The IIO subsystem is redefining iio_dev->mlock to be used by
the IIO core only for protecting device operating mode changes.
ie. Changes between INDIO_DIRECT_MODE, INDIO_BUFFER_* modes.
In this driver, mlock was being used to protect hardware state
changes. Replace it with a driver private lock.
Also, as there are state changes in the ad7192_ write_raw function, a lock
is added to prevent the concurrent state changes.
Signed-off-by: Aastha Gupta <aastha.gupta4104@xxxxxxxxx>
---
changes in v4:
- added comment for mutex
- improved commit message
drivers/staging/iio/adc/ad7192.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/iio/adc/ad7192.c b/drivers/staging/iio/adc/ad7192.c
index d11c6de..c1343ec 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;
@@ -510,6 +511,7 @@ static int ad7192_write_raw(struct iio_dev *indio_dev,
switch (mask) {
case IIO_CHAN_INFO_SCALE:
ret = -EINVAL;
+ mutex_lock(&st->lock);
for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
if (val2 == st->scale_avail[i][1]) {
ret = 0;
@@ -523,6 +525,7 @@ static int ad7192_write_raw(struct iio_dev *indio_dev,
ad7192_calibrate_all(st);
break;
}
+ mutex_unlock(&st->lock);
break;
case IIO_CHAN_INFO_SAMP_FREQ:
if (!val) {
@@ -634,6 +637,8 @@ static int ad7192_probe(struct spi_device *spi)
st = iio_priv(indio_dev);
+ mutex_init(&st->lock);
+
st->avdd = devm_regulator_get(&spi->dev, "avdd");
if (IS_ERR(st->avdd))
return PTR_ERR(st->avdd);
--
2.7.4
--
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