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.antipov@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;
-
Dmitry Antipov