regmap(dev);
if (ret)
return ret;
ret = i2c_dw_set_timings_master(dev);
if (ret)
return ret;
ret = i2c_dw_set_fifo_size(dev);
if (ret)
return ret;
/* Lock the bus for accessing DW_IC_CON */
ret = i2c_dw_acquire_lock(dev);
if (ret)
return ret;
/*
* On AMD platforms BIOS advertises the bus clear feature
* and enables the SCL/SDA stuck low. SMU FW does the
* bus recovery process. Driver should not ignore this BIOS
* advertisement of bus clear feature.
*/
ret = regmap_read(dev->map, DW_IC_CON, &ic_con);
i2c_dw_release_lock(dev);
if (ret)
return ret;
if (ic_con & DW_IC_CON_BUS_CLEAR_CTRL)
dev->master_cfg |= DW_IC_CON_BUS_CLEAR_CTRL;
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->quirks = &i2c_dw_quirks;
adap->dev.parent = dev->dev;
i2c_set_adapdata(adap, dev);
if (i2c_dw_is_model_poll(dev))
return i2c_dw_poll_adap_quirk(dev);
if (dev->flags & ACCESS_NO_IRQ_SUSPEND) {
irq_flags = IRQF_NO_SUSPEND;
} else {
irq_flags = IRQF_SHARED | IRQF_COND_SUSPEND;
}
ret = i2c_dw_acquire_lock(dev);
if (ret)
return ret;
regmap_write(dev->map, DW_IC_INTR_MASK, 0);
i2c_dw_release_lock(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_master);
MODULE_DESCRIPTION("Synopsys DesignWare I2C bus master adapter");
MODULE_LICENSE("GPL");
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