iio: gyro: adis16080: replace mlock with own lock

The lock is used to protect the buffer during reads. Though the spi
routines have their own locks, it may be the case that the buffer needs to
be protected before it's stored and passed to the IIO read hooks.

indio_dev's mlock was used before.
This change replaces it with the driver's own lock.

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

diff --git a/drivers/iio/gyro/adis16080.c b/drivers/iio/gyro/adis16080.c
index 236220d6de029afd210d0dee3d0c7016921de748..1b84b8e112fe1df59e928a8f8ff40e2fc9bb4ffd 100644 (file)
--- a/drivers/iio/gyro/adis16080.c
+++ b/drivers/iio/gyro/adis16080.c
@@ -38,10 +38,12 @@ struct adis16080_chip_info {
  * @us:                        actual spi_device to write data
  * @info:              chip specific parameters
  * @buf:               transmit or receive buffer
+ * @lock               lock to protect buffer during reads
  **/
 struct adis16080_state {
        struct spi_device               *us;
        const struct adis16080_chip_info *info;
+       struct mutex                    lock;
 
        __be16 buf ____cacheline_aligned;
 };
@@ -82,9 +84,9 @@ static int adis16080_read_raw(struct iio_dev *indio_dev,
 
        switch (mask) {
        case IIO_CHAN_INFO_RAW:
-               mutex_lock(&indio_dev->mlock);
+               mutex_lock(&st->lock);
                ret = adis16080_read_sample(indio_dev, chan->address, val);
-               mutex_unlock(&indio_dev->mlock);
+               mutex_unlock(&st->lock);
                return ret ? ret : IIO_VAL_INT;
        case IIO_CHAN_INFO_SCALE:
                switch (chan->type) {
@@ -196,6 +198,8 @@ static int adis16080_probe(struct spi_device *spi)
        /* this is only used for removal purposes */
        spi_set_drvdata(spi, indio_dev);
 
+       mutex_init(&st->lock);
+
        /* Allocate the comms buffers */
        st->us = spi;
        st->info = &adis16080_chip_info[id->driver_data];