iio: adc: ad7606: switch mutexes to guard

Switching to guard simplifies the code and avoids to take care to
unlock the mutex in case of premature return.

Signed-off-by: Guillaume Stols <gstols@baylibre.com>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
index 50ccc245e314998660fcf3c47408008a1648ad24..539e4a8621fee2f267e528230e83940a4410e4e0 100644 (file)
--- a/drivers/iio/adc/ad7606.c
+++ b/drivers/iio/adc/ad7606.c
@@ -69,19 +69,17 @@ static int ad7606_reg_access(struct iio_dev *indio_dev,
        struct ad7606_state *st = iio_priv(indio_dev);
        int ret;
 
-       mutex_lock(&st->lock);
+       guard(mutex)(&st->lock);
+
        if (readval) {
                ret = st->bops->reg_read(st, reg);
                if (ret < 0)
-                       goto err_unlock;
+                       return ret;
                *readval = ret;
-               ret = 0;
+               return 0;
        } else {
-               ret = st->bops->reg_write(st, reg, writeval);
+               return st->bops->reg_write(st, reg, writeval);
        }
-err_unlock:
-       mutex_unlock(&st->lock);
-       return ret;
 }
 
 static int ad7606_read_samples(struct ad7606_state *st)
@@ -124,19 +122,19 @@ static irqreturn_t ad7606_trigger_handler(int irq, void *p)
        struct ad7606_state *st = iio_priv(indio_dev);
        int ret;
 
-       mutex_lock(&st->lock);
+       guard(mutex)(&st->lock);
 
        ret = ad7606_read_samples(st);
-       if (ret == 0)
-               iio_push_to_buffers_with_timestamp(indio_dev, st->data,
-                                                  iio_get_time_ns(indio_dev));
+       if (ret)
+               goto error_ret;
 
+       iio_push_to_buffers_with_timestamp(indio_dev, st->data,
+                                          iio_get_time_ns(indio_dev));
+error_ret:
        iio_trigger_notify_done(indio_dev->trig);
        /* The rising edge of the CONVST signal starts a new conversion. */
        gpiod_set_value(st->gpio_convst, 1);
 
-       mutex_unlock(&st->lock);
-
        return IRQ_HANDLED;
 }
 
@@ -257,19 +255,17 @@ static int ad7606_write_raw(struct iio_dev *indio_dev,
        struct ad7606_state *st = iio_priv(indio_dev);
        int i, ret, ch = 0;
 
+       guard(mutex)(&st->lock);
+
        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
-               mutex_lock(&st->lock);
                i = find_closest(val2, st->scale_avail, st->num_scales);
                if (st->sw_mode_en)
                        ch = chan->address;
                ret = st->write_scale(indio_dev, ch, i);
-               if (ret < 0) {
-                       mutex_unlock(&st->lock);
+               if (ret < 0)
                        return ret;
-               }
                st->range[ch] = i;
-               mutex_unlock(&st->lock);
 
                return 0;
        case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
@@ -277,14 +273,9 @@ static int ad7606_write_raw(struct iio_dev *indio_dev,
                        return -EINVAL;
                i = find_closest(val, st->oversampling_avail,
                                 st->num_os_ratios);
-               mutex_lock(&st->lock);
                ret = st->write_os(indio_dev, i);
-               if (ret < 0) {
-                       mutex_unlock(&st->lock);
+               if (ret < 0)
                        return ret;
-               }
-               st->oversampling = st->oversampling_avail[i];
-               mutex_unlock(&st->lock);
 
                return 0;
        default: