staging: iio: ad7192: use iio_device_{claim|release}_direct_mode()

Replace the code that guarantees the device stays in direct mode with
iio_device_{claim|release}_direct_mode() which does same.
Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/staging/iio/adc/ad7192.c

@@ -349,11 +349,9 @@ static ssize_t ad7192_write_frequency(struct device *dev,
 	if (lval == 0)
 		return -EINVAL;
 
-	mutex_lock(&indio_dev->mlock);
-	if (iio_buffer_enabled(indio_dev)) {
-		mutex_unlock(&indio_dev->mlock);
-		return -EBUSY;
-	}
+	ret = iio_device_claim_direct_mode(indio_dev);
+	if (ret)
+		return ret;
 
 	div = st->mclk / (lval * st->f_order * 1024);
 	if (div < 1 || div > 1023) {
@@ -366,7 +364,7 @@ static ssize_t ad7192_write_frequency(struct device *dev,
 	ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
 
 out:
-	mutex_unlock(&indio_dev->mlock);
+	iio_device_release_direct_mode(indio_dev);
 
 	return ret ? ret : len;
 }
@@ -434,11 +432,9 @@ static ssize_t ad7192_set(struct device *dev,
 	if (ret < 0)
 		return ret;
 
-	mutex_lock(&indio_dev->mlock);
-	if (iio_buffer_enabled(indio_dev)) {
-		mutex_unlock(&indio_dev->mlock);
-		return -EBUSY;
-	}
+	ret = iio_device_claim_direct_mode(indio_dev);
+	if (ret)
+		return ret;
 
 	switch ((u32)this_attr->address) {
 	case AD7192_REG_GPOCON:
@@ -461,7 +457,7 @@ static ssize_t ad7192_set(struct device *dev,
 		ret = -EINVAL;
 	}
 
-	mutex_unlock(&indio_dev->mlock);
+	iio_device_release_direct_mode(indio_dev);
 
 	return ret ? ret : len;
 }
@@ -555,11 +551,9 @@ static int ad7192_write_raw(struct iio_dev *indio_dev,
 	int ret, i;
 	unsigned int tmp;
 
-	mutex_lock(&indio_dev->mlock);
-	if (iio_buffer_enabled(indio_dev)) {
-		mutex_unlock(&indio_dev->mlock);
-		return -EBUSY;
-	}
+	ret = iio_device_claim_direct_mode(indio_dev);
+	if (ret)
+		return ret;
 
 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE:
@@ -582,7 +576,7 @@ static int ad7192_write_raw(struct iio_dev *indio_dev,
 		ret = -EINVAL;
 	}
 
-	mutex_unlock(&indio_dev->mlock);
+	iio_device_release_direct_mode(indio_dev);
 
 	return ret;
 }