diff options
| -rw-r--r-- | drivers/leds/led-class.c | 19 | ||||
| -rw-r--r-- | drivers/leds/led-core.c | 18 | ||||
| -rw-r--r-- | drivers/leds/led-triggers.c | 16 | ||||
| -rw-r--r-- | include/linux/leds.h | 32 |
4 files changed, 79 insertions, 6 deletions
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index 7440c58b8e6f..65722deb8d28 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -40,17 +40,27 @@ static ssize_t brightness_store(struct device *dev, { struct led_classdev *led_cdev = dev_get_drvdata(dev); unsigned long state; - ssize_t ret = -EINVAL; + ssize_t ret; + + mutex_lock(&led_cdev->led_access); + + if (led_sysfs_is_disabled(led_cdev)) { + ret = -EBUSY; + goto unlock; + } ret = kstrtoul(buf, 10, &state); if (ret) - return ret; + goto unlock; if (state == LED_OFF) led_trigger_remove(led_cdev); __led_set_brightness(led_cdev, state); - return size; + ret = size; +unlock: + mutex_unlock(&led_cdev->led_access); + return ret; } static DEVICE_ATTR_RW(brightness); @@ -214,6 +224,7 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev) #ifdef CONFIG_LEDS_TRIGGERS init_rwsem(&led_cdev->trigger_lock); #endif + mutex_init(&led_cdev->led_access); /* add to the list of leds */ down_write(&leds_list_lock); list_add_tail(&led_cdev->node, &leds_list); @@ -267,6 +278,8 @@ void led_classdev_unregister(struct led_classdev *led_cdev) down_write(&leds_list_lock); list_del(&led_cdev->node); up_write(&leds_list_lock); + + mutex_destroy(&led_cdev->led_access); } EXPORT_SYMBOL_GPL(led_classdev_unregister); diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c index aaa8eba9099f..be6d9fa5e971 100644 --- a/drivers/leds/led-core.c +++ b/drivers/leds/led-core.c @@ -143,3 +143,21 @@ int led_update_brightness(struct led_classdev *led_cdev) return ret; } EXPORT_SYMBOL(led_update_brightness); + +/* Caller must ensure led_cdev->led_access held */ +void led_sysfs_disable(struct led_classdev *led_cdev) +{ + lockdep_assert_held(&led_cdev->led_access); + + led_cdev->flags |= LED_SYSFS_DISABLE; +} +EXPORT_SYMBOL_GPL(led_sysfs_disable); + +/* Caller must ensure led_cdev->led_access held */ +void led_sysfs_enable(struct led_classdev *led_cdev) +{ + lockdep_assert_held(&led_cdev->led_access); + + led_cdev->flags &= ~LED_SYSFS_DISABLE; +} +EXPORT_SYMBOL_GPL(led_sysfs_enable); diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c index c3734f10fdd5..e8b1120f486d 100644 --- a/drivers/leds/led-triggers.c +++ b/drivers/leds/led-triggers.c @@ -37,6 +37,14 @@ ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr, char trigger_name[TRIG_NAME_MAX]; struct led_trigger *trig; size_t len; + int ret = count; + + mutex_lock(&led_cdev->led_access); + + if (led_sysfs_is_disabled(led_cdev)) { + ret = -EBUSY; + goto unlock; + } trigger_name[sizeof(trigger_name) - 1] = '\0'; strncpy(trigger_name, buf, sizeof(trigger_name) - 1); @@ -47,7 +55,7 @@ ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr, if (!strcmp(trigger_name, "none")) { led_trigger_remove(led_cdev); - return count; + goto unlock; } down_read(&triggers_list_lock); @@ -58,12 +66,14 @@ ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr, up_write(&led_cdev->trigger_lock); up_read(&triggers_list_lock); - return count; + goto unlock; } } up_read(&triggers_list_lock); - return -EINVAL; +unlock: + mutex_unlock(&led_cdev->led_access); + return ret; } EXPORT_SYMBOL_GPL(led_trigger_store); diff --git a/include/linux/leds.h b/include/linux/leds.h index a57611d0c94e..737f9b1051f2 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -13,6 +13,7 @@ #define __LINUX_LEDS_H_INCLUDED #include <linux/list.h> +#include <linux/mutex.h> #include <linux/rwsem.h> #include <linux/spinlock.h> #include <linux/timer.h> @@ -42,6 +43,7 @@ struct led_classdev { #define LED_BLINK_ONESHOT (1 << 17) #define LED_BLINK_ONESHOT_STOP (1 << 18) #define LED_BLINK_INVERT (1 << 19) +#define LED_SYSFS_DISABLE (1 << 20) /* Set LED brightness level */ /* Must not sleep, use a workqueue if needed */ @@ -85,6 +87,9 @@ struct led_classdev { /* true if activated - deactivate routine uses it to do cleanup */ bool activated; #endif + + /* Ensures consistent access to the LED Flash Class device */ + struct mutex led_access; }; extern int led_classdev_register(struct device *parent, @@ -151,6 +156,33 @@ extern void led_set_brightness(struct led_classdev *led_cdev, */ extern int led_update_brightness(struct led_classdev *led_cdev); +/** + * led_sysfs_disable - disable LED sysfs interface + * @led_cdev: the LED to set + * + * Disable the led_cdev's sysfs interface. + */ +extern void led_sysfs_disable(struct led_classdev *led_cdev); + +/** + * led_sysfs_enable - enable LED sysfs interface + * @led_cdev: the LED to set + * + * Enable the led_cdev's sysfs interface. + */ +extern void led_sysfs_enable(struct led_classdev *led_cdev); + +/** + * led_sysfs_is_disabled - check if LED sysfs interface is disabled + * @led_cdev: the LED to query + * + * Returns: true if the led_cdev's sysfs interface is disabled. + */ +static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev) +{ + return led_cdev->flags & LED_SYSFS_DISABLE; +} + /* * LED Triggers */ |