/*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
* ----------------------------------------------------------------------------
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/clk.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/io.h>
/*
* Registers offset
*/
#define DW_IC_CON 0x0
#define DW_IC_TAR 0x4
#define DW_IC_DATA_CMD 0x10
#define DW_IC_SS_SCL_HCNT 0x14
#define DW_IC_SS_SCL_LCNT 0x18
#define DW_IC_FS_SCL_HCNT 0x1c
#define DW_IC_FS_SCL_LCNT 0x20
#define DW_IC_INTR_STAT 0x2c
#define DW_IC_INTR_MASK 0x30
#define DW_IC_RAW_INTR_STAT 0x34
#define DW_IC_RX_TL 0x38
#define DW_IC_TX_TL 0x3c
#define DW_IC_CLR_INTR 0x40
#define DW_IC_CLR_RX_UNDER 0x44
#define DW_IC_CLR_RX_OVER 0x48
#define DW_IC_CLR_TX_OVER 0x4c
#define DW_IC_CLR_RD_REQ 0x50
#define DW_IC_CLR_TX_ABRT 0x54
#define DW_IC_CLR_RX_DONE 0x58
#define DW_IC_CLR_ACTIVITY 0x5c
#define DW_IC_CLR_STOP_DET 0x60
#define DW_IC_CLR_START_DET 0x64
#define DW_IC_CLR_GEN_CALL 0x68
#define DW_IC_ENABLE 0x6c
#define DW_IC_STATUS 0x70
#define DW_IC_TXFLR 0x74
#define DW_IC_RXFLR 0x78
#define DW_IC_COMP_PARAM_1 0xf4
#define DW_IC_TX_ABRT_SOURCE 0x80
#define DW_IC_CON_MASTER 0x1
#define DW_IC_CON_SPEED_STD 0x2
#define DW_IC_CON_SPEED_FAST 0x4
#define DW_IC_CON_10BITADDR_MASTER 0x10
#define DW_IC_CON_RESTART_EN 0x20
#define DW_IC_CON_SLAVE_DISABLE 0x40
#define DW_IC_INTR_RX_UNDER 0x001
#define DW_IC_INTR_RX_OVER 0x002
#define DW_IC_INTR_RX_FULL 0x004
#define DW_IC_INTR_TX_OVER 0x008
#define DW_IC_INTR_TX_EMPTY 0x010
#define DW_IC_INTR_RD_REQ 0x020
#define DW_IC_INTR_TX_ABRT 0x040
#define DW_IC_INTR_RX_DONE 0x080
#define DW_IC_INTR_ACTIVITY 0x100
#define DW_IC_INTR_STOP_DET 0x200
#define DW_IC_INTR_START_DET 0x400
#define DW_IC_INTR_GEN_CALL 0x800
#define DW_IC_INTR_DEFAULT_MASK (DW_IC_INTR_RX_FULL | \
DW_IC_INTR_TX_EMPTY | \
DW_IC_INTR_TX_ABRT | \
DW_IC_INTR_STOP_DET)
#define DW_IC_STATUS_ACTIVITY 0x1
#define DW_IC_ERR_TX_ABRT 0x1
/*
* status codes
*/
#define STATUS_IDLE 0x0
#define STATUS_WRITE_IN_PROGRESS 0x1
#define STATUS_READ_IN_PROGRESS 0x2
#define TIMEOUT 20 /* ms */
/*
* hardware abort codes from the DW_IC_TX_ABRT_SOURCE register
*
* only expected abort codes are listed here
* refer to the datasheet for the full list
*/
#define ABRT_7B_ADDR_NOACK 0
#define ABRT_10ADDR1_NOACK 1
#define ABRT_10ADDR2_NOACK 2
#define ABRT_TXDATA_NOACK 3
#define ABRT_GCALL_NOACK 4
#define ABRT_GCALL_READ 5
#define ABRT_SBYTE_ACKDET 7
#define ABRT_SBYTE_NORSTRT 9
#define ABRT_10B_RD_NORSTRT 10
#define ABRT_MASTER_DIS 11
#define ARB_LOST 12
#define DW_IC_TX_ABRT_7B_ADDR_NOACK (1UL << ABRT_7B_ADDR_NOACK)
#define DW_IC_TX_ABRT_10ADDR1_NOACK (1UL << ABRT_10ADDR1_NOACK)
#define DW_IC_TX_ABRT_10ADDR2_NOACK (1UL << ABRT_10ADDR2_NOACK)
#define DW_IC_TX_ABRT_TXDATA_NOACK (1UL << ABRT_TXDATA_NOACK)
#define DW_IC_TX_ABRT_GCALL_NOACK (1UL << ABRT_GCALL_NOACK)
#define DW_IC_TX_ABRT_GCALL_READ (1UL << ABRT_GCALL_READ)
#define DW_IC_TX_ABRT_SBYTE_ACKDET (1UL << ABRT_SBYTE_ACKDET)
#define DW_IC_TX_ABRT_SBYTE_NORSTRT (1UL << ABRT_SBYTE_NORSTRT)
#define DW_IC_TX_ABRT_10B_RD_NORSTRT (1UL << ABRT_10B_RD_NORSTRT)
#define DW_IC_TX_ABRT_MASTER_DIS (1UL << ABRT_MASTER_DIS)
#define DW_IC_TX_ARB_LOST (1UL << ARB_LOST)
#define DW_IC_TX_ABRT_NOACK (DW_IC_TX_ABRT_7B_ADDR_NOACK | \
DW_IC_TX_ABRT_10ADDR1_NOACK | \
DW_IC_TX_ABRT_10ADDR2_NOACK | \
DW_IC_TX_ABRT_TXDATA_NOACK | \
DW_IC_TX_ABRT_GCALL_NOACK)
static char *abort_sources[] = {
[ABRT_7B_ADDR_NOACK] =
"slave address not acknowledged (7bit mode)",
[ABRT_10ADDR1_NOACK] =
"first address byte not acknowledged (10bit mode)",
[ABRT_10ADDR2_NOACK] =
"second address byte not acknowledged (10bit mode)",
[ABRT_TXDATA_NOACK] =
"data not acknowledged",
[ABRT_GCALL_NOACK] =
"no acknowledgement for a general call",
[ABRT_GCALL_READ] =
"read after general call",
[ABRT_SBYTE_ACKDET] =
"start byte acknowledged",
[ABRT_SBYTE_NORSTRT] =
"trying to send start byte when restart is disabled",
[ABRT_10B_RD_NORSTRT] =
"trying to read when restart is disabled (10bit mode)",
[ABRT_MASTER_DIS] =
"trying to use disabled adapter",
[ARB_LOST] =
"lost arbitration",
};
/**
* struct dw_i2c_dev - private i2c-designware data
* @dev: driver model device node
* @base: IO registers pointer
* @cmd_complete: tx completion indicator
* @lock: protect this struct and IO registers
* @clk: input reference clock
* @cmd_err: run time hadware error code
* @msgs: points to an array of messages currently being transfered
* @msgs_num: the number of elements in msgs
* @msg_write_idx: the element index of the current tx message in the msgs
* array
* @tx_buf_len: the length of the current tx buffer
* @tx_buf: the current tx buffer
* @msg_read_idx: the element index of the current rx message in the msgs
* array
* @rx_buf_len: the length of the current rx buffer
* @rx_buf: the current rx buffer
* @msg_err: error status of the current transfer
* @status: i2c master status, one of STATUS_*
* @abort_source: copy of the TX_ABRT_SOURCE register
* @irq: interrupt number for the i2c master
* @adapter: i2c subsystem adapter node
* @tx_fifo_depth: depth of the hardware tx fifo
* @rx_fifo_depth: depth of the hardware rx fifo
*/
struct dw_i2c_dev {
struct device *dev;
void __iomem *base;
struct completion cmd_complete;
struct mutex lock;
struct clk *clk;
int cmd_err;
struct i2c_msg *msgs;
int msgs_num;
int msg_write_idx;
u32 tx_buf_len;
u8 *tx_buf;
int msg_read_idx;
u32 rx_buf_len;
u8 *rx_buf;
int msg_err;
unsigned int status;
u32 abort_source;
int irq;
struct i2c_adapter adapter;
unsigned int tx_fifo_depth;
unsigned int rx_fifo_depth;
};
static u32
i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset)
{
/*
* DesignWare I2C core doesn't seem to have solid strategy to meet
* the tHD;STA timing spec. Configuring _HCNT based on tHIGH spec
* will result in violation of the tHD;STA spec.
*/
if (cond)
/*
* Conditional expression:
*
* IC_[FS]S_SCL_HCNT + (1+4+3) >= IC_CLK * tHIGH
*
* This is based on the DW manuals, and represents an ideal
* configuration. The resulting I2C bus speed will be
* faster than any of the others.
*
* If your hardware is free from tHD;STA issue, try this one.
*/
return (ic_clk * tSYMBOL + 5000) / 10000 - 8 + offset;
else
/*
* Conditional expression:
*
* IC_[FS]S_SCL_HCNT + 3 >= IC_CLK * (tHD;STA + tf)
*
* This is just experimental rule; the tHD;STA period turned
* out to be proportinal to (_HCNT + 3). With this setting,
* we could meet both tHIGH and tHD;STA timing specs.
*
* If unsure, you'd better to take this alternative.
*
* The reason why we need to take into account "tf" here,
* is the same as described in i2c_dw_scl_lcnt().
*/
return (ic_clk * (tSYMBOL + tf) + 5000) / 10000 - 3 + offset;
}
static u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset)
{
/*
* Conditional expression:
*
* IC_[FS]S_SCL_LCNT + 1 >= IC_CLK * (tLOW + tf)
*
* DW I2C core starts counting the SCL CNTs for the LOW period
* of the SCL clock (tLOW) as soon as it pulls the SCL line.
* In order to meet the tLOW timing spec, we need to take into
* account the fall time of SCL signal (tf). Default tf value
* should be 0.3 us, for safety.
*/
return ((ic_clk * (tLOW + tf) + 5000) / 10000) - 1 + offset;
}
/**
* 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 void i2c_dw_init(struct dw_i2c_dev *dev)
{
u32 input_clock_khz = clk_get_rate(dev->clk) / 1000;
u32 ic_con, hcnt, lcnt;
/* Disable the adapter */
writel(0, dev->base + DW_IC_ENABLE);
/* set standard and fast speed deviders for high/low periods */
/* Standard-mode */
hcnt = i2c_dw_scl_hcnt(input_clock_khz,
40, /* tHD;STA = tHIGH = 4.0 us */
3, /* tf = 0.3 us */
0, /* 0: DW default, 1: Ideal */
0); /* No offset */
lcnt = i2c_dw_scl_lcnt(input_clock_khz,
47, /* tLOW = 4.7 us */
3, /* tf = 0.3 us */
0); /* No offset */
writel(hcnt, dev->base + DW_IC_SS_SCL_HCNT);
writel(lcnt, dev->base + DW_IC_SS_SCL_LCNT);
dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
/* Fast-mode */
hcnt = i2c_dw_scl_hcnt(input_clock_khz,
6, /* tHD;STA = tHIGH = 0.6 us */
3, /* tf = 0.3 us */
0, /* 0: DW default, 1: Ideal */
0); /* No offset */
lcnt = i2c_dw_scl_lcnt(input_clock_khz,
13, /* tLOW = 1.3 us */
3, /* tf = 0.3 us */
0); /* No offset */
writel(hcnt, dev->base + DW_IC_FS_SCL_HCNT);
writel(lcnt, dev->base + DW_IC_FS_SCL_LCNT);
dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
/* Configure Tx/Rx FIFO threshold levels */
writel(dev->tx_fifo_depth - 1, dev->base + DW_IC_TX_TL);
writel(0, dev->base + DW_IC_RX_TL);
/* configure the i2c master */
ic_con = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
writel(ic_con, dev->base + DW_IC_CON);
}
/*
* Waiting for bus not busy
*/
static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
{
int timeout = TIMEOUT;
while (readl(dev->base + DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {
if (timeout <= 0) {
dev_warn(dev->dev, "timeout waiting for bus ready\n");
return -ETIMEDOUT;
}
timeout--;
mdelay(1);
}
return 0;
}
static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
{
struct i2c_msg *msgs = dev->msgs;
u32 ic_con;
/* Disable the adapter */
writel(0, dev->base + DW_IC_ENABLE);
/* set the slave (target) address */
writel(msgs[dev->msg_write_idx].addr, dev->base + DW_IC_TAR);
/* if the slave address is ten bit address, enable 10BITADDR */
ic_con = readl(dev->base + DW_IC_CON);
if (msgs[dev->msg_write_idx].flags & I2C_M_TEN)
ic_con |= DW_IC_CON_10BITADDR_MASTER;
else
ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
writel(ic_con, dev->base + DW_IC_CON);
/* Enable the adapter */
writel(1, dev->base + DW_IC_ENABLE);
/* Enable interrupts */
writel(DW_IC_INTR_DEFAULT_MASK, dev->base + 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;;
intr_mask = DW_IC_INTR_DEFAULT_MASK;
for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) {
/*
* 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;
}
tx_limit = dev->tx_fifo_depth - readl(dev->base + DW_IC_TXFLR);
rx_limit = dev->rx_fifo_depth - readl(dev->base + DW_IC_RXFLR);
while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) {
if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
writel(0x100, dev->base + DW_IC_DATA_CMD);
rx_limit--;
} else
writel(*buf++, dev->base + DW_IC_DATA_CMD);
tx_limit--; buf_len--;
}
dev->tx_buf = buf;
dev->tx_buf_len = buf_len;
if (buf_len > 0) {
/* 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;
writel(intr_mask, dev->base + DW_IC_INTR_MASK);
}
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 = readl(dev->base + DW_IC_RXFLR);
for (; len > 0 && rx_valid > 0; len--, rx_valid--)
*buf++ = readl(dev->base + DW_IC_DATA_CMD);
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;
}
}
static int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev)
{
unsigned long abort_source = dev->abort_source;
int i;
if (abort_source & DW_IC_TX_ABRT_NOACK) {
for_each_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
dev_dbg(dev->dev,
"%s: %s\n", __func__, abort_sources[i]);
return -EREMOTEIO;
}
for_each_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]);
if (abort_source & DW_IC_TX_ARB_LOST)
return -EAGAIN;
else if (abort_source & DW_IC_TX_ABRT_GCALL_READ)
return -EINVAL; /* wrong msgs[] data */
else
return -EIO;
}
/*
* 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);
mutex_lock(&dev->lock);
INIT_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;
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 */
ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, HZ);
if (ret == 0) {
dev_err(dev->dev, "controller timed out\n");
i2c_dw_init(dev);
ret = -ETIMEDOUT;
goto done;
} else if (ret < 0)
goto done;
if (dev->msg_err) {
ret = dev->msg_err;
goto done;
}
/* no error */
if (likely(!dev->cmd_err)) {
/* Disable the adapter */
writel(0, dev->base + DW_IC_ENABLE);
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;
}
ret = -EIO;
done:
mutex_unlock(&dev->lock);
return ret;
}
static u32 i2c_dw_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C |
I2C_FUNC_10BIT_ADDR |
I2C_FUNC_SMBUS_BYTE |
I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_WORD_DATA |
I2C_FUNC_SMBUS_I2C_BLOCK;
}
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 = 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.
*/
stat = readl(dev->base + 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
* readl(IC_INTR_STAT) to readl(IC_CLR_INTR).
*
* Instead, use the separately-prepared IC_CLR_* registers.
*/
if (stat & DW_IC_INTR_RX_UNDER)
readl(dev->base + DW_IC_CLR_RX_UNDER);
if (stat & DW_IC_INTR_RX_OVER)
readl(dev->base + DW_IC_CLR_RX_OVER);
if (stat & DW_IC_INTR_TX_OVER)
readl(dev->base + DW_IC_CLR_TX_OVER);
if (stat & DW_IC_INTR_RD_REQ)
readl(dev->base + 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 = readl(dev->base + DW_IC_TX_ABRT_SOURCE);
readl(dev->base + DW_IC_CLR_TX_ABRT);
}
if (stat & DW_IC_INTR_RX_DONE)
readl(dev->base + DW_IC_CLR_RX_DONE);
if (stat & DW_IC_INTR_ACTIVITY)
readl(dev->base + DW_IC_CLR_ACTIVITY);
if (stat & DW_IC_INTR_STOP_DET)
readl(dev->base + DW_IC_CLR_STOP_DET);
if (stat & DW_IC_INTR_START_DET)
readl(dev->base + DW_IC_CLR_START_DET);
if (stat & DW_IC_INTR_GEN_CALL)
readl(dev->base + DW_IC_CLR_GEN_CALL);
return stat;
}
/*
* Interrupt service routine. This gets called whenever an I2C interrupt
* occurs.
*/
static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
{
struct dw_i2c_dev *dev = dev_id;
u32 stat;
stat = i2c_dw_read_clear_intrbits(dev);
dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
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.
*/
writel(0, dev->base + 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);
return IRQ_HANDLED;
}
static struct i2c_algorithm i2c_dw_algo = {
.master_xfer = i2c_dw_xfer,
.functionality = i2c_dw_func,
};
static int __devinit dw_i2c_probe(struct platform_device *pdev)
{
struct dw_i2c_dev *dev;
struct i2c_adapter *adap;
struct resource *mem, *ioarea;
int irq, r;
/* NOTE: driver uses the static register mapping */
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!mem) {
dev_err(&pdev->dev, "no mem resource?\n");
return -EINVAL;
}
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "no irq resource?\n");
return irq; /* -ENXIO */
}
ioarea = request_mem_region(mem->start, resource_size(mem),
pdev->name);
if (!ioarea) {
dev_err(&pdev->dev, "I2C region already claimed\n");
return -EBUSY;
}
dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL);
if (!dev) {
r = -ENOMEM;
goto err_release_region;
}
init_completion(&dev->cmd_complete);
mutex_init(&dev->lock);
dev->dev = get_device(&pdev->dev);
dev->irq = irq;
platform_set_drvdata(pdev, dev);
dev->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(dev->clk)) {
r = -ENODEV;
goto err_free_mem;
}
clk_enable(dev->clk);
dev->base = ioremap(mem->start, resource_size(mem));
if (dev->base == NULL) {
dev_err(&pdev->dev, "failure mapping io resources\n");
r = -EBUSY;
goto err_unuse_clocks;
}
{
u32 param1 = readl(dev->base + DW_IC_COMP_PARAM_1);
dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1;
}
i2c_dw_init(dev);
writel(0, dev->base + DW_IC_INTR_MASK); /* disable IRQ */
r = request_irq(dev->irq, i2c_dw_isr, IRQF_DISABLED, pdev->name, dev);
if (r) {
dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
goto err_iounmap;
}
adap = &dev->adapter;
i2c_set_adapdata(adap, dev);
adap->owner = THIS_MODULE;
adap->class = I2C_CLASS_HWMON;
strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
sizeof(adap->name));
adap->algo = &i2c_dw_algo;
adap->dev.parent = &pdev->dev;
adap->nr = pdev->id;
r = i2c_add_numbered_adapter(adap);
if (r) {
dev_err(&pdev->dev, "failure adding adapter\n");
goto err_free_irq;
}
return 0;
err_free_irq:
free_irq(dev->irq, dev);
err_iounmap:
iounmap(dev->base);
err_unuse_clocks:
clk_disable(dev->clk);
clk_put(dev->clk);
dev->clk = NULL;
err_free_mem:
platform_set_drvdata(pdev, NULL);
put_device(&pdev->dev);
kfree(dev);
err_release_region:
release_mem_region(mem->start, resource_size(mem));
return r;
}
static int __devexit dw_i2c_remove(struct platform_device *pdev)
{
struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
struct resource *mem;
platform_set_drvdata(pdev, NULL);
i2c_del_adapter(&dev->adapter);
put_device(&pdev->dev);
clk_disable(dev->clk);
clk_put(dev->clk);
dev->clk = NULL;
writel(0, dev->base + DW_IC_ENABLE);
free_irq(dev->irq, dev);
kfree(dev);
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(mem->start, resource_size(mem));
return 0;
}
/* work with hotplug and coldplug */
MODULE_ALIAS("platform:i2c_designware");
static struct platform_driver dw_i2c_driver = {
.remove = __devexit_p(dw_i2c_remove),
.driver = {
.name = "i2c_designware",
.owner = THIS_MODULE,
},
};
static int __init dw_i2c_init_driver(void)
{
return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe);
}
module_init(dw_i2c_init_driver);
static void __exit dw_i2c_exit_driver(void)
{
platform_driver_unregister(&dw_i2c_driver);
}
module_exit(dw_i2c_exit_driver);
MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
MODULE_LICENSE("GPL");
