iio: dac: ad5446: Replace indio_dev->mlock with own device lock

As part of the general cleanup of indio_dev->mlock, this change replaces
it with a local lock on the device's state structure.

Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@analog.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 9884e29..8f8afc8 100644 (file)
--- a/drivers/iio/dac/ad5446.c
+++ b/drivers/iio/dac/ad5446.c
@@ -33,6 +33,7 @@
  * @chip_info:         chip model specific constants, available modes etc
  * @reg:               supply regulator
  * @vref_mv:           actual reference voltage used
+ * @lock               lock to protect the data buffer during write ops
  */
 
 struct ad5446_state {
@@ -43,6 +44,7 @@ struct ad5446_state {
        unsigned                        cached_val;
        unsigned                        pwr_down_mode;
        unsigned                        pwr_down;
+       struct mutex                    lock;
 };
 
 /**
@@ -112,7 +114,7 @@ static ssize_t ad5446_write_dac_powerdown(struct iio_dev *indio_dev,
        if (ret)
                return ret;
 
-       mutex_lock(&indio_dev->mlock);
+       mutex_lock(&st->lock);
        st->pwr_down = powerdown;
 
        if (st->pwr_down) {
@@ -123,7 +125,7 @@ static ssize_t ad5446_write_dac_powerdown(struct iio_dev *indio_dev,
        }
 
        ret = st->chip_info->write(st, val);
-       mutex_unlock(&indio_dev->mlock);
+       mutex_unlock(&st->lock);
 
        return ret ? ret : len;
 }
@@ -197,11 +199,11 @@ static int ad5446_write_raw(struct iio_dev *indio_dev,
                        return -EINVAL;
 
                val <<= chan->scan_type.shift;
-               mutex_lock(&indio_dev->mlock);
+               mutex_lock(&st->lock);
                st->cached_val = val;
                if (!st->pwr_down)
                        ret = st->chip_info->write(st, val);
-               mutex_unlock(&indio_dev->mlock);
+               mutex_unlock(&st->lock);
                break;
        default:
                ret = -EINVAL;
@@ -256,6 +258,8 @@ static int ad5446_probe(struct device *dev, const char *name,
        indio_dev->channels = &st->chip_info->channel;
        indio_dev->num_channels = 1;
 
+       mutex_init(&st->lock);
+
        st->pwr_down_mode = MODE_PWRDWN_1k;
 
        if (st->chip_info->int_vref_mv)