[PATCH 1/2] iio: light: iqs621-als: use lock guards
Pedro Barletta Gennari
pedro.pbg em usp.br
Ter Abr 28 20:35:50 -03 2026
Use guard(mutex)() for handling mutex lock instead of
manually locking and unlocking the mutex. This prevents forgotten
locks due to early exits and removes the need of gotos.
Signed-off-by: Pedro Barletta Gennari <pedro.pbg em usp.br>
---
drivers/iio/light/iqs621-als.c | 93 ++++++++++++----------------------
1 file changed, 31 insertions(+), 62 deletions(-)
diff --git a/drivers/iio/light/iqs621-als.c b/drivers/iio/light/iqs621-als.c
index b9f230210f07..25a655b328fc 100644
--- a/drivers/iio/light/iqs621-als.c
+++ b/drivers/iio/light/iqs621-als.c
@@ -5,6 +5,7 @@
* Copyright (C) 2019 Jeff LaBundy <jeff em labundy.com>
*/
+#include <linux/cleanup.h>
#include <linux/device.h>
#include <linux/iio/events.h>
#include <linux/iio/iio.h>
@@ -107,26 +108,20 @@ static int iqs621_als_notifier(struct notifier_block *notifier,
indio_dev = iqs621_als->indio_dev;
timestamp = iio_get_time_ns(indio_dev);
- mutex_lock(&iqs621_als->lock);
+ guard(mutex)(&iqs621_als->lock);
if (event_flags & BIT(IQS62X_EVENT_SYS_RESET)) {
ret = iqs621_als_init(iqs621_als);
if (ret) {
dev_err(indio_dev->dev.parent,
"Failed to re-initialize device: %d\n", ret);
- ret = NOTIFY_BAD;
- } else {
- ret = NOTIFY_OK;
+ return NOTIFY_BAD;
}
-
- goto err_mutex;
+ return NOTIFY_OK;
}
- if (!iqs621_als->light_en && !iqs621_als->range_en &&
- !iqs621_als->prox_en) {
- ret = NOTIFY_DONE;
- goto err_mutex;
- }
+ if (!iqs621_als->light_en && !iqs621_als->range_en && !iqs621_als->prox_en)
+ return NOTIFY_DONE;
/* IQS621 only */
light_new = event_data->als_flags & IQS621_ALS_FLAGS_LIGHT;
@@ -181,12 +176,7 @@ static int iqs621_als_notifier(struct notifier_block *notifier,
iqs621_als->als_flags = event_data->als_flags;
iqs621_als->ir_flags = event_data->ir_flags;
- ret = NOTIFY_OK;
-
-err_mutex:
- mutex_unlock(&iqs621_als->lock);
-
- return ret;
+ return NOTIFY_OK;
}
static void iqs621_als_notifier_unregister(void *context)
@@ -241,30 +231,22 @@ static int iqs621_als_read_event_config(struct iio_dev *indio_dev,
enum iio_event_direction dir)
{
struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
- int ret;
- mutex_lock(&iqs621_als->lock);
+ guard(mutex)(&iqs621_als->lock);
switch (chan->type) {
case IIO_LIGHT:
- ret = iqs621_als->light_en;
- break;
+ return iqs621_als->light_en;
case IIO_INTENSITY:
- ret = iqs621_als->range_en;
- break;
+ return iqs621_als->range_en;
case IIO_PROXIMITY:
- ret = iqs621_als->prox_en;
- break;
+ return iqs621_als->prox_en;
default:
- ret = -EINVAL;
+ return -EINVAL;
}
-
- mutex_unlock(&iqs621_als->lock);
-
- return ret;
}
static int iqs621_als_write_event_config(struct iio_dev *indio_dev,
@@ -278,11 +260,11 @@ static int iqs621_als_write_event_config(struct iio_dev *indio_dev,
unsigned int val;
int ret;
- mutex_lock(&iqs621_als->lock);
+ guard(mutex)(&iqs621_als->lock);
ret = regmap_read(iqs62x->regmap, iqs62x->dev_desc->als_flags, &val);
if (ret)
- goto err_mutex;
+ return ret;
iqs621_als->als_flags = val;
switch (chan->type) {
@@ -293,7 +275,7 @@ static int iqs621_als_write_event_config(struct iio_dev *indio_dev,
0xFF);
if (!ret)
iqs621_als->light_en = state;
- break;
+ return ret;
case IIO_INTENSITY:
ret = regmap_update_bits(iqs62x->regmap, IQS620_GLBL_EVENT_MASK,
@@ -302,12 +284,12 @@ static int iqs621_als_write_event_config(struct iio_dev *indio_dev,
0xFF);
if (!ret)
iqs621_als->range_en = state;
- break;
+ return ret;
case IIO_PROXIMITY:
ret = regmap_read(iqs62x->regmap, IQS622_IR_FLAGS, &val);
if (ret)
- goto err_mutex;
+ return ret;
iqs621_als->ir_flags = val;
ret = regmap_update_bits(iqs62x->regmap, IQS620_GLBL_EVENT_MASK,
@@ -315,16 +297,11 @@ static int iqs621_als_write_event_config(struct iio_dev *indio_dev,
state ? 0 : 0xFF);
if (!ret)
iqs621_als->prox_en = state;
- break;
+ return ret;
default:
- ret = -EINVAL;
+ return -EINVAL;
}
-
-err_mutex:
- mutex_unlock(&iqs621_als->lock);
-
- return ret;
}
static int iqs621_als_read_event_value(struct iio_dev *indio_dev,
@@ -335,33 +312,28 @@ static int iqs621_als_read_event_value(struct iio_dev *indio_dev,
int *val, int *val2)
{
struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
- int ret = IIO_VAL_INT;
- mutex_lock(&iqs621_als->lock);
+ guard(mutex)(&iqs621_als->lock);
switch (dir) {
case IIO_EV_DIR_RISING:
*val = iqs621_als->thresh_light * 16;
- break;
+ return IIO_VAL_INT;
case IIO_EV_DIR_FALLING:
*val = iqs621_als->thresh_dark * 4;
- break;
+ return IIO_VAL_INT;
case IIO_EV_DIR_EITHER:
if (iqs621_als->ir_flags_mask == IQS622_IR_FLAGS_TOUCH)
*val = iqs621_als->thresh_prox * 4;
else
*val = iqs621_als->thresh_prox;
- break;
+ return IIO_VAL_INT;
default:
- ret = -EINVAL;
+ return -EINVAL;
}
-
- mutex_unlock(&iqs621_als->lock);
-
- return ret;
}
static int iqs621_als_write_event_value(struct iio_dev *indio_dev,
@@ -375,9 +347,9 @@ static int iqs621_als_write_event_value(struct iio_dev *indio_dev,
struct iqs62x_core *iqs62x = iqs621_als->iqs62x;
unsigned int thresh_reg, thresh_val;
u8 ir_flags_mask, *thresh_cache;
- int ret = -EINVAL;
+ int ret;
- mutex_lock(&iqs621_als->lock);
+ guard(mutex)(&iqs621_als->lock);
switch (dir) {
case IIO_EV_DIR_RISING:
@@ -426,30 +398,27 @@ static int iqs621_als_write_event_value(struct iio_dev *indio_dev,
break;
default:
- goto err_mutex;
+ return -EINVAL;
}
thresh_cache = &iqs621_als->thresh_prox;
break;
default:
- goto err_mutex;
+ return -EINVAL;
}
if (thresh_val > 0xFF)
- goto err_mutex;
+ return -EINVAL;
ret = regmap_write(iqs62x->regmap, thresh_reg, thresh_val);
if (ret)
- goto err_mutex;
+ return ret;
*thresh_cache = thresh_val;
iqs621_als->ir_flags_mask = ir_flags_mask;
-err_mutex:
- mutex_unlock(&iqs621_als->lock);
-
- return ret;
+ return 0;
}
static const struct iio_info iqs621_als_info = {
--
2.51.0
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