Add delay after setting the STOP bit in i2c control register
Signed-off-by: Konstantin Porotchkin <[email protected]>
---
drivers/i2c/busses/i2c-mv64xxx.c | 25 +++++++++++++++++++++++++
include/linux/mv643xx_i2c.h | 1 +
2 files changed, 26 insertions(+), 0 deletions(-)
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index d013e25..a6e9a3f 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -99,6 +99,7 @@ struct mv64xxx_i2c_data {
int rc;
u32 freq_m;
u32 freq_n;
+ u32 delay_after_stop;
int irq_disabled;
wait_queue_head_t waitq;
spinlock_t lock;
@@ -114,6 +115,25 @@ struct mv64xxx_i2c_data {
*****************************************************************************
*/
+static void
+mv64xxx_i2c_wait_after_stop(struct mv64xxx_i2c_data *drv_data)
+{
+ int i = 0;
+
+ udelay(drv_data->delay_after_stop);
+
+ /* wait for the stop bit up to 100 usec more */
+ while (readl(drv_data->reg_base + MV64XXX_I2C_REG_CONTROL) &
+ MV64XXX_I2C_REG_CONTROL_STOP){
+ udelay(1);
+ if (i++ > 100) {
+ dev_err(&drv_data->adapter.dev,
+ " I2C bus locked, stop bit not cleared\n");
+ break;
+ }
+ }
+
+}
/* Reset hardware and initialize FSM */
static void
mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data)
@@ -125,6 +145,7 @@ mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data)
writel(0, drv_data->reg_base + MV64XXX_I2C_REG_EXT_SLAVE_ADDR);
writel(MV64XXX_I2C_REG_CONTROL_TWSIEN | MV64XXX_I2C_REG_CONTROL_STOP,
drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
+ mv64xxx_i2c_wait_after_stop(drv_data);
drv_data->state = MV64XXX_I2C_STATE_IDLE;
}
@@ -299,6 +320,7 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
+ mv64xxx_i2c_wait_after_stop(drv_data);
drv_data->block = 0;
wake_up_interruptible(&drv_data->waitq);
break;
@@ -314,6 +336,7 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
+ mv64xxx_i2c_wait_after_stop(drv_data);
drv_data->block = 0;
wake_up_interruptible(&drv_data->waitq);
break;
@@ -558,6 +581,8 @@ mv64xxx_i2c_probe(struct platform_device *pd)
drv_data->freq_m = pdata->freq_m;
drv_data->freq_n = pdata->freq_n;
+ drv_data->delay_after_stop = pdata->delay_after_stop ?
+ pdata->delay_after_stop : 10;
drv_data->irq = platform_get_irq(pd, 0);
if (drv_data->irq < 0) {
rc = -ENXIO;
diff --git a/include/linux/mv643xx_i2c.h b/include/linux/mv643xx_i2c.h
index 5db5152..6d151c4 100644
--- a/include/linux/mv643xx_i2c.h
+++ b/include/linux/mv643xx_i2c.h
@@ -16,6 +16,7 @@
struct mv64xxx_i2c_pdata {
u32 freq_m;
u32 freq_n;
+ u32 delay_after_stop;
u32 timeout; /* In milliseconds */
};
--
1.7.4.1
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