iio: st_sensors: Stop abusing mlock to ensure internal coherency

An odr_lock has been introduced to protect local accesses to the odr
internal cache and ensure the cached value always reflected the actual
value. Using the mlock() for this purpose is no longer needed, so let's
drop these extra mutex_lock/unlock() calls.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Cc: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20220207143840.707510-8-miquel.raynal@bootlin.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/accel/st_accel_core.c

@@ -1210,8 +1210,6 @@ read_error:
 static int st_accel_write_raw(struct iio_dev *indio_dev,
 		struct iio_chan_spec const *chan, int val, int val2, long mask)
 {
-	int err;
-
 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE: {
 		int gain;
@@ -1222,10 +1220,8 @@ static int st_accel_write_raw(struct iio_dev *indio_dev,
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		if (val2)
 			return -EINVAL;
-		mutex_lock(&indio_dev->mlock);
-		err = st_sensors_set_odr(indio_dev, val);
-		mutex_unlock(&indio_dev->mlock);
-		return err;
+
+		return st_sensors_set_odr(indio_dev, val);
 	default:
 		return -EINVAL;
 	}

drivers/iio/gyro/st_gyro_core.c

@@ -406,18 +406,14 @@ read_error:
 static int st_gyro_write_raw(struct iio_dev *indio_dev,
 		struct iio_chan_spec const *chan, int val, int val2, long mask)
 {
-	int err;
-
 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE:
 		return st_sensors_set_fullscale_by_gain(indio_dev, val2);
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		if (val2)
 			return -EINVAL;
-		mutex_lock(&indio_dev->mlock);
-		err = st_sensors_set_odr(indio_dev, val);
-		mutex_unlock(&indio_dev->mlock);
-		return err;
+
+		return st_sensors_set_odr(indio_dev, val);
 	default:
 		return -EINVAL;
 	}

drivers/iio/magnetometer/st_magn_core.c

@@ -540,18 +540,14 @@ read_error:
 static int st_magn_write_raw(struct iio_dev *indio_dev,
 		struct iio_chan_spec const *chan, int val, int val2, long mask)
 {
-	int err;
-
 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE:
 		return st_sensors_set_fullscale_by_gain(indio_dev, val2);
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		if (val2)
 			return -EINVAL;
-		mutex_lock(&indio_dev->mlock);
-		err = st_sensors_set_odr(indio_dev, val);
-		mutex_unlock(&indio_dev->mlock);
-		return err;
+
+		return st_sensors_set_odr(indio_dev, val);
 	default:
 		return -EINVAL;
 	}

drivers/iio/pressure/st_pressure_core.c

@@ -560,16 +560,12 @@ static int st_press_write_raw(struct iio_dev *indio_dev,
 			      int val2,
 			      long mask)
 {
-	int err;
-
 	switch (mask) {
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		if (val2)
 			return -EINVAL;
-		mutex_lock(&indio_dev->mlock);
-		err = st_sensors_set_odr(indio_dev, val);
-		mutex_unlock(&indio_dev->mlock);
-		return err;
+
+		return st_sensors_set_odr(indio_dev, val);
 	default:
 		return -EINVAL;
 	}