iio: dac: ad5446: Make use of the cleanup helpers

Use the auto unlocking helpers from cleanup.h. Allows for some code
simplification.

While at it, don't use the ternary operator in
ad5446_write_dac_powerdown() and add an helper function to write the DAC
code. The reason for the function was purely to avoid having to use
unreachable().

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/dac/ad5446.c b/drivers/iio/dac/ad5446.c
index 59e1f67ef3342ee4f481187f94127751a093a7eb..1943e801499027bbe15201fe22ee56447e6a3351 100644 (file)
--- a/drivers/iio/dac/ad5446.c
+++ b/drivers/iio/dac/ad5446.c
@@ -5,6 +5,7 @@
  * Copyright 2010 Analog Devices Inc.
  */
 
+#include <linux/cleanup.h>
 #include <linux/export.h>
 #include <linux/interrupt.h>
 #include <linux/workqueue.h>
@@ -80,7 +81,7 @@ static ssize_t ad5446_write_dac_powerdown(struct iio_dev *indio_dev,
        if (ret)
                return ret;
 
-       mutex_lock(&st->lock);
+       guard(mutex)(&st->lock);
        st->pwr_down = powerdown;
 
        if (st->pwr_down) {
@@ -91,9 +92,10 @@ static ssize_t ad5446_write_dac_powerdown(struct iio_dev *indio_dev,
        }
 
        ret = st->chip_info->write(st, val);
-       mutex_unlock(&st->lock);
+       if (ret)
+               return ret;
 
-       return ret ? ret : len;
+       return len;
 }
 
 const struct iio_chan_spec_ext_info ad5446_ext_info_powerdown[] = {
@@ -129,32 +131,37 @@ static int ad5446_read_raw(struct iio_dev *indio_dev,
        return -EINVAL;
 }
 
+static int ad5446_write_dac_raw(struct iio_dev *indio_dev,
+                               const struct iio_chan_spec *chan,
+                               int val)
+{
+       struct ad5446_state *st = iio_priv(indio_dev);
+
+       if (val >= (1 << chan->scan_type.realbits) || val < 0)
+               return -EINVAL;
+
+       val <<= chan->scan_type.shift;
+       guard(mutex)(&st->lock);
+
+       st->cached_val = val;
+       if (st->pwr_down)
+               return 0;
+
+       return st->chip_info->write(st, val);
+}
+
 static int ad5446_write_raw(struct iio_dev *indio_dev,
                               struct iio_chan_spec const *chan,
                               int val,
                               int val2,
                               long mask)
 {
-       struct ad5446_state *st = iio_priv(indio_dev);
-       int ret = 0;
-
        switch (mask) {
        case IIO_CHAN_INFO_RAW:
-               if (val >= (1 << chan->scan_type.realbits) || val < 0)
-                       return -EINVAL;
-
-               val <<= chan->scan_type.shift;
-               mutex_lock(&st->lock);
-               st->cached_val = val;
-               if (!st->pwr_down)
-                       ret = st->chip_info->write(st, val);
-               mutex_unlock(&st->lock);
-               break;
+               return ad5446_write_dac_raw(indio_dev, chan, val);
        default:
-               ret = -EINVAL;
+               return -EINVAL;
        }
-
-       return ret;
 }
 
 static const struct iio_info ad5446_info = {