iio: amplifiers: ad8366: use own lock to guard state

This driver is still using iio_dev's mlock to guard against inconsistent
state. This has been discouraged for some time.

This change switches to using it's own mutex, defined on the state struct.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/amplifiers/ad8366.c b/drivers/iio/amplifiers/ad8366.c
index 82ac15914ff38ea179dcb596e91564cf0a4fc8cc..24ff5475d9f2102e7381984ab944a4b44bbbb4cd 100644 (file)
--- a/drivers/iio/amplifiers/ad8366.c
+++ b/drivers/iio/amplifiers/ad8366.c
@@ -21,6 +21,7 @@
 struct ad8366_state {
        struct spi_device       *spi;
        struct regulator        *reg;
+       struct mutex            lock; /* protect sensor state */
        unsigned char           ch[2];
        /*
         * DMA (thus cache coherency maintenance) requires the
@@ -58,7 +59,7 @@ static int ad8366_read_raw(struct iio_dev *indio_dev,
        int ret;
        unsigned code;
 
-       mutex_lock(&indio_dev->mlock);
+       mutex_lock(&st->lock);
        switch (m) {
        case IIO_CHAN_INFO_HARDWAREGAIN:
                code = st->ch[chan->channel];
@@ -73,7 +74,7 @@ static int ad8366_read_raw(struct iio_dev *indio_dev,
        default:
                ret = -EINVAL;
        }
-       mutex_unlock(&indio_dev->mlock);
+       mutex_unlock(&st->lock);
 
        return ret;
 };
@@ -99,7 +100,7 @@ static int ad8366_write_raw(struct iio_dev *indio_dev,
 
        code = (code - 4500) / 253;
 
-       mutex_lock(&indio_dev->mlock);
+       mutex_lock(&st->lock);
        switch (mask) {
        case IIO_CHAN_INFO_HARDWAREGAIN:
                st->ch[chan->channel] = code;
@@ -108,7 +109,7 @@ static int ad8366_write_raw(struct iio_dev *indio_dev,
        default:
                ret = -EINVAL;
        }
-       mutex_unlock(&indio_dev->mlock);
+       mutex_unlock(&st->lock);
 
        return ret;
 }
@@ -151,6 +152,7 @@ static int ad8366_probe(struct spi_device *spi)
        }
 
        spi_set_drvdata(spi, indio_dev);
+       mutex_init(&st->lock);
        st->spi = spi;
 
        indio_dev->dev.parent = &spi->dev;