[PATCH] iio: adc: mcp320x: Use guard(mutex) for lock handling

[PATCH] iio: adc: mcp320x: Use guard(mutex) for lock handling

[Eduardo Augusto]

Replace the explicit mutex_lock() and mutex_unlock() calls in
mcp320x_read_raw() with guard(mutex)().

This simplifies the error handling paths by removing the need for
the explicit unlock label while keeping the locking semantics
unchanged.

Signed-off-by: Eduardo Augusto <eduardoaugustoabc@ime.usp.br>
Co-developed-by: Gustavo Pagnotta Faria <gustavo.pagnotta@ime.usp.br>
Signed-off-by: Gustavo Pagnotta Faria <gustavo.pagnotta@ime.usp.br>
Co-developed-by: Christian Barry <christian.barry@ime.usp.br>
Signed-off-by: Christian Barry <christian.barry@ime.usp.br>
---
 drivers/iio/adc/mcp320x.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/iio/adc/mcp320x.c b/drivers/iio/adc/mcp320x.c
index 57cff3772..799756f4c 100644
--- a/drivers/iio/adc/mcp320x.c
+++ b/drivers/iio/adc/mcp320x.c
@@ -44,6 +44,7 @@
 #include <linux/mod_devicetable.h>
 #include <linux/iio/iio.h>
 #include <linux/regulator/consumer.h>
+#include <linux/cleanup.h>
 
 enum {
 	mcp3001,
@@ -198,8 +199,7 @@ static int mcp320x_read_raw(struct iio_dev *indio_dev,
 	struct mcp320x *adc = iio_priv(indio_dev);
 	int ret = -EINVAL;
 	int device_index = 0;
-
-	mutex_lock(&adc->lock);
+	guard(mutex)(&adc->lock);
 
 	device_index = spi_get_device_id(adc->spi)->driver_data;
 
@@ -208,7 +208,7 @@ static int mcp320x_read_raw(struct iio_dev *indio_dev,
 		ret = mcp320x_adc_conversion(adc, channel->address,
 			channel->differential, device_index, val);
 		if (ret < 0)
-			goto out;
+			return ret;
 
 		ret = IIO_VAL_INT;
 		break;
@@ -216,7 +216,7 @@ static int mcp320x_read_raw(struct iio_dev *indio_dev,
 	case IIO_CHAN_INFO_SCALE:
 		ret = regulator_get_voltage(adc->reg);
 		if (ret < 0)
-			goto out;
+			return ret;
 
 		/* convert regulator output voltage to mV */
 		*val = ret / 1000;
@@ -225,9 +225,6 @@ static int mcp320x_read_raw(struct iio_dev *indio_dev,
 		break;
 	}
 
-out:
-	mutex_unlock(&adc->lock);
-
 	return ret;
 }
 
-- 
2.34.1

Re: [PATCH] iio: adc: mcp320x: Use guard(mutex) for lock handling

[Andy Shevchenko]

On Wed, Apr 22, 2026 at 06:11:05PM -0300, Eduardo Augusto wrote:
> Replace the explicit mutex_lock() and mutex_unlock() calls in
> mcp320x_read_raw() with guard(mutex)().
> 
> This simplifies the error handling paths by removing the need for
> the explicit unlock label while keeping the locking semantics
> unchanged.

...

>  #include <linux/mod_devicetable.h>
>  #include <linux/iio/iio.h>
>  #include <linux/regulator/consumer.h>
> +#include <linux/cleanup.h>

Please, start reviewing others' contribution first before making your own.
Also learn from other reviews.

-- 
With Best Regards,
Andy Shevchenko