[PATCH v1 08/15] iio: adc: ad7768-1: use guard(mutex) to simplify code

[Jonathan Santos <Jonathan.Santos@xxxxxxxxxx>]

Use guard(mutex) from cleanup.h to remove most of the gotos and to make
the code simpler and less likely to fail due to forgetting to unlock
the resources.

Signed-off-by: Jonathan Santos <Jonathan.Santos@xxxxxxxxxx>
---
 drivers/iio/adc/ad7768-1.c | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c
index f73b9aec8b0f..cd1b08053105 100644
--- a/drivers/iio/adc/ad7768-1.c
+++ b/drivers/iio/adc/ad7768-1.c
@@ -5,6 +5,7 @@
  * Copyright 2017 Analog Devices Inc.
  */
 #include <linux/bitfield.h>
+#include <linux/cleanup.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/device.h>
@@ -257,20 +258,12 @@ static int ad7768_reg_access(struct iio_dev *indio_dev,
 			     unsigned int *readval)
 {
 	struct ad7768_state *st = iio_priv(indio_dev);
-	int ret;
 
-	mutex_lock(&st->lock);
-	if (readval) {
-		ret = ad7768_spi_reg_read(st, reg, readval, 1);
-		if (ret < 0)
-			goto err_unlock;
-	} else {
-		ret = ad7768_spi_reg_write(st, reg, writeval);
-	}
-err_unlock:
-	mutex_unlock(&st->lock);
+	guard(mutex)(&st->lock);
+	if (readval)
+		return ad7768_spi_reg_read(st, reg, readval, 1);
 
-	return ret;
+	return ad7768_spi_reg_write(st, reg, writeval);
 }
 
 static int ad7768_set_dig_fil(struct ad7768_state *st,
@@ -484,7 +477,7 @@ static irqreturn_t ad7768_trigger_handler(int irq, void *p)
 	struct ad7768_state *st = iio_priv(indio_dev);
 	int ret;
 
-	mutex_lock(&st->lock);
+	guard(mutex)(&st->lock);
 
 	ret = spi_read(st->spi, &st->data.scan.chan, 3);
 	if (ret < 0)
@@ -495,7 +488,6 @@ static irqreturn_t ad7768_trigger_handler(int irq, void *p)
 
 err_unlock:
 	iio_trigger_notify_done(indio_dev->trig);
-	mutex_unlock(&st->lock);
 
 	return IRQ_HANDLED;
 }
-- 
2.34.1