[linux.git] / drivers / leds / led-core.c

/*
 * LED Class Core
 *
 * Copyright 2005-2006 Openedhand Ltd.
 *
 * Author: Richard Purdie <[email protected]>
 *
 * 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 int __led_set_brightness(struct led_classdev *led_cdev,
				enum led_brightness value)
{
	if (!led_cdev->brightness_set)
		return -ENOTSUPP;

	led_cdev->brightness_set(led_cdev, value);

	return 0;
}

static int __led_set_brightness_blocking(struct led_classdev *led_cdev,
					 enum led_brightness value)
{
	if (!led_cdev->brightness_set_blocking)
		return -ENOTSUPP;

	return led_cdev->brightness_set_blocking(led_cdev, value);
}

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);
		clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
		return;
	}

	if (test_and_clear_bit(LED_BLINK_ONESHOT_STOP,
			       &led_cdev->work_flags)) {
		clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
		return;
	}

	brightness = led_get_brightness(led_cdev);
	if (!brightness) {
		/* Time to switch the LED on. */
		if (test_and_clear_bit(LED_BLINK_BRIGHTNESS_CHANGE,
					&led_cdev->work_flags))
			brightness = led_cdev->new_blink_brightness;
		else
			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.
		 */
		led_cdev->blink_brightness = brightness;
		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 (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags)) {
		if (test_bit(LED_BLINK_INVERT, &led_cdev->work_flags)) {
			if (brightness)
				set_bit(LED_BLINK_ONESHOT_STOP,
					&led_cdev->work_flags);
		} else {
			if (!brightness)
				set_bit(LED_BLINK_ONESHOT_STOP,
					&led_cdev->work_flags);
		}
	}

	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 (test_and_clear_bit(LED_BLINK_DISABLE, &led_cdev->work_flags)) {
		led_cdev->delayed_set_value = LED_OFF;
		led_stop_software_blink(led_cdev);
	}

	ret = __led_set_brightness(led_cdev, led_cdev->delayed_set_value);
	if (ret == -ENOTSUPP)
		ret = __led_set_brightness_blocking(led_cdev,
					led_cdev->delayed_set_value);
	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;
	}

	set_bit(LED_BLINK_SW, &led_cdev->work_flags);
	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 (!test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
	    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);

	clear_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags);
	clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags);

	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 (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
	     timer_pending(&led_cdev->blink_timer))
		return;

	set_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags);
	clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags);

	if (invert)
		set_bit(LED_BLINK_INVERT, &led_cdev->work_flags);
	else
		clear_bit(LED_BLINK_INVERT, &led_cdev->work_flags);

	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;
	clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
}
EXPORT_SYMBOL_GPL(led_stop_software_blink);

void led_set_brightness(struct led_classdev *led_cdev,
			enum led_brightness brightness)
{
	/*
	 * If software blink is active, delay brightness setting
	 * until the next timer tick.
	 */
	if (test_bit(LED_BLINK_SW, &led_cdev->work_flags)) {
		/*
		 * 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) {
			set_bit(LED_BLINK_DISABLE, &led_cdev->work_flags);
			schedule_work(&led_cdev->set_brightness_work);
		} else {
			set_bit(LED_BLINK_BRIGHTNESS_CHANGE,
				&led_cdev->work_flags);
			led_cdev->new_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_set_brightness(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;

	return __led_set_brightness_blocking(led_cdev, led_cdev->brightness);
}
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);
Commit	Line	Data
c72a1d60 RP	1	/*
	2	* LED Class Core
	3	*
	4	* Copyright 2005-2006 Openedhand Ltd.
	5	*
	6	* Author: Richard Purdie <[email protected]>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*
	12	*/
	13
	14	#include <linux/kernel.h>
04713306	15	#include <linux/leds.h>
c72a1d60 RP	16	#include <linux/list.h>
c72a1d60 RP	17	#include <linux/module.h>
04713306	18	#include <linux/mutex.h>
72f8da32	19	#include <linux/rwsem.h>
c72a1d60 RP	20	#include "leds.h"
c72a1d60 RP	21
72f8da32	22	DECLARE_RWSEM(leds_list_lock);
4d404fd5	23	EXPORT_SYMBOL_GPL(leds_list_lock);
c72a1d60	24
4d404fd5	25	LIST_HEAD(leds_list);
c72a1d60	26	EXPORT_SYMBOL_GPL(leds_list);
a403d930	27
d4887af9 HK	28	static int __led_set_brightness(struct led_classdev *led_cdev,
	29	enum led_brightness value)
	30	{
	31	if (!led_cdev->brightness_set)
	32	return -ENOTSUPP;
	33
	34	led_cdev->brightness_set(led_cdev, value);
	35
	36	return 0;
	37	}
	38
	39	static int __led_set_brightness_blocking(struct led_classdev *led_cdev,
	40	enum led_brightness value)
	41	{
	42	if (!led_cdev->brightness_set_blocking)
	43	return -ENOTSUPP;
	44
	45	return led_cdev->brightness_set_blocking(led_cdev, value);
	46	}
	47
757b06ae JA	48	static void led_timer_function(unsigned long data)
	49	{
	50	struct led_classdev led_cdev = (void )data;
	51	unsigned long brightness;
	52	unsigned long delay;
	53
	54	if (!led_cdev->blink_delay_on \|\| !led_cdev->blink_delay_off) {
81fe8e5b	55	led_set_brightness_nosleep(led_cdev, LED_OFF);
a9c6ce57	56	clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
757b06ae JA	57	return;
	58	}
	59
a9c6ce57 HG	60	if (test_and_clear_bit(LED_BLINK_ONESHOT_STOP,
	61	&led_cdev->work_flags)) {
	62	clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
757b06ae JA	63	return;
	64	}
	65
	66	brightness = led_get_brightness(led_cdev);
	67	if (!brightness) {
	68	/* Time to switch the LED on. */
eb1610b4 HG	69	if (test_and_clear_bit(LED_BLINK_BRIGHTNESS_CHANGE,
	70	&led_cdev->work_flags))
	71	brightness = led_cdev->new_blink_brightness;
	72	else
	73	brightness = led_cdev->blink_brightness;
757b06ae JA	74	delay = led_cdev->blink_delay_on;
	75	} else {
	76	/* Store the current brightness value to be able
	77	* to restore it when the delay_off period is over.
	78	*/
eb1610b4	79	led_cdev->blink_brightness = brightness;
757b06ae JA	80	brightness = LED_OFF;
	81	delay = led_cdev->blink_delay_off;
	82	}
	83
81fe8e5b	84	led_set_brightness_nosleep(led_cdev, brightness);
757b06ae JA	85
	86	/* Return in next iteration if led is in one-shot mode and we are in
	87	* the final blink state so that the led is toggled each delay_on +
	88	* delay_off milliseconds in worst case.
	89	*/
a9c6ce57 HG	90	if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags)) {
a9c6ce57 HG	91	if (test_bit(LED_BLINK_INVERT, &led_cdev->work_flags)) {
757b06ae	92	if (brightness)
a9c6ce57 HG	93	set_bit(LED_BLINK_ONESHOT_STOP,
a9c6ce57 HG	94	&led_cdev->work_flags);
757b06ae JA	95	} else {
757b06ae JA	96	if (!brightness)
a9c6ce57 HG	97	set_bit(LED_BLINK_ONESHOT_STOP,
a9c6ce57 HG	98	&led_cdev->work_flags);
757b06ae JA	99	}
	100	}
	101
	102	mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
	103	}
	104
	105	static void set_brightness_delayed(struct work_struct *ws)
	106	{
	107	struct led_classdev *led_cdev =
	108	container_of(ws, struct led_classdev, set_brightness_work);
1afcadfc	109	int ret = 0;
757b06ae	110
a9c6ce57	111	if (test_and_clear_bit(LED_BLINK_DISABLE, &led_cdev->work_flags)) {
f1e80c07 JA	112	led_cdev->delayed_set_value = LED_OFF;
f1e80c07 JA	113	led_stop_software_blink(led_cdev);
f1e80c07	114	}
757b06ae	115
d4887af9 HK	116	ret = __led_set_brightness(led_cdev, led_cdev->delayed_set_value);
	117	if (ret == -ENOTSUPP)
	118	ret = __led_set_brightness_blocking(led_cdev,
	119	led_cdev->delayed_set_value);
d84d80f3 HK	120	if (ret < 0 &&
	121	/* LED HW might have been unplugged, therefore don't warn */
	122	!(ret == -ENODEV && (led_cdev->flags & LED_UNREGISTERING) &&
	123	(led_cdev->flags & LED_HW_PLUGGABLE)))
1afcadfc JA	124	dev_err(led_cdev->dev,
1afcadfc JA	125	"Setting an LED's brightness failed (%d)\n", ret);
757b06ae JA	126	}
757b06ae JA	127
a403d930 BW	128	static void led_set_software_blink(struct led_classdev *led_cdev,
	129	unsigned long delay_on,
	130	unsigned long delay_off)
	131	{
	132	int current_brightness;
	133
	134	current_brightness = led_get_brightness(led_cdev);
	135	if (current_brightness)
	136	led_cdev->blink_brightness = current_brightness;
	137	if (!led_cdev->blink_brightness)
	138	led_cdev->blink_brightness = led_cdev->max_brightness;
	139
a403d930 BW	140	led_cdev->blink_delay_on = delay_on;
	141	led_cdev->blink_delay_off = delay_off;
	142
8d82fef8 SS	143	/* never on - just set to off */
8d82fef8 SS	144	if (!delay_on) {
81fe8e5b	145	led_set_brightness_nosleep(led_cdev, LED_OFF);
a403d930	146	return;
8d82fef8	147	}
a403d930 BW	148
	149	/* never off - just set to brightness */
	150	if (!delay_off) {
81fe8e5b JA	151	led_set_brightness_nosleep(led_cdev,
81fe8e5b JA	152	led_cdev->blink_brightness);
a403d930 BW	153	return;
	154	}
	155
a9c6ce57	156	set_bit(LED_BLINK_SW, &led_cdev->work_flags);
9067359f	157	mod_timer(&led_cdev->blink_timer, jiffies + 1);
a403d930 BW	158	}
	159
	160
20c0e6b8	161	static void led_blink_setup(struct led_classdev *led_cdev,
5bb629c5 FB	162	unsigned long *delay_on,
5bb629c5 FB	163	unsigned long *delay_off)
a403d930	164	{
a9c6ce57	165	if (!test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
5bb629c5	166	led_cdev->blink_set &&
a403d930 BW	167	!led_cdev->blink_set(led_cdev, delay_on, delay_off))
	168	return;
	169
	170	/* blink with 1 Hz as default if nothing specified */
	171	if (!delay_on && !delay_off)
	172	delay_on = delay_off = 500;
	173
	174	led_set_software_blink(led_cdev, delay_on, delay_off);
	175	}
5bb629c5	176
757b06ae JA	177	void led_init_core(struct led_classdev *led_cdev)
	178	{
	179	INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);
	180
	181	setup_timer(&led_cdev->blink_timer, led_timer_function,
	182	(unsigned long)led_cdev);
	183	}
	184	EXPORT_SYMBOL_GPL(led_init_core);
	185
5bb629c5 FB	186	void led_blink_set(struct led_classdev *led_cdev,
	187	unsigned long *delay_on,
	188	unsigned long *delay_off)
	189	{
9067359f	190	del_timer_sync(&led_cdev->blink_timer);
5bb629c5	191
a9c6ce57 HG	192	clear_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags);
a9c6ce57 HG	193	clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags);
5bb629c5 FB	194
	195	led_blink_setup(led_cdev, delay_on, delay_off);
	196	}
2806e2ff	197	EXPORT_SYMBOL_GPL(led_blink_set);
a403d930	198
5bb629c5 FB	199	void led_blink_set_oneshot(struct led_classdev *led_cdev,
	200	unsigned long *delay_on,
	201	unsigned long *delay_off,
	202	int invert)
	203	{
a9c6ce57	204	if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
9067359f	205	timer_pending(&led_cdev->blink_timer))
5bb629c5 FB	206	return;
5bb629c5 FB	207
a9c6ce57 HG	208	set_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags);
a9c6ce57 HG	209	clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags);
5bb629c5 FB	210
5bb629c5 FB	211	if (invert)
a9c6ce57	212	set_bit(LED_BLINK_INVERT, &led_cdev->work_flags);
5bb629c5	213	else
a9c6ce57	214	clear_bit(LED_BLINK_INVERT, &led_cdev->work_flags);
5bb629c5 FB	215
	216	led_blink_setup(led_cdev, delay_on, delay_off);
	217	}
2806e2ff	218	EXPORT_SYMBOL_GPL(led_blink_set_oneshot);
5bb629c5	219
d23a22a7	220	void led_stop_software_blink(struct led_classdev *led_cdev)
a403d930	221	{
9067359f	222	del_timer_sync(&led_cdev->blink_timer);
43786482 FB	223	led_cdev->blink_delay_on = 0;
43786482 FB	224	led_cdev->blink_delay_off = 0;
a9c6ce57	225	clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
d23a22a7 FB	226	}
	227	EXPORT_SYMBOL_GPL(led_stop_software_blink);
	228
	229	void led_set_brightness(struct led_classdev *led_cdev,
	230	enum led_brightness brightness)
	231	{
f1e80c07	232	/*
7cfe749f	233	* If software blink is active, delay brightness setting
f1e80c07 JA	234	* until the next timer tick.
f1e80c07 JA	235	*/
a9c6ce57	236	if (test_bit(LED_BLINK_SW, &led_cdev->work_flags)) {
f1e80c07 JA	237	/*
	238	* If we need to disable soft blinking delegate this to the
	239	* work queue task to avoid problems in case we are called
	240	* from hard irq context.
	241	*/
	242	if (brightness == LED_OFF) {
a9c6ce57	243	set_bit(LED_BLINK_DISABLE, &led_cdev->work_flags);
76931edd	244	schedule_work(&led_cdev->set_brightness_work);
f1e80c07	245	} else {
a9c6ce57 HG	246	set_bit(LED_BLINK_BRIGHTNESS_CHANGE,
a9c6ce57 HG	247	&led_cdev->work_flags);
eb1610b4	248	led_cdev->new_blink_brightness = brightness;
f1e80c07	249	}
d23a22a7 FB	250	return;
d23a22a7 FB	251	}
43786482	252
13ae79bb	253	led_set_brightness_nosleep(led_cdev, brightness);
a403d930	254	}
2806e2ff	255	EXPORT_SYMBOL_GPL(led_set_brightness);
3ef7de53	256
81fe8e5b JA	257	void led_set_brightness_nopm(struct led_classdev *led_cdev,
	258	enum led_brightness value)
	259	{
	260	/* Use brightness_set op if available, it is guaranteed not to sleep */
d4887af9	261	if (!__led_set_brightness(led_cdev, value))
81fe8e5b	262	return;
81fe8e5b JA	263
	264	/* If brightness setting can sleep, delegate it to a work queue task */
	265	led_cdev->delayed_set_value = value;
	266	schedule_work(&led_cdev->set_brightness_work);
	267	}
	268	EXPORT_SYMBOL_GPL(led_set_brightness_nopm);
	269
	270	void led_set_brightness_nosleep(struct led_classdev *led_cdev,
	271	enum led_brightness value)
	272	{
	273	led_cdev->brightness = min(value, led_cdev->max_brightness);
	274
	275	if (led_cdev->flags & LED_SUSPENDED)
	276	return;
	277
	278	led_set_brightness_nopm(led_cdev, led_cdev->brightness);
	279	}
	280	EXPORT_SYMBOL_GPL(led_set_brightness_nosleep);
	281
13ae79bb JA	282	int led_set_brightness_sync(struct led_classdev *led_cdev,
	283	enum led_brightness value)
	284	{
	285	if (led_cdev->blink_delay_on \|\| led_cdev->blink_delay_off)
	286	return -EBUSY;
	287
	288	led_cdev->brightness = min(value, led_cdev->max_brightness);
	289
	290	if (led_cdev->flags & LED_SUSPENDED)
	291	return 0;
	292
d4887af9	293	return __led_set_brightness_blocking(led_cdev, led_cdev->brightness);
13ae79bb JA	294	}
	295	EXPORT_SYMBOL_GPL(led_set_brightness_sync);
	296
3ef7de53 JA	297	int led_update_brightness(struct led_classdev *led_cdev)
	298	{
	299	int ret = 0;
	300
	301	if (led_cdev->brightness_get) {
	302	ret = led_cdev->brightness_get(led_cdev);
	303	if (ret >= 0) {
	304	led_cdev->brightness = ret;
	305	return 0;
	306	}
	307	}
	308
	309	return ret;
	310	}
2806e2ff	311	EXPORT_SYMBOL_GPL(led_update_brightness);
acd899e4 JA	312
	313	/* Caller must ensure led_cdev->led_access held */
	314	void led_sysfs_disable(struct led_classdev *led_cdev)
	315	{
	316	lockdep_assert_held(&led_cdev->led_access);
	317
	318	led_cdev->flags \|= LED_SYSFS_DISABLE;
	319	}
	320	EXPORT_SYMBOL_GPL(led_sysfs_disable);
	321
	322	/* Caller must ensure led_cdev->led_access held */
	323	void led_sysfs_enable(struct led_classdev *led_cdev)
	324	{
	325	lockdep_assert_held(&led_cdev->led_access);
	326
	327	led_cdev->flags &= ~LED_SYSFS_DISABLE;
	328	}
	329	EXPORT_SYMBOL_GPL(led_sysfs_enable);