Merge "leds: implement sysfs interface locking mechanism" (d0057771) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/leds/led-class.c

+16 −3

Original line number	Diff line number	Diff line
		@@ -40,16 +40,26 @@ 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;

		led_cdev->usr_brightness_req = state;
		__led_set_brightness(led_cdev, state);

		return size;
		ret = size;
		unlock:
		mutex_unlock(&led_cdev->led_access);
		return ret;
		}
		static DEVICE_ATTR_RW(brightness);

		@@ -229,6 +239,7 @@ 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);
		@@ -282,6 +293,8 @@ 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);

drivers/leds/led-core.c

+18 −0

Original line number	Diff line number	Diff line
		@@ -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);

drivers/leds/led-triggers.c

+13 −3

Original line number	Diff line number	Diff line
		@@ -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);

include/linux/leds.h

+32 −0

Original line number	Diff line number	Diff line
		@@ -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>
		@@ -43,6 +44,7 @@ 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 */
		@@ -86,6 +88,9 @@ 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,
		@@ -152,6 +157,33 @@ 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
		*/