iio: exynos_adc: reduce timeout and use wait_for_completion_timeout

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>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c
index 9d296094892dda95e7c6ce2504599fe2a6b96a4d..a1f6d90f3d269580678bc29c1705866c14ef950c 100644 (file)
--- 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)