[PATCH] iio: dac: ad5761: Replace indio_dev->mlock with own device lock

[Sergiu Cuciurean <sergiu.cuciurean@xxxxxxxxxx>]

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@xxxxxxxxxx>
---
 drivers/iio/dac/ad5761.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/dac/ad5761.c b/drivers/iio/dac/ad5761.c
index 4fb42b743f0f..67179944e5c5 100644
--- a/drivers/iio/dac/ad5761.c
+++ b/drivers/iio/dac/ad5761.c
@@ -57,11 +57,13 @@ enum ad5761_supported_device_ids {
  * @use_intref:		true when the internal voltage reference is used
  * @vref:		actual voltage reference in mVolts
  * @range:		output range mode used
+ * @lock		lock to protect the data buffer during SPI ops
  * @data:		cache aligned spi buffer
  */
 struct ad5761_state {
 	struct spi_device		*spi;
 	struct regulator		*vref_reg;
+	struct mutex			lock;
 
 	bool use_intref;
 	int vref;
@@ -124,9 +126,9 @@ static int ad5761_spi_write(struct iio_dev *indio_dev, u8 addr, u16 val)
 	struct ad5761_state *st = iio_priv(indio_dev);
 	int ret;
 
-	mutex_lock(&indio_dev->mlock);
+	mutex_lock(&st->lock);
 	ret = _ad5761_spi_write(st, addr, val);
-	mutex_unlock(&indio_dev->mlock);
+	mutex_unlock(&st->lock);
 
 	return ret;
 }
@@ -163,9 +165,9 @@ static int ad5761_spi_read(struct iio_dev *indio_dev, u8 addr, u16 *val)
 	struct ad5761_state *st = iio_priv(indio_dev);
 	int ret;
 
-	mutex_lock(&indio_dev->mlock);
+	mutex_lock(&st->lock);
 	ret = _ad5761_spi_read(st, addr, val);
-	mutex_unlock(&indio_dev->mlock);
+	mutex_unlock(&st->lock);
 
 	return ret;
 }
@@ -368,6 +370,8 @@ static int ad5761_probe(struct spi_device *spi)
 	if (pdata)
 		voltage_range = pdata->voltage_range;
 
+	mutex_init(&st->lock);
+
 	ret = ad5761_spi_set_range(st, voltage_range);
 	if (ret)
 		goto disable_regulator_err;
-- 
2.17.1