[PATCH 3/5 v3] iio: exynos_adc: reduce timeout and use wait_for_completion_timeout

Naveen Krishna Chatradhi
2014-04-30T09:30:03Z

ADC module on Exynos5 SoCs runs at 600KSPS. At this conversion rate,
waiting for 1000 msecs is wasteful (incase of h/w failure).

Hence, reduce the time out to 100msecs and use
wait_for_completion_timeout() instead of
wait_for_completion_interruptible_timeout()

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Reviewed-by: Doug Anderson <dianders@chromium.org>
---
Changes since v2:
None
Changes since v1:
None
v0:
This change is a part of the patch reviewd at https://lkml.org/lkml/2013/11/5/92

drivers/iio/adc/exynos_adc.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c
index ff98c5d..939aaf7 100644
--- a/drivers/iio/adc/exynos_adc.c
+++ b/drivers/iio/adc/exynos_adc.c
@@ -82,7 +82,7 @@ enum adc_version {
#define ADC_CON_EN_START (1u << 0)
#define ADC_DATX_MASK 0xFFF

-#define EXYNOS_ADC_TIMEOUT (msecs_to_jiffies(1000))
+#define EXYNOS_ADC_TIMEOUT (msecs_to_jiffies(100))

struct exynos_adc {
void __iomem *regs;
@@ -121,6 +121,7 @@ static int exynos_read_raw(struct iio_dev *indio_dev,
struct exynos_adc *info = iio_priv(indio_dev);
unsigned long timeout;
u32 con1, con2;
+ int ret;

if (mask != IIO_CHAN_INFO_RAW)
return -EINVAL;
@@ -145,16 +146,19 @@ static int exynos_read_raw(struct iio_dev *indio_dev,
ADC_V1_CON(info->regs));
}

- timeout = wait_for_completion_interruptible_timeout
+ timeout = wait_for_completion_timeout
(&info->completion, EXYNOS_ADC_TIMEOUT);
- *val = info->value;
+ if (timeout == 0) {
+ ret = -ETIMEDOUT;
+ } else {
+ *val = info->value;
+ *val2 = 0;
+ ret = IIO_VAL_INT;
+ }

mutex_unlock(&indio_dev->mlock);

- if (timeout == 0)
- return -ETIMEDOUT;
-
- return IIO_VAL_INT;
+ return ret;
}

static irqreturn_t exynos_adc_isr(int irq, void *dev_id)
--
1.7.9.5