drivers/leds/led-core.c - kernel/msm-4.9 - Gitiles

 /*
  * LED Class Core
  *
  * Copyright 2005-2006 Openedhand Ltd.
  *
  * Author: Richard Purdie <rpurdie@openedhand.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  */

 #include <linux/kernel.h>
 #include <linux/leds.h>
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/rwsem.h>
 #include "leds.h"

 DECLARE_RWSEM(leds_list_lock);
 EXPORT_SYMBOL_GPL(leds_list_lock);

 LIST_HEAD(leds_list);
 EXPORT_SYMBOL_GPL(leds_list);

 static void led_timer_function(unsigned long data)
 {
 	struct led_classdev *led_cdev = (void *)data;
 	unsigned long brightness;
 	unsigned long delay;

 	if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
 		led_set_brightness_nosleep(led_cdev, LED_OFF);
 		return;
 	}

 	if (led_cdev->flags & LED_BLINK_ONESHOT_STOP) {
 		led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
 		return;
 	}

 	brightness = led_get_brightness(led_cdev);
 	if (!brightness) {
 		/* Time to switch the LED on. */
 		brightness = led_cdev->blink_brightness;
 		delay = led_cdev->blink_delay_on;
 	} else {
 		/* Store the current brightness value to be able
 		 * to restore it when the delay_off period is over.
 		 * Do it only if there is no pending blink brightness
 		 * change, to avoid overwriting the new value.
 		 */
 		if (!(led_cdev->flags & LED_BLINK_BRIGHTNESS_CHANGE))
 			led_cdev->blink_brightness = brightness;
 		else
 			led_cdev->flags &= ~LED_BLINK_BRIGHTNESS_CHANGE;
 		brightness = LED_OFF;
 		delay = led_cdev->blink_delay_off;
 	}

 	led_set_brightness_nosleep(led_cdev, brightness);

 	/* Return in next iteration if led is in one-shot mode and we are in
 	 * the final blink state so that the led is toggled each delay_on +
 	 * delay_off milliseconds in worst case.
 	 */
 	if (led_cdev->flags & LED_BLINK_ONESHOT) {
 		if (led_cdev->flags & LED_BLINK_INVERT) {
 			if (brightness)
 				led_cdev->flags |= LED_BLINK_ONESHOT_STOP;
 		} else {
 			if (!brightness)
 				led_cdev->flags |= LED_BLINK_ONESHOT_STOP;
 		}
 	}

 	mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
 }

 static void set_brightness_delayed(struct work_struct *ws)
 {
 	struct led_classdev *led_cdev =
 		container_of(ws, struct led_classdev, set_brightness_work);
 	int ret = 0;

 	if (led_cdev->flags & LED_BLINK_DISABLE) {
 		led_cdev->delayed_set_value = LED_OFF;
 		led_stop_software_blink(led_cdev);
 		led_cdev->flags &= ~LED_BLINK_DISABLE;
 	}

 	if (led_cdev->brightness_set)
 		led_cdev->brightness_set(led_cdev, led_cdev->delayed_set_value);
 	else if (led_cdev->brightness_set_blocking)
 		ret = led_cdev->brightness_set_blocking(led_cdev,
 						led_cdev->delayed_set_value);
 	else
 		ret = -ENOTSUPP;
 	if (ret < 0 &&
 	    /* LED HW might have been unplugged, therefore don't warn */
 	    !(ret == -ENODEV && (led_cdev->flags & LED_UNREGISTERING) &&
 	    (led_cdev->flags & LED_HW_PLUGGABLE)))
 		dev_err(led_cdev->dev,
 			"Setting an LED's brightness failed (%d)\n", ret);
 }

 static void led_set_software_blink(struct led_classdev *led_cdev,
 				   unsigned long delay_on,
 				   unsigned long delay_off)
 {
 	int current_brightness;

 	current_brightness = led_get_brightness(led_cdev);
 	if (current_brightness)
 		led_cdev->blink_brightness = current_brightness;
 	if (!led_cdev->blink_brightness)
 		led_cdev->blink_brightness = led_cdev->max_brightness;

 	led_cdev->blink_delay_on = delay_on;
 	led_cdev->blink_delay_off = delay_off;

 	/* never on - just set to off */
 	if (!delay_on) {
 		led_set_brightness_nosleep(led_cdev, LED_OFF);
 		return;
 	}

 	/* never off - just set to brightness */
 	if (!delay_off) {
 		led_set_brightness_nosleep(led_cdev,
 					   led_cdev->blink_brightness);
 		return;
 	}

 	mod_timer(&led_cdev->blink_timer, jiffies + 1);
 }


 static void led_blink_setup(struct led_classdev *led_cdev,
 		     unsigned long *delay_on,
 		     unsigned long *delay_off)
 {
 	if (!(led_cdev->flags & LED_BLINK_ONESHOT) &&
 	    led_cdev->blink_set &&
 	    !led_cdev->blink_set(led_cdev, delay_on, delay_off))
 		return;

 	/* blink with 1 Hz as default if nothing specified */
 	if (!*delay_on && !*delay_off)
 		*delay_on = *delay_off = 500;

 	led_set_software_blink(led_cdev, *delay_on, *delay_off);
 }

 void led_init_core(struct led_classdev *led_cdev)
 {
 	INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);

 	setup_timer(&led_cdev->blink_timer, led_timer_function,
 		    (unsigned long)led_cdev);
 }
 EXPORT_SYMBOL_GPL(led_init_core);

 void led_blink_set(struct led_classdev *led_cdev,
 		   unsigned long *delay_on,
 		   unsigned long *delay_off)
 {
 	del_timer_sync(&led_cdev->blink_timer);

 	led_cdev->flags &= ~LED_BLINK_ONESHOT;
 	led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;

 	led_blink_setup(led_cdev, delay_on, delay_off);
 }
 EXPORT_SYMBOL_GPL(led_blink_set);

 void led_blink_set_oneshot(struct led_classdev *led_cdev,
 			   unsigned long *delay_on,
 			   unsigned long *delay_off,
 			   int invert)
 {
 	if ((led_cdev->flags & LED_BLINK_ONESHOT) &&
 	     timer_pending(&led_cdev->blink_timer))
 		return;

 	led_cdev->flags |= LED_BLINK_ONESHOT;
 	led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;

 	if (invert)
 		led_cdev->flags |= LED_BLINK_INVERT;
 	else
 		led_cdev->flags &= ~LED_BLINK_INVERT;

 	led_blink_setup(led_cdev, delay_on, delay_off);
 }
 EXPORT_SYMBOL_GPL(led_blink_set_oneshot);

 void led_stop_software_blink(struct led_classdev *led_cdev)
 {
 	del_timer_sync(&led_cdev->blink_timer);
 	led_cdev->blink_delay_on = 0;
 	led_cdev->blink_delay_off = 0;
 }
 EXPORT_SYMBOL_GPL(led_stop_software_blink);

 void led_set_brightness(struct led_classdev *led_cdev,
 			enum led_brightness brightness)
 {
 	/*
 	 * In case blinking is on delay brightness setting
 	 * until the next timer tick.
 	 */
 	if (led_cdev->blink_delay_on || led_cdev->blink_delay_off) {
 		/*
 		 * If we need to disable soft blinking delegate this to the
 		 * work queue task to avoid problems in case we are called
 		 * from hard irq context.
 		 */
 		if (brightness == LED_OFF) {
 			led_cdev->flags |= LED_BLINK_DISABLE;
 			schedule_work(&led_cdev->set_brightness_work);
 		} else {
 			led_cdev->flags |= LED_BLINK_BRIGHTNESS_CHANGE;
 			led_cdev->blink_brightness = brightness;
 		}
 		return;
 	}

 	led_set_brightness_nosleep(led_cdev, brightness);
 }
 EXPORT_SYMBOL_GPL(led_set_brightness);

 void led_set_brightness_nopm(struct led_classdev *led_cdev,
 			      enum led_brightness value)
 {
 	/* Use brightness_set op if available, it is guaranteed not to sleep */
 	if (led_cdev->brightness_set) {
 		led_cdev->brightness_set(led_cdev, value);
 		return;
 	}

 	/* If brightness setting can sleep, delegate it to a work queue task */
 	led_cdev->delayed_set_value = value;
 	schedule_work(&led_cdev->set_brightness_work);
 }
 EXPORT_SYMBOL_GPL(led_set_brightness_nopm);

 void led_set_brightness_nosleep(struct led_classdev *led_cdev,
 				enum led_brightness value)
 {
 	led_cdev->brightness = min(value, led_cdev->max_brightness);

 	if (led_cdev->flags & LED_SUSPENDED)
 		return;

 	led_set_brightness_nopm(led_cdev, led_cdev->brightness);
 }
 EXPORT_SYMBOL_GPL(led_set_brightness_nosleep);

 int led_set_brightness_sync(struct led_classdev *led_cdev,
 			    enum led_brightness value)
 {
 	if (led_cdev->blink_delay_on || led_cdev->blink_delay_off)
 		return -EBUSY;

 	led_cdev->brightness = min(value, led_cdev->max_brightness);

 	if (led_cdev->flags & LED_SUSPENDED)
 		return 0;

 	if (led_cdev->brightness_set_blocking)
 		return led_cdev->brightness_set_blocking(led_cdev,
 							 led_cdev->brightness);
 	return -ENOTSUPP;
 }
 EXPORT_SYMBOL_GPL(led_set_brightness_sync);

 int led_update_brightness(struct led_classdev *led_cdev)
 {
 	int ret = 0;

 	if (led_cdev->brightness_get) {
 		ret = led_cdev->brightness_get(led_cdev);
 		if (ret >= 0) {
 			led_cdev->brightness = ret;
 			return 0;
 		}
 	}

 	return ret;
 }
 EXPORT_SYMBOL_GPL(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);
	/*
	* LED Class Core
	*
	* Copyright 2005-2006 Openedhand Ltd.
	*
	* Author: Richard Purdie <rpurdie@openedhand.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	*/

	#include <linux/kernel.h>
	#include <linux/leds.h>
	#include <linux/list.h>
	#include <linux/module.h>
	#include <linux/mutex.h>
	#include <linux/rwsem.h>
	#include "leds.h"

	DECLARE_RWSEM(leds_list_lock);
	EXPORT_SYMBOL_GPL(leds_list_lock);

	LIST_HEAD(leds_list);
	EXPORT_SYMBOL_GPL(leds_list);

	static void led_timer_function(unsigned long data)
	{
	struct led_classdev led_cdev = (void )data;
	unsigned long brightness;
	unsigned long delay;

	if (!led_cdev->blink_delay_on \|\| !led_cdev->blink_delay_off) {
	led_set_brightness_nosleep(led_cdev, LED_OFF);
	return;
	}

	if (led_cdev->flags & LED_BLINK_ONESHOT_STOP) {
	led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
	return;
	}

	brightness = led_get_brightness(led_cdev);
	if (!brightness) {
	/* Time to switch the LED on. */
	brightness = led_cdev->blink_brightness;
	delay = led_cdev->blink_delay_on;
	} else {
	/* Store the current brightness value to be able
	* to restore it when the delay_off period is over.
	* Do it only if there is no pending blink brightness
	* change, to avoid overwriting the new value.
	*/
	if (!(led_cdev->flags & LED_BLINK_BRIGHTNESS_CHANGE))
	led_cdev->blink_brightness = brightness;
	else
	led_cdev->flags &= ~LED_BLINK_BRIGHTNESS_CHANGE;
	brightness = LED_OFF;
	delay = led_cdev->blink_delay_off;
	}

	led_set_brightness_nosleep(led_cdev, brightness);

	/* Return in next iteration if led is in one-shot mode and we are in
	* the final blink state so that the led is toggled each delay_on +
	* delay_off milliseconds in worst case.
	*/
	if (led_cdev->flags & LED_BLINK_ONESHOT) {
	if (led_cdev->flags & LED_BLINK_INVERT) {
	if (brightness)
	led_cdev->flags \|= LED_BLINK_ONESHOT_STOP;
	} else {
	if (!brightness)
	led_cdev->flags \|= LED_BLINK_ONESHOT_STOP;
	}
	}

	mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
	}

	static void set_brightness_delayed(struct work_struct *ws)
	{
	struct led_classdev *led_cdev =
	container_of(ws, struct led_classdev, set_brightness_work);
	int ret = 0;

	if (led_cdev->flags & LED_BLINK_DISABLE) {
	led_cdev->delayed_set_value = LED_OFF;
	led_stop_software_blink(led_cdev);
	led_cdev->flags &= ~LED_BLINK_DISABLE;
	}

	if (led_cdev->brightness_set)
	led_cdev->brightness_set(led_cdev, led_cdev->delayed_set_value);
	else if (led_cdev->brightness_set_blocking)
	ret = led_cdev->brightness_set_blocking(led_cdev,
	led_cdev->delayed_set_value);
	else
	ret = -ENOTSUPP;
	if (ret < 0 &&
	/* LED HW might have been unplugged, therefore don't warn */
	!(ret == -ENODEV && (led_cdev->flags & LED_UNREGISTERING) &&
	(led_cdev->flags & LED_HW_PLUGGABLE)))
	dev_err(led_cdev->dev,
	"Setting an LED's brightness failed (%d)\n", ret);
	}

	static void led_set_software_blink(struct led_classdev *led_cdev,
	unsigned long delay_on,
	unsigned long delay_off)
	{
	int current_brightness;

	current_brightness = led_get_brightness(led_cdev);
	if (current_brightness)
	led_cdev->blink_brightness = current_brightness;
	if (!led_cdev->blink_brightness)
	led_cdev->blink_brightness = led_cdev->max_brightness;

	led_cdev->blink_delay_on = delay_on;
	led_cdev->blink_delay_off = delay_off;

	/* never on - just set to off */
	if (!delay_on) {
	led_set_brightness_nosleep(led_cdev, LED_OFF);
	return;
	}

	/* never off - just set to brightness */
	if (!delay_off) {
	led_set_brightness_nosleep(led_cdev,
	led_cdev->blink_brightness);
	return;
	}

	mod_timer(&led_cdev->blink_timer, jiffies + 1);
	}


	static void led_blink_setup(struct led_classdev *led_cdev,
	unsigned long *delay_on,
	unsigned long *delay_off)
	{
	if (!(led_cdev->flags & LED_BLINK_ONESHOT) &&
	led_cdev->blink_set &&
	!led_cdev->blink_set(led_cdev, delay_on, delay_off))
	return;

	/* blink with 1 Hz as default if nothing specified */
	if (!delay_on && !delay_off)
	delay_on = delay_off = 500;

	led_set_software_blink(led_cdev, delay_on, delay_off);
	}

	void led_init_core(struct led_classdev *led_cdev)
	{
	INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);

	setup_timer(&led_cdev->blink_timer, led_timer_function,
	(unsigned long)led_cdev);
	}
	EXPORT_SYMBOL_GPL(led_init_core);

	void led_blink_set(struct led_classdev *led_cdev,
	unsigned long *delay_on,
	unsigned long *delay_off)
	{
	del_timer_sync(&led_cdev->blink_timer);

	led_cdev->flags &= ~LED_BLINK_ONESHOT;
	led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;

	led_blink_setup(led_cdev, delay_on, delay_off);
	}
	EXPORT_SYMBOL_GPL(led_blink_set);

	void led_blink_set_oneshot(struct led_classdev *led_cdev,
	unsigned long *delay_on,
	unsigned long *delay_off,
	int invert)
	{
	if ((led_cdev->flags & LED_BLINK_ONESHOT) &&
	timer_pending(&led_cdev->blink_timer))
	return;

	led_cdev->flags \|= LED_BLINK_ONESHOT;
	led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;

	if (invert)
	led_cdev->flags \|= LED_BLINK_INVERT;
	else
	led_cdev->flags &= ~LED_BLINK_INVERT;

	led_blink_setup(led_cdev, delay_on, delay_off);
	}
	EXPORT_SYMBOL_GPL(led_blink_set_oneshot);

	void led_stop_software_blink(struct led_classdev *led_cdev)
	{
	del_timer_sync(&led_cdev->blink_timer);
	led_cdev->blink_delay_on = 0;
	led_cdev->blink_delay_off = 0;
	}
	EXPORT_SYMBOL_GPL(led_stop_software_blink);

	void led_set_brightness(struct led_classdev *led_cdev,
	enum led_brightness brightness)
	{
	/*
	* In case blinking is on delay brightness setting
	* until the next timer tick.
	*/
	if (led_cdev->blink_delay_on \|\| led_cdev->blink_delay_off) {
	/*
	* If we need to disable soft blinking delegate this to the
	* work queue task to avoid problems in case we are called
	* from hard irq context.
	*/
	if (brightness == LED_OFF) {
	led_cdev->flags \|= LED_BLINK_DISABLE;
	schedule_work(&led_cdev->set_brightness_work);
	} else {
	led_cdev->flags \|= LED_BLINK_BRIGHTNESS_CHANGE;
	led_cdev->blink_brightness = brightness;
	}
	return;
	}

	led_set_brightness_nosleep(led_cdev, brightness);
	}
	EXPORT_SYMBOL_GPL(led_set_brightness);

	void led_set_brightness_nopm(struct led_classdev *led_cdev,
	enum led_brightness value)
	{
	/* Use brightness_set op if available, it is guaranteed not to sleep */
	if (led_cdev->brightness_set) {
	led_cdev->brightness_set(led_cdev, value);
	return;
	}

	/* If brightness setting can sleep, delegate it to a work queue task */
	led_cdev->delayed_set_value = value;
	schedule_work(&led_cdev->set_brightness_work);
	}
	EXPORT_SYMBOL_GPL(led_set_brightness_nopm);

	void led_set_brightness_nosleep(struct led_classdev *led_cdev,
	enum led_brightness value)
	{
	led_cdev->brightness = min(value, led_cdev->max_brightness);

	if (led_cdev->flags & LED_SUSPENDED)
	return;

	led_set_brightness_nopm(led_cdev, led_cdev->brightness);
	}
	EXPORT_SYMBOL_GPL(led_set_brightness_nosleep);

	int led_set_brightness_sync(struct led_classdev *led_cdev,
	enum led_brightness value)
	{
	if (led_cdev->blink_delay_on \|\| led_cdev->blink_delay_off)
	return -EBUSY;

	led_cdev->brightness = min(value, led_cdev->max_brightness);

	if (led_cdev->flags & LED_SUSPENDED)
	return 0;

	if (led_cdev->brightness_set_blocking)
	return led_cdev->brightness_set_blocking(led_cdev,
	led_cdev->brightness);
	return -ENOTSUPP;
	}
	EXPORT_SYMBOL_GPL(led_set_brightness_sync);

	int led_update_brightness(struct led_classdev *led_cdev)
	{
	int ret = 0;

	if (led_cdev->brightness_get) {
	ret = led_cdev->brightness_get(led_cdev);
	if (ret >= 0) {
	led_cdev->brightness = ret;
	return 0;
	}
	}

	return ret;
	}
	EXPORT_SYMBOL_GPL(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);