[PATCH 3/3] iio: addac: ad74413r: simplify with cleanup.h

[Nuno Sa via B4 Relay <devnull+nuno.sa.analog.com@kernel.org>]

From: Nuno Sa <nuno.sa@analog.com>

Make use of mutex guard() and IIO iio_device_claim_direct_scoped() to
simplify code and error handling.

While at it, use devm_mutex_init() to initialize the mutex.

Signed-off-by: Nuno Sa <nuno.sa@analog.com>
---
 drivers/iio/addac/ad74413r.c | 37 +++++++++++++++----------------------
 1 file changed, 15 insertions(+), 22 deletions(-)

diff --git a/drivers/iio/addac/ad74413r.c b/drivers/iio/addac/ad74413r.c
index cfe26a394465..daea2bde7acf 100644
--- a/drivers/iio/addac/ad74413r.c
+++ b/drivers/iio/addac/ad74413r.c
@@ -6,6 +6,7 @@
 
 #include <linux/unaligned.h>
 #include <linux/bitfield.h>
+#include <linux/cleanup.h>
 #include <linux/crc8.h>
 #include <linux/device.h>
 #include <linux/err.h>
@@ -864,19 +865,12 @@ static int ad74413r_get_single_adc_result(struct iio_dev *indio_dev,
 					  unsigned int channel, int *val)
 {
 	struct ad74413r_state *st = iio_priv(indio_dev);
-	int ret;
 
-	ret = iio_device_claim_direct_mode(indio_dev);
-	if (ret)
-		return ret;
-
-	mutex_lock(&st->lock);
-	ret = _ad74413r_get_single_adc_result(st, channel, val);
-	mutex_unlock(&st->lock);
-
-	iio_device_release_direct_mode(indio_dev);
-
-	return ret;
+	iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
+		guard(mutex)(&st->lock);
+		return _ad74413r_get_single_adc_result(st, channel, val);
+	}
+	unreachable();
 }
 
 static void ad74413r_adc_to_resistance_result(int adc_result, int *val)
@@ -898,7 +892,7 @@ static int ad74413r_update_scan_mode(struct iio_dev *indio_dev,
 	unsigned int channel;
 	int ret = -EINVAL;
 
-	mutex_lock(&st->lock);
+	guard(mutex)(&st->lock);
 
 	spi_message_init(&st->adc_samples_msg);
 	st->adc_active_channels = 0;
@@ -906,11 +900,11 @@ static int ad74413r_update_scan_mode(struct iio_dev *indio_dev,
 	for_each_clear_bit(channel, active_scan_mask, AD74413R_CHANNEL_MAX) {
 		ret = ad74413r_set_adc_channel_enable(st, channel, false);
 		if (ret)
-			goto out;
+			return ret;
 	}
 
 	if (*active_scan_mask == 0)
-		goto out;
+		return ret;
 
 	/*
 	 * The read select register is used to select which register's value
@@ -928,7 +922,7 @@ static int ad74413r_update_scan_mode(struct iio_dev *indio_dev,
 	for_each_set_bit(channel, active_scan_mask, AD74413R_CHANNEL_MAX) {
 		ret = ad74413r_set_adc_channel_enable(st, channel, true);
 		if (ret)
-			goto out;
+			return ret;
 
 		st->adc_active_channels++;
 
@@ -959,11 +953,7 @@ static int ad74413r_update_scan_mode(struct iio_dev *indio_dev,
 	xfer->cs_change = 0;
 
 	spi_message_add_tail(xfer, &st->adc_samples_msg);
-
-out:
-	mutex_unlock(&st->lock);
-
-	return ret;
+	return 0;
 }
 
 static int ad74413r_buffer_postenable(struct iio_dev *indio_dev)
@@ -1368,7 +1358,10 @@ static int ad74413r_probe(struct spi_device *spi)
 	if (!st->chip_info)
 		return -EINVAL;
 
-	mutex_init(&st->lock);
+	ret = devm_mutex_init(st->dev, &st->lock);
+	if (ret)
+		return ret;
+
 	init_completion(&st->adc_data_completion);
 
 	st->regmap = devm_regmap_init(st->dev, NULL, st,

-- 
2.46.1