[PATCH v4 0/2] iio: accel: convert to guard(mutex)

[PATCH v4 0/2] iio: accel: convert to guard(mutex)

[Rajveer Chaudhari]

This series converts manual mutex_lock/mutex_unlock pairs to
guard(mutex) in two ADXL accelerometer drivers. Each conversion
also simplifies error handling by removing goto labels and
returning directly on error paths.

adxl355 was considered but dropped as guard(mutex) leads to
code duplication due to the STANDBY/MEASUREMENT op_mode pattern,
making it less readable than the original code.

Ref to v3: [PATCH v3 0/3] iio: accel: convert to guard(mutex)

Rajveer Chaudhari (2):
  iio: accel: adxl313: convert to guard(mutex)
  iio: accel: adxl372: convert to guard(mutex)

 drivers/iio/accel/adxl313_core.c | 11 ++++-------
 drivers/iio/accel/adxl372.c      | 13 +++++--------
 2 files changed, 9 insertions(+), 15 deletions(-)

-- 
2.53.0

[PATCH v4 1/2] iio: accel: adxl313: convert to guard(mutex)

[Rajveer Chaudhari]

Replace manual mutex_lock/mutex_unlock pair with guard(mutex) in
adxl313_read_axis(). This ensures the mutex is released on all
return paths and allows returning directly without a goto label.

Signed-off-by: Rajveer Chaudhari <rajveer.chaudhari.linux@gmail.com>
---
v4: Keep ret declaration at top of function.
v3: Return directly from regmap_bulk_read error path.
v2: Split into separate patch per driver.
---
 drivers/iio/accel/adxl313_core.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/iio/accel/adxl313_core.c b/drivers/iio/accel/adxl313_core.c
index 9f5d4d2cb325..084037c89ad3 100644
--- a/drivers/iio/accel/adxl313_core.c
+++ b/drivers/iio/accel/adxl313_core.c
@@ -8,6 +8,7 @@
  */
 
 #include <linux/bitfield.h>
+#include <linux/cleanup.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/overflow.h>
@@ -356,19 +357,15 @@ static int adxl313_read_axis(struct adxl313_data *data,
 {
 	int ret;
 
-	mutex_lock(&data->lock);
+	guard(mutex)(&data->lock);
 
 	ret = regmap_bulk_read(data->regmap,
 			       ADXL313_REG_DATA_AXIS(chan->address),
 			       &data->transf_buf, sizeof(data->transf_buf));
 	if (ret)
-		goto unlock_ret;
-
-	ret = le16_to_cpu(data->transf_buf);
+		return ret;
 
-unlock_ret:
-	mutex_unlock(&data->lock);
-	return ret;
+	return le16_to_cpu(data->transf_buf);
 }
 
 static int adxl313_read_freq_avail(struct iio_dev *indio_dev,
-- 
2.53.0

[PATCH v4 2/2] iio: accel: adxl372: convert to guard(mutex)

[Rajveer Chaudhari]

Replace manual mutex_lock/mutex_unlock pair with guard(mutex) in
adxl372_write_threshold_value(). This ensures the mutex is released
on all return paths and allows returning directly without a goto label.

Signed-off-by: Rajveer Chaudhari <rajveer.chaudhari.linux@gmail.com>
---
v4: Changelog moved below --- as requested by Jonathan Cameron.
v3: Return directly from error path without goto.
v2: Split into separate patch per driver.
---
 drivers/iio/accel/adxl372.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/iio/accel/adxl372.c b/drivers/iio/accel/adxl372.c
index 28a8793a53b6..4bf8656991ea 100644
--- a/drivers/iio/accel/adxl372.c
+++ b/drivers/iio/accel/adxl372.c
@@ -7,6 +7,7 @@
 
 #include <linux/bitfield.h>
 #include <linux/bitops.h>
+#include <linux/cleanup.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/module.h>
@@ -336,18 +337,14 @@ static ssize_t adxl372_write_threshold_value(struct iio_dev *indio_dev, unsigned
 	struct adxl372_state *st = iio_priv(indio_dev);
 	int ret;
 
-	mutex_lock(&st->threshold_m);
+	guard(mutex)(&st->threshold_m);
+
 	ret = regmap_write(st->regmap, addr, ADXL372_THRESH_VAL_H_SEL(threshold));
 	if (ret < 0)
-		goto unlock;
+		return ret;
 
-	ret = regmap_update_bits(st->regmap, addr + 1, GENMASK(7, 5),
+	return regmap_update_bits(st->regmap, addr + 1, GENMASK(7, 5),
 				 ADXL372_THRESH_VAL_L_SEL(threshold) << 5);
-
-unlock:
-	mutex_unlock(&st->threshold_m);
-
-	return ret;
 }
 
 static int adxl372_read_axis(struct adxl372_state *st, u8 addr)
-- 
2.53.0

Re: [PATCH v4 2/2] iio: accel: adxl372: convert to guard(mutex)

[Jonathan Cameron]

On Sat,  7 Mar 2026 17:19:12 +0530
Rajveer Chaudhari <rajveer.chaudhari.linux@gmail.com> wrote:

> Replace manual mutex_lock/mutex_unlock pair with guard(mutex) in
> adxl372_write_threshold_value(). This ensures the mutex is released
> on all return paths and allows returning directly without a goto label.
> 
> Signed-off-by: Rajveer Chaudhari <rajveer.chaudhari.linux@gmail.com>
Series applied. One small tweak mentioned below.

Applied to the testing branch of iio.git where the bots poke at it
briefly before I push it out as togreg which linux-next picks up.

Thanks,

Jonathan

> ---
> v4: Changelog moved below --- as requested by Jonathan Cameron.
> v3: Return directly from error path without goto.
> v2: Split into separate patch per driver.
> ---
>  drivers/iio/accel/adxl372.c | 13 +++++--------
>  1 file changed, 5 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/iio/accel/adxl372.c b/drivers/iio/accel/adxl372.c
> index 28a8793a53b6..4bf8656991ea 100644
> --- a/drivers/iio/accel/adxl372.c
> +++ b/drivers/iio/accel/adxl372.c
> @@ -7,6 +7,7 @@
>  
>  #include <linux/bitfield.h>
>  #include <linux/bitops.h>
> +#include <linux/cleanup.h>
>  #include <linux/interrupt.h>
>  #include <linux/irq.h>
>  #include <linux/module.h>
> @@ -336,18 +337,14 @@ static ssize_t adxl372_write_threshold_value(struct iio_dev *indio_dev, unsigned
>  	struct adxl372_state *st = iio_priv(indio_dev);
>  	int ret;
>  
> -	mutex_lock(&st->threshold_m);
> +	guard(mutex)(&st->threshold_m);
> +
>  	ret = regmap_write(st->regmap, addr, ADXL372_THRESH_VAL_H_SEL(threshold));
>  	if (ret < 0)
> -		goto unlock;
> +		return ret;
>  
> -	ret = regmap_update_bits(st->regmap, addr + 1, GENMASK(7, 5),
> +	return regmap_update_bits(st->regmap, addr + 1, GENMASK(7, 5),
>  				 ADXL372_THRESH_VAL_L_SEL(threshold) << 5);

I'd expect a minor indent update to be needed here.  1 more space.

> -
> -unlock:
> -	mutex_unlock(&st->threshold_m);
> -
> -	return ret;
>  }
>  
>  static int adxl372_read_axis(struct adxl372_state *st, u8 addr)