- 根目录:
- drivers
- i2c
- busses
- i2c-exynos5.c
/**
* i2c-exynos5.c - Samsung Exynos5 I2C Controller Driver
*
* Copyright (C) 2013 Samsung Electronics Co., Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/time.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/spinlock.h>
/*
* HSI2C controller from Samsung supports 2 modes of operation
* 1. Auto mode: Where in master automatically controls the whole transaction
* 2. Manual mode: Software controls the transaction by issuing commands
* START, READ, WRITE, STOP, RESTART in I2C_MANUAL_CMD register.
*
* Operation mode can be selected by setting AUTO_MODE bit in I2C_CONF register
*
* Special bits are available for both modes of operation to set commands
* and for checking transfer status
*/
/* Register Map */
#define HSI2C_CTL 0x00
#define HSI2C_FIFO_CTL 0x04
#define HSI2C_TRAILIG_CTL 0x08
#define HSI2C_CLK_CTL 0x0C
#define HSI2C_CLK_SLOT 0x10
#define HSI2C_INT_ENABLE 0x20
#define HSI2C_INT_STATUS 0x24
#define HSI2C_ERR_STATUS 0x2C
#define HSI2C_FIFO_STATUS 0x30
#define HSI2C_TX_DATA 0x34
#define HSI2C_RX_DATA 0x38
#define HSI2C_CONF 0x40
#define HSI2C_AUTO_CONF 0x44
#define HSI2C_TIMEOUT 0x48
#define HSI2C_MANUAL_CMD 0x4C
#define HSI2C_TRANS_STATUS 0x50
#define HSI2C_TIMING_HS1 0x54
#define HSI2C_TIMING_HS2 0x58
#define HSI2C_TIMING_HS3 0x5C
#define HSI2C_TIMING_FS1 0x60
#define HSI2C_TIMING_FS2 0x64
#define HSI2C_TIMING_FS3 0x68
#define HSI2C_TIMING_SLA 0x6C
#define HSI2C_ADDR 0x70
/* I2C_CTL Register bits */
#define HSI2C_FUNC_MODE_I2C (1u << 0)
#define HSI2C_MASTER (1u << 3)
#define HSI2C_RXCHON (1u << 6)
#define HSI2C_TXCHON (1u << 7)
#define HSI2C_SW_RST (1u << 31)
/* I2C_FIFO_CTL Register bits */
#define HSI2C_RXFIFO_EN (1u << 0)
#define HSI2C_TXFIFO_EN (1u << 1)
#define HSI2C_RXFIFO_TRIGGER_LEVEL(x) ((x) << 4)
#define HSI2C_TXFIFO_TRIGGER_LEVEL(x) ((x) << 16)
/* I2C_TRAILING_CTL Register bits */
#define HSI2C_TRAILING_COUNT (0xf)
/* I2C_INT_EN Register bits */
#define HSI2C_INT_TX_ALMOSTEMPTY_EN (1u << 0)
#define HSI2C_INT_RX_ALMOSTFULL_EN (1u << 1)
#define HSI2C_INT_TRAILING_EN (1u << 6)
/* I2C_INT_STAT Register bits */
#define HSI2C_INT_TX_ALMOSTEMPTY (1u << 0)
#define HSI2C_INT_RX_ALMOSTFULL (1u << 1)
#define HSI2C_INT_TX_UNDERRUN (1u << 2)
#define HSI2C_INT_TX_OVERRUN (1u << 3)
#define HSI2C_INT_RX_UNDERRUN (1u << 4)
#define HSI2C_INT_RX_OVERRUN (1u << 5)
#define HSI2C_INT_TRAILING (1u << 6)
#define HSI2C_INT_I2C (1u << 9)
#define HSI2C_INT_TRANS_DONE (1u << 7)
#define HSI2C_INT_TRANS_ABORT (1u << 8)
#define HSI2C_INT_NO_DEV_ACK (1u << 9)
#define HSI2C_INT_NO_DEV (1u << 10)
#define HSI2C_INT_TIMEOUT (1u << 11)
#define HSI2C_INT_I2C_TRANS (HSI2C_INT_TRANS_DONE | \
HSI2C_INT_TRANS_ABORT | \
HSI2C_INT_NO_DEV_ACK | \
HSI2C_INT_NO_DEV | \
HSI2C_INT_TIMEOUT)
/* I2C_FIFO_STAT Register bits */
#define HSI2C_RX_FIFO_EMPTY (1u << 24)
#define HSI2C_RX_FIFO_FULL (1u << 23)
#define HSI2C_RX_FIFO_LVL(x) ((x >> 16) & 0x7f)
#define HSI2C_TX_FIFO_EMPTY (1u << 8)
#define HSI2C_TX_FIFO_FULL (1u << 7)
#define HSI2C_TX_FIFO_LVL(x) ((x >> 0) & 0x7f)
/* I2C_CONF Register bits */
#define HSI2C_AUTO_MODE (1u << 31)
#define HSI2C_10BIT_ADDR_MODE (1u << 30)
#define HSI2C_HS_MODE (1u << 29)
/* I2C_AUTO_CONF Register bits */
#define HSI2C_READ_WRITE (1u << 16)
#define HSI2C_STOP_AFTER_TRANS (1u << 17)
#define HSI2C_MASTER_RUN (1u << 31)
/* I2C_TIMEOUT Register bits */
#define HSI2C_TIMEOUT_EN (1u << 31)
#define HSI2C_TIMEOUT_MASK 0xff
/* I2C_TRANS_STATUS register bits */
#define HSI2C_MASTER_BUSY (1u << 17)
#define HSI2C_SLAVE_BUSY (1u << 16)
#define HSI2C_TIMEOUT_AUTO (1u << 4)
#define HSI2C_NO_DEV (1u << 3)
#define HSI2C_NO_DEV_ACK (1u << 2)
#define HSI2C_TRANS_ABORT (1u << 1)
#define HSI2C_TRANS_DONE (1u << 0)
/* I2C_ADDR register bits */
#define HSI2C_SLV_ADDR_SLV(x) ((x & 0x3ff) << 0)
#define HSI2C_SLV_ADDR_MAS(x) ((x & 0x3ff) << 10)
#define HSI2C_MASTER_ID(x) ((x & 0xff) << 24)
#define MASTER_ID(x) ((x & 0x7) + 0x08)
/*
* Controller operating frequency, timing values for operation
* are calculated against this frequency
*/
#define HSI2C_HS_TX_CLOCK 1000000
#define HSI2C_FS_TX_CLOCK 100000
#define HSI2C_HIGH_SPD 1
#define HSI2C_FAST_SPD 0
#define EXYNOS5_I2C_TIMEOUT (msecs_to_jiffies(1000))
#define HSI2C_EXYNOS7 BIT(0)
struct exynos5_i2c {
struct i2c_adapter adap;
unsigned int suspended:1;
struct i2c_msg *msg;
struct completion msg_complete;
unsigned int msg_ptr;
unsigned int irq;
void __iomem *regs;
struct clk *clk;
struct device *dev;
int state;
spinlock_t lock; /* IRQ synchronization */
/*
* Since the TRANS_DONE bit is cleared on read, and we may read it
* either during an IRQ or after a transaction, keep track of its
* state here.
*/
int trans_done;
/* Controller operating frequency */
unsigned int fs_clock;
unsigned int hs_clock;
/*
* HSI2C Controller can operate in
* 1. High speed upto 3.4Mbps
* 2. Fast speed upto 1Mbps
*/
int speed_mode;
/* Version of HS-I2C Hardware */
struct exynos_hsi2c_variant *variant;
};
/**
* struct exynos_hsi2c_variant - platform specific HSI2C driver data
* @fifo_depth: the fifo depth supported by the HSI2C module
*
* Specifies platform specific configuration of HSI2C module.
* Note: A structure for driver specific platform data is used for future
* expansion of its usage.
*/
struct exynos_hsi2c_variant {
unsigned int fifo_depth;
unsigned int hw;
};
static const struct exynos_hsi2c_variant exynos5250_hsi2c_data = {
.fifo_depth = 64,
};
static const struct exynos_hsi2c_variant exynos5260_hsi2c_data = {
.fifo_depth = 16,
};
static const struct exynos_hsi2c_variant exynos7_hsi2c_data = {
.fifo_depth = 16,
.hw = HSI2C_EXYNOS7,
};
static const struct of_device_id exynos5_i2c_match[] = {
{
.compatible = "samsung,exynos5-hsi2c",
.data = &exynos5250_hsi2c_data
}, {
.compatible = "samsung,exynos5250-hsi2c",
.data = &exynos5250_hsi2c_data
}, {
.compatible = "samsung,exynos5260-hsi2c",
.data = &exynos5260_hsi2c_data
}, {
.compatible = "samsung,exynos7-hsi2c",
.data = &exynos7_hsi2c_data
}, {},
};
MODULE_DEVICE_TABLE(of, exynos5_i2c_match);
static inline struct exynos_hsi2c_variant *exynos5_i2c_get_variant
(struct platform_device *pdev)
{
const struct of_device_id *match;
match = of_match_node(exynos5_i2c_match, pdev->dev.of_node);
return (struct exynos_hsi2c_variant *)match->data;
}
static void exynos5_i2c_clr_pend_irq(struct exynos5_i2c *i2c)
{
writel(readl(i2c->regs + HSI2C_INT_STATUS),
i2c->regs + HSI2C_INT_STATUS);
}
/*
* exynos5_i2c_set_timing: updates the registers with appropriate
* timing values calculated
*
* Returns 0 on success, -EINVAL if the cycle length cannot
* be calculated.
*/
static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, int mode)
{
u32 i2c_timing_s1;
u32 i2c_timing_s2;
u32 i2c_timing_s3;
u32 i2c_timing_sla;
unsigned int t_start_su, t_start_hd;
unsigned int t_stop_su;
unsigned int t_data_su, t_data_hd;
unsigned int t_scl_l, t_scl_h;
unsigned int t_sr_release;
unsigned int t_ftl_cycle;
unsigned int clkin = clk_get_rate(i2c->clk);
unsigned int div, utemp0 = 0, utemp1 = 0, clk_cycle;
unsigned int op_clk = (mode == HSI2C_HIGH_SPD) ?
i2c->hs_clock : i2c->fs_clock;
/*
* In case of HSI2C controller in Exynos5 series
* FPCLK / FI2C =
* (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + 2 * FLT_CYCLE
*
* In case of HSI2C controllers in Exynos7 series
* FPCLK / FI2C =
* (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + FLT_CYCLE
*
* utemp0 = (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2)
* utemp1 = (TSCLK_L + TSCLK_H + 2)
*/
t_ftl_cycle = (readl(i2c->regs + HSI2C_CONF) >> 16) & 0x7;
utemp0 = (clkin / op_clk) - 8;
if (i2c->variant->hw == HSI2C_EXYNOS7)
utemp0 -= t_ftl_cycle;
else
utemp0 -= 2 * t_ftl_cycle;
/* CLK_DIV max is 256 */
for (div = 0; div < 256; div++) {
utemp1 = utemp0 / (div + 1);
/*
* SCL_L and SCL_H each has max value of 255
* Hence, For the clk_cycle to the have right value
* utemp1 has to be less then 512 and more than 4.
*/
if ((utemp1 < 512) && (utemp1 > 4)) {
clk_cycle = utemp1 - 2;
break;
} else if (div == 255) {
dev_warn(i2c->dev, "Failed to calculate divisor");
return -EINVAL;
}
}
t_scl_l = clk_cycle / 2;
t_scl_h = clk_cycle / 2;
t_start_su = t_scl_l;
t_start_hd = t_scl_l;
t_stop_su = t_scl_l;
t_data_su = t_scl_l / 2;
t_data_hd = t_scl_l / 2;
t_sr_release = clk_cycle;
i2c_timing_s1 = t_start_su << 24 | t_start_hd << 16 | t_stop_su << 8;
i2c_timing_s2 = t_data_su << 24 | t_scl_l << 8 | t_scl_h << 0;
i2c_timing_s3 = div << 16 | t_sr_release << 0;
i2c_timing_sla = t_data_hd << 0;
dev_dbg(i2c->dev, "tSTART_SU: %X, tSTART_HD: %X, tSTOP_SU: %X\n",
t_start_su, t_start_hd, t_stop_su);
dev_dbg(i2c->dev, "tDATA_SU: %X, tSCL_L: %X, tSCL_H: %X\n",
t_data_su, t_scl_l, t_scl_h);
dev_dbg(i2c->dev, "nClkDiv: %X, tSR_RELEASE: %X\n",
div, t_sr_release);
dev_dbg(i2c->dev, "tDATA_HD: %X\n", t_data_hd);
if (mode == HSI2C_HIGH_SPD) {
writel(i2c_timing_s1, i2c->regs + HSI2C_TIMING_HS1);
writel(i2c_timing_s2, i2c->regs + HSI2C_TIMING_HS2);
writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_HS3);
} else {
writel(i2c_timing_s1, i2c->regs + HSI2C_TIMING_FS1);
writel(i2c_timing_s2, i2c->regs + HSI2C_TIMING_FS2);
writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_FS3);
}
writel(i2c_timing_sla, i2c->regs + HSI2C_TIMING_SLA);
return 0;
}
static int exynos5_hsi2c_clock_setup(struct exynos5_i2c *i2c)
{
/*
* Configure the Fast speed timing values
* Even the High Speed mode initially starts with Fast mode
*/
if (exynos5_i2c_set_timing(i2c, HSI2C_FAST_SPD)) {
dev_err(i2c->dev, "HSI2C FS Clock set up failed\n");
return -EINVAL;
}
/* configure the High speed timing values */
if (i2c->speed_mode == HSI2C_HIGH_SPD) {
if (exynos5_i2c_set_timing(i2c, HSI2C_HIGH_SPD)) {
dev_err(i2c->dev, "HSI2C HS Clock set up failed\n");
return -EINVAL;
}
}
return 0;
}
/*
* exynos5_i2c_init: configures the controller for I2C functionality
* Programs I2C controller for Master mode operation
*/
static void exynos5_i2c_init(struct exynos5_i2c *i2c)
{
u32 i2c_conf = readl(i2c->regs + HSI2C_CONF);
u32 i2c_timeout = readl(i2c->regs + HSI2C_TIMEOUT);
/* Clear to disable Timeout */
i2c_timeout &= ~HSI2C_TIMEOUT_EN;
writel(i2c_timeout, i2c->regs + HSI2C_TIMEOUT);
writel((HSI2C_FUNC_MODE_I2C | HSI2C_MASTER),
i2c->regs + HSI2C_CTL);
writel(HSI2C_TRAILING_COUNT, i2c->regs + HSI2C_TRAILIG_CTL);
if (i2c->speed_mode == HSI2C_HIGH_SPD) {
writel(HSI2C_MASTER_ID(MASTER_ID(i2c->adap.nr)),
i2c->regs + HSI2C_ADDR);
i2c_conf |= HSI2C_HS_MODE;
}
writel(i2c_conf | HSI2C_AUTO_MODE, i2c->regs + HSI2C_CONF);
}
static void exynos5_i2c_reset(struct exynos5_i2c *i2c)
{
u32 i2c_ctl;
/* Set and clear the bit for reset */
i2c_ctl = readl(i2c->regs + HSI2C_CTL);
i2c_ctl |= HSI2C_SW_RST;
writel(i2c_ctl, i2c->regs + HSI2C_CTL);
i2c_ctl = readl(i2c->regs + HSI2C_CTL);
i2c_ctl &= ~HSI2C_SW_RST;
writel(i2c_ctl, i2c->regs + HSI2C_CTL);
/* We don't expect calculations to fail during the run */
exynos5_hsi2c_clock_setup(i2c);
/* Initialize the configure registers */
exynos5_i2c_init(i2c);
}
/*
* exynos5_i2c_irq: top level IRQ servicing routine
*
* INT_STATUS registers gives the interrupt details. Further,
* FIFO_STATUS or TRANS_STATUS registers are to be check for detailed
* state of the bus.
*/
static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id)
{
struct exynos5_i2c *i2c = dev_id;
u32 fifo_level, int_status, fifo_status, trans_status;
unsigned char byte;
int len = 0;
i2c->state = -EINVAL;
spin_lock(&i2c->lock);
int_status = readl(i2c->regs + HSI2C_INT_STATUS);
writel(int_status, i2c->regs + HSI2C_INT_STATUS);
/* handle interrupt related to the transfer status */
if (i2c->variant->hw == HSI2C_EXYNOS7) {
if (int_status & HSI2C_INT_TRANS_DONE) {
i2c->trans_done = 1;
i2c->state = 0;
} else if (int_status & HSI2C_INT_TRANS_ABORT) {
dev_dbg(i2c->dev, "Deal with arbitration lose\n");
i2c->state = -EAGAIN;
goto stop;
} else if (int_status & HSI2C_INT_NO_DEV_ACK) {
dev_dbg(i2c->dev, "No ACK from device\n");
i2c->state = -ENXIO;
goto stop;
} else if (int_status & HSI2C_INT_NO_DEV) {
dev_dbg(i2c->dev, "No device\n");
i2c->state = -ENXIO;
goto stop;
} else if (int_status & HSI2C_INT_TIMEOUT) {
dev_dbg(i2c->dev, "Accessing device timed out\n");
i2c->state = -ETIMEDOUT;
goto stop;
}
} else if (int_status & HSI2C_INT_I2C) {
trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS);
if (trans_status & HSI2C_NO_DEV_ACK) {
dev_dbg(i2c->dev, "No ACK from device\n");
i2c->state = -ENXIO;
goto stop;
} else if (trans_status & HSI2C_NO_DEV) {
dev_dbg(i2c->dev, "No device\n");
i2c->state = -ENXIO;
goto stop;
} else if (trans_status & HSI2C_TRANS_ABORT) {
dev_dbg(i2c->dev, "Deal with arbitration lose\n");
i2c->state = -EAGAIN;
goto stop;
} else if (trans_status & HSI2C_TIMEOUT_AUTO) {
dev_dbg(i2c->dev, "Accessing device timed out\n");
i2c->state = -ETIMEDOUT;
goto stop;
} else if (trans_status & HSI2C_TRANS_DONE) {
i2c->trans_done = 1;
i2c->state = 0;
}
}
if ((i2c->msg->flags & I2C_M_RD) && (int_status &
(HSI2C_INT_TRAILING | HSI2C_INT_RX_ALMOSTFULL))) {
fifo_status = readl(i2c->regs + HSI2C_FIFO_STATUS);
fifo_level = HSI2C_RX_FIFO_LVL(fifo_status);
len = min(fifo_level, i2c->msg->len - i2c->msg_ptr);
while (len > 0) {
byte = (unsigned char)
readl(i2c->regs + HSI2C_RX_DATA);
i2c->msg->buf[i2c->msg_ptr++] = byte;
len--;
}
i2c->state = 0;
} else if (int_status & HSI2C_INT_TX_ALMOSTEMPTY) {
fifo_status = readl(i2c->regs + HSI2C_FIFO_STATUS);
fifo_level = HSI2C_TX_FIFO_LVL(fifo_status);
len = i2c->variant->fifo_depth - fifo_level;
if (len > (i2c->msg->len - i2c->msg_ptr))
len = i2c->msg->len - i2c->msg_ptr;
while (len > 0) {
byte = i2c->msg->buf[i2c->msg_ptr++];
writel(byte, i2c->regs + HSI2C_TX_DATA);
len--;
}
i2c->state = 0;
}
stop:
if ((i2c->trans_done && (i2c->msg->len == i2c->msg_ptr)) ||
(i2c->state < 0)) {
writel(0, i2c->regs + HSI2C_INT_ENABLE);
exynos5_i2c_clr_pend_irq(i2c);
complete(&i2c->msg_complete);
}
spin_unlock(&i2c->lock);
return IRQ_HANDLED;
}
/*
* exynos5_i2c_wait_bus_idle
*
* Wait for the bus to go idle, indicated by the MASTER_BUSY bit being
* cleared.
*
* Returns -EBUSY if the bus cannot be bought to idle
*/
static int exynos5_i2c_wait_bus_idle(struct exynos5_i2c *i2c)
{
unsigned long stop_time;
u32 trans_status;
/* wait for 100 milli seconds for the bus to be idle */
stop_time = jiffies + msecs_to_jiffies(100) + 1;
do {
trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS);
if (!(trans_status & HSI2C_MASTER_BUSY))
return 0;
usleep_range(50, 200);
} while (time_before(jiffies, stop_time));
return -EBUSY;
}
/*
* exynos5_i2c_message_start: Configures the bus and starts the xfer
* i2c: struct exynos5_i2c pointer for the current bus
* stop: Enables stop after transfer if set. Set for last transfer of
* in the list of messages.
*
* Configures the bus for read/write function
* Sets chip address to talk to, message length to be sent.
* Enables appropriate interrupts and sends start xfer command.
*/
static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, int stop)
{
u32 i2c_ctl;
u32 int_en = 0;
u32 i2c_auto_conf = 0;
u32 fifo_ctl;
unsigned long flags;
unsigned short trig_lvl;
if (i2c->variant->hw == HSI2C_EXYNOS7)
int_en |= HSI2C_INT_I2C_TRANS;
else
int_en |= HSI2C_INT_I2C;
i2c_ctl = readl(i2c->regs + HSI2C_CTL);
i2c_ctl &= ~(HSI2C_TXCHON | HSI2C_RXCHON);
fifo_ctl = HSI2C_RXFIFO_EN | HSI2C_TXFIFO_EN;
if (i2c->msg->flags & I2C_M_RD) {
i2c_ctl |= HSI2C_RXCHON;
i2c_auto_conf |= HSI2C_READ_WRITE;
trig_lvl = (i2c->msg->len > i2c->variant->fifo_depth) ?
(i2c->variant->fifo_depth * 3 / 4) : i2c->msg->len;
fifo_ctl |= HSI2C_RXFIFO_TRIGGER_LEVEL(trig_lvl);
int_en |= (HSI2C_INT_RX_ALMOSTFULL_EN |
HSI2C_INT_TRAILING_EN);
} else {
i2c_ctl |= HSI2C_TXCHON;
trig_lvl = (i2c->msg->len > i2c->variant->fifo_depth) ?
(i2c->variant->fifo_depth * 1 / 4) : i2c->msg->len;
fifo_ctl |= HSI2C_TXFIFO_TRIGGER_LEVEL(trig_lvl);
int_en |= HSI2C_INT_TX_ALMOSTEMPTY_EN;
}
writel(HSI2C_SLV_ADDR_MAS(i2c->msg->addr), i2c->regs + HSI2C_ADDR);
writel(fifo_ctl, i2c->regs + HSI2C_FIFO_CTL);
writel(i2c_ctl, i2c->regs + HSI2C_CTL);
/*
* Enable interrupts before starting the transfer so that we don't
* miss any INT_I2C interrupts.
*/
spin_lock_irqsave(&i2c->lock, flags);
writel(int_en, i2c->regs + HSI2C_INT_ENABLE);
if (stop == 1)
i2c_auto_conf |= HSI2C_STOP_AFTER_TRANS;
i2c_auto_conf |= i2c->msg->len;
i2c_auto_conf |= HSI2C_MASTER_RUN;
writel(i2c_auto_conf, i2c->regs + HSI2C_AUTO_CONF);
spin_unlock_irqrestore(&i2c->lock, flags);
}
static int exynos5_i2c_xfer_msg(struct exynos5_i2c *i2c,
struct i2c_msg *msgs, int stop)
{
unsigned long timeout;
int ret;
i2c->msg = msgs;
i2c->msg_ptr = 0;
i2c->trans_done = 0;
reinit_completion(&i2c->msg_complete);
exynos5_i2c_message_start(i2c, stop);
timeout = wait_for_completion_timeout(&i2c->msg_complete,
EXYNOS5_I2C_TIMEOUT);
if (timeout == 0)
ret = -ETIMEDOUT;
else
ret = i2c->state;
/*
* If this is the last message to be transfered (stop == 1)
* Then check if the bus can be brought back to idle.
*/
if (ret == 0 && stop)
ret = exynos5_i2c_wait_bus_idle(i2c);
if (ret < 0) {
exynos5_i2c_reset(i2c);
if (ret == -ETIMEDOUT)
dev_warn(i2c->dev, "%s timeout\n",
(msgs->flags & I2C_M_RD) ? "rx" : "tx");
}
/* Return the state as in interrupt routine */
return ret;
}
static int exynos5_i2c_xfer(struct i2c_adapter *adap,
struct i2c_msg *msgs, int num)
{
struct exynos5_i2c *i2c = adap->algo_data;
int i = 0, ret = 0, stop = 0;
if (i2c->suspended) {
dev_err(i2c->dev, "HS-I2C is not initialized.\n");
return -EIO;
}
clk_prepare_enable(i2c->clk);
for (i = 0; i < num; i++, msgs++) {
stop = (i == num - 1);
ret = exynos5_i2c_xfer_msg(i2c, msgs, stop);
if (ret < 0)
goto out;
}
if (i == num) {
ret = num;
} else {
/* Only one message, cannot access the device */
if (i == 1)
ret = -EREMOTEIO;
else
ret = i;
dev_warn(i2c->dev, "xfer message failed\n");
}
out:
clk_disable_unprepare(i2c->clk);
return ret;
}
static u32 exynos5_i2c_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
}
static const struct i2c_algorithm exynos5_i2c_algorithm = {
.master_xfer = exynos5_i2c_xfer,
.functionality = exynos5_i2c_func,
};
static int exynos5_i2c_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct exynos5_i2c *i2c;
struct resource *mem;
unsigned int op_clock;
int ret;
i2c = devm_kzalloc(&pdev->dev, sizeof(struct exynos5_i2c), GFP_KERNEL);
if (!i2c)
return -ENOMEM;
if (of_property_read_u32(np, "clock-frequency", &op_clock)) {
i2c->speed_mode = HSI2C_FAST_SPD;
i2c->fs_clock = HSI2C_FS_TX_CLOCK;
} else {
if (op_clock >= HSI2C_HS_TX_CLOCK) {
i2c->speed_mode = HSI2C_HIGH_SPD;
i2c->fs_clock = HSI2C_FS_TX_CLOCK;
i2c->hs_clock = op_clock;
} else {
i2c->speed_mode = HSI2C_FAST_SPD;
i2c->fs_clock = op_clock;
}
}
strlcpy(i2c->adap.name, "exynos5-i2c", sizeof(i2c->adap.name));
i2c->adap.owner = THIS_MODULE;
i2c->adap.algo = &exynos5_i2c_algorithm;
i2c->adap.retries = 3;
i2c->dev = &pdev->dev;
i2c->clk = devm_clk_get(&pdev->dev, "hsi2c");
if (IS_ERR(i2c->clk)) {
dev_err(&pdev->dev, "cannot get clock\n");
return -ENOENT;
}
clk_prepare_enable(i2c->clk);
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
i2c->regs = devm_ioremap_resource(&pdev->dev, mem);
if (IS_ERR(i2c->regs)) {
ret = PTR_ERR(i2c->regs);
goto err_clk;
}
i2c->adap.dev.of_node = np;
i2c->adap.algo_data = i2c;
i2c->adap.dev.parent = &pdev->dev;
/* Clear pending interrupts from u-boot or misc causes */
exynos5_i2c_clr_pend_irq(i2c);
spin_lock_init(&i2c->lock);
init_completion(&i2c->msg_complete);
i2c->irq = ret = platform_get_irq(pdev, 0);
if (ret <= 0) {
dev_err(&pdev->dev, "cannot find HS-I2C IRQ\n");
ret = -EINVAL;
goto err_clk;
}
ret = devm_request_irq(&pdev->dev, i2c->irq, exynos5_i2c_irq,
IRQF_NO_SUSPEND | IRQF_ONESHOT,
dev_name(&pdev->dev), i2c);
if (ret != 0) {
dev_err(&pdev->dev, "cannot request HS-I2C IRQ %d\n", i2c->irq);
goto err_clk;
}
/* Need to check the variant before setting up. */
i2c->variant = exynos5_i2c_get_variant(pdev);
ret = exynos5_hsi2c_clock_setup(i2c);
if (ret)
goto err_clk;
exynos5_i2c_reset(i2c);
ret = i2c_add_adapter(&i2c->adap);
if (ret < 0) {
dev_err(&pdev->dev, "failed to add bus to i2c core\n");
goto err_clk;
}
platform_set_drvdata(pdev, i2c);
err_clk:
clk_disable_unprepare(i2c->clk);
return ret;
}
static int exynos5_i2c_remove(struct platform_device *pdev)
{
struct exynos5_i2c *i2c = platform_get_drvdata(pdev);
i2c_del_adapter(&i2c->adap);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int exynos5_i2c_suspend_noirq(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct exynos5_i2c *i2c = platform_get_drvdata(pdev);
i2c->suspended = 1;
return 0;
}
static int exynos5_i2c_resume_noirq(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct exynos5_i2c *i2c = platform_get_drvdata(pdev);
int ret = 0;
clk_prepare_enable(i2c->clk);
ret = exynos5_hsi2c_clock_setup(i2c);
if (ret) {
clk_disable_unprepare(i2c->clk);
return ret;
}
exynos5_i2c_init(i2c);
clk_disable_unprepare(i2c->clk);
i2c->suspended = 0;
return 0;
}
#endif
static const struct dev_pm_ops exynos5_i2c_dev_pm_ops = {
#ifdef CONFIG_PM_SLEEP
.suspend_noirq = exynos5_i2c_suspend_noirq,
.resume_noirq = exynos5_i2c_resume_noirq,
.freeze_noirq = exynos5_i2c_suspend_noirq,
.thaw_noirq = exynos5_i2c_resume_noirq,
.poweroff_noirq = exynos5_i2c_suspend_noirq,
.restore_noirq = exynos5_i2c_resume_noirq,
#endif
};
static struct platform_driver exynos5_i2c_driver = {
.probe = exynos5_i2c_probe,
.remove = exynos5_i2c_remove,
.driver = {
.name = "exynos5-hsi2c",
.pm = &exynos5_i2c_dev_pm_ops,
.of_match_table = exynos5_i2c_match,
},
};
module_platform_driver(exynos5_i2c_driver);
MODULE_DESCRIPTION("Exynos5 HS-I2C Bus driver");
MODULE_AUTHOR("Naveen Krishna Chatradhi, <ch.naveen@samsung.com>");
MODULE_AUTHOR("Taekgyun Ko, <taeggyun.ko@samsung.com>");
MODULE_LICENSE("GPL v2");