[PATCH v2] leds: lm3642: use guard to simplify locking

From: Richard Lyu

Date: Thu Mar 19 2026 - 23:55:48 EST


The mutex_lock()/mutex_unlock() pattern requires explicitly pairing
lock and unlock calls. Use guard(mutex) instead so the lock is
automatically released when the scope exits.

Convert to guard(mutex) in lm3642_torch_brightness_set(),
lm3642_strobe_brightness_set(), and lm3642_indicator_brightness_set().
Add #include <linux/cleanup.h> to support scoped guards.

Signed-off-by: Richard Lyu <richard.lyu@xxxxxxxx>
---
v2:
- Sort includes alphabetically as requested by Lee Jones.
- Rebase this patch on top.
- Link: https://lore.kernel.org/all/20260319151539.GO554736@xxxxxxxxxx/
---
drivers/leds/leds-lm3642.c | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/drivers/leds/leds-lm3642.c b/drivers/leds/leds-lm3642.c
index 61629d5d6703..36246267b096 100644
--- a/drivers/leds/leds-lm3642.c
+++ b/drivers/leds/leds-lm3642.c
@@ -3,15 +3,16 @@
* Simple driver for Texas Instruments LM3642 LED Flash driver chip
* Copyright (C) 2012 Texas Instruments
*/
-#include <linux/module.h>
+#include <linux/cleanup.h>
#include <linux/delay.h>
+#include <linux/fs.h>
#include <linux/i2c.h>
#include <linux/leds.h>
-#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/platform_data/leds-lm3642.h>
#include <linux/platform_device.h>
-#include <linux/fs.h>
#include <linux/regmap.h>
-#include <linux/platform_data/leds-lm3642.h>
+#include <linux/slab.h>

#define REG_FILT_TIME (0x0)
#define REG_IVFM_MODE (0x1)
@@ -202,10 +203,9 @@ static int lm3642_torch_brightness_set(struct led_classdev *cdev,
container_of(cdev, struct lm3642_chip_data, cdev_torch);
int ret;

- mutex_lock(&chip->lock);
+ guard(mutex)(&chip->lock);
chip->br_torch = brightness;
ret = lm3642_control(chip, chip->br_torch, MODES_TORCH);
- mutex_unlock(&chip->lock);
return ret;
}

@@ -249,10 +249,9 @@ static int lm3642_strobe_brightness_set(struct led_classdev *cdev,
container_of(cdev, struct lm3642_chip_data, cdev_flash);
int ret;

- mutex_lock(&chip->lock);
+ guard(mutex)(&chip->lock);
chip->br_flash = brightness;
ret = lm3642_control(chip, chip->br_flash, MODES_FLASH);
- mutex_unlock(&chip->lock);
return ret;
}

@@ -264,10 +263,9 @@ static int lm3642_indicator_brightness_set(struct led_classdev *cdev,
container_of(cdev, struct lm3642_chip_data, cdev_indicator);
int ret;

- mutex_lock(&chip->lock);
+ guard(mutex)(&chip->lock);
chip->br_indicator = brightness;
ret = lm3642_control(chip, chip->br_indicator, MODES_INDIC);
- mutex_unlock(&chip->lock);
return ret;
}

--
2.51.0