[PATCH] staging: iio: ad7192: Replace mlock with private driver lock

[sayli karnik <karniksayli1995@gmail.com>]

indio_dev->mlock should be used by the IIO core only for protecting
device operating mode changes. ie. Changes between INDIO_DIRECT_MODE,
INDIO_BUFFER_* modes.
Replace mlock with a lock in the device's global data to protect
hardware state changes.

Signed-off-by: sayli karnik <karniksayli1995@gmail.com>
---
 drivers/staging/iio/adc/ad7192.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/iio/adc/ad7192.c b/drivers/staging/iio/adc/ad7192.c
index 4fc8588..bed48e7 100644
--- a/drivers/staging/iio/adc/ad7192.c
+++ b/drivers/staging/iio/adc/ad7192.c
@@ -162,6 +162,7 @@ struct ad7192_state {
 	u32				scale_avail[8][2];
 	u8				gpocon;
 	u8				devid;
+	struct mutex			lock;	/* protect sensor state */
 
 	struct ad_sigma_delta		sd;
 };
@@ -463,10 +464,10 @@ static int ad7192_read_raw(struct iio_dev *indio_dev,
 	case IIO_CHAN_INFO_SCALE:
 		switch (chan->type) {
 		case IIO_VOLTAGE:
-			mutex_lock(&indio_dev->mlock);
+			mutex_lock(&st->lock);
 			*val = st->scale_avail[AD7192_CONF_GAIN(st->conf)][0];
 			*val2 = st->scale_avail[AD7192_CONF_GAIN(st->conf)][1];
-			mutex_unlock(&indio_dev->mlock);
+			mutex_unlock(&st->lock);
 			return IIO_VAL_INT_PLUS_NANO;
 		case IIO_TEMP:
 			*val = 0;
-- 
2.7.4