Use usleep_range() with return value to implement time-bounded
wait-for hardware loop where delay is applicable; use ktime
instead of jiffies for a busy-wait loop.
Signed-off-by: Dmitry Antipov <dmitry.anti...@linaro.org>
---
drivers/i2c/busses/i2c-omap.c | 23 +++++++++++------------
1 files changed, 11 insertions(+), 12 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index fa23faa..401a622 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -49,8 +49,8 @@
#define OMAP_I2C_REV_ON_3430 0x3C
#define OMAP_I2C_REV_ON_3530_4430 0x40
-/* timeout waiting for the controller to respond */
-#define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
+/* timeout waiting for the controller to respond, in usecs */
+#define OMAP_I2C_TIMEOUT USEC_PER_SEC
/* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */
enum {
@@ -333,16 +333,16 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK);
/* For some reason we need to set the EN bit before the
* reset done bit gets set. */
- timeout = jiffies + OMAP_I2C_TIMEOUT;
+ timeout = 0;
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG) &
SYSS_RESETDONE_MASK)) {
- if (time_after(jiffies, timeout)) {
+ if (timeout > OMAP_I2C_TIMEOUT) {
dev_warn(dev->dev, "timeout waiting "
"for controller reset\n");
return -ETIMEDOUT;
}
- msleep(1);
+ timeout += usleep_range(1000, 2000);
}
/* SYSC register is cleared by the reset; rewrite it */
@@ -498,15 +498,14 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
*/
static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev)
{
- unsigned long timeout;
+ unsigned long timeout = 0;
- timeout = jiffies + OMAP_I2C_TIMEOUT;
while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
- if (time_after(jiffies, timeout)) {
+ if (timeout > OMAP_I2C_TIMEOUT) {
dev_warn(dev->dev, "timeout waiting for bus ready\n");
return -ETIMEDOUT;
}
- msleep(1);
+ timeout += usleep_range(1000, 2000);
}
return 0;
@@ -564,13 +563,13 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
* Don't write stt and stp together on some hardware.
*/
if (dev->b_hw && stop) {
- unsigned long delay = jiffies + OMAP_I2C_TIMEOUT;
+ ktime_t start = ktime_get();
u16 con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
while (con & OMAP_I2C_CON_STT) {
con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
/* Let the user know if i2c is in a bad state */
- if (time_after(jiffies, delay)) {
+ if (ktime_us_delta(ktime_get(), start) >
OMAP_I2C_TIMEOUT) {
dev_err(dev->dev, "controller timed out "
"waiting for start condition to finish\n");
return -ETIMEDOUT;
@@ -588,7 +587,7 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
* into arbitration and we're currently unable to recover from it.
*/
r = wait_for_completion_timeout(&dev->cmd_complete,
- OMAP_I2C_TIMEOUT);
+ usecs_to_jiffies(OMAP_I2C_TIMEOUT));
dev->buf_len = 0;
if (r < 0)
return r;
--
1.7.7.5
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