[PATCH v4 7/9] iio: adc: ad7606: protect register access

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@xxxxxxxxxxxx>

Protect register (and bus) access from concurrent
read / write. Needed in the backend operating mode.

Signed-off-by: Angelo Dureghello <adureghello@xxxxxxxxxxxx>
---
 drivers/iio/adc/ad7606.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
index 7985570ed152..07656fdd602e 100644
--- a/drivers/iio/adc/ad7606.c
+++ b/drivers/iio/adc/ad7606.c
@@ -862,7 +862,12 @@ static int ad7606_write_raw(struct iio_dev *indio_dev,
 		}
 		val = (val * MICRO) + val2;
 		i = find_closest(val, scale_avail_uv, cs->num_scales);
+
+		ret = iio_device_claim_direct_mode(indio_dev);
+		if (ret < 0)
+			return ret;
 		ret = st->write_scale(indio_dev, ch, i + cs->reg_offset);
+		iio_device_release_direct_mode(indio_dev);
 		if (ret < 0)
 			return ret;
 		cs->range = i;
@@ -873,7 +878,12 @@ static int ad7606_write_raw(struct iio_dev *indio_dev,
 			return -EINVAL;
 		i = find_closest(val, st->oversampling_avail,
 				 st->num_os_ratios);
+
+		ret = iio_device_claim_direct_mode(indio_dev);
+		if (ret < 0)
+			return ret;
 		ret = st->write_os(indio_dev, i);
+		iio_device_release_direct_mode(indio_dev);
 		if (ret < 0)
 			return ret;
 		st->oversampling = st->oversampling_avail[i];

-- 
2.47.0