[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 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)
		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);
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
757b06ae JA	28	static void led_timer_function(unsigned long data)
	29	{
	30	struct led_classdev led_cdev = (void )data;
	31	unsigned long brightness;
	32	unsigned long delay;
	33
	34	if (!led_cdev->blink_delay_on \|\| !led_cdev->blink_delay_off) {
81fe8e5b	35	led_set_brightness_nosleep(led_cdev, LED_OFF);
757b06ae JA	36	return;
	37	}
	38
	39	if (led_cdev->flags & LED_BLINK_ONESHOT_STOP) {
	40	led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
	41	return;
	42	}
	43
	44	brightness = led_get_brightness(led_cdev);
	45	if (!brightness) {
	46	/* Time to switch the LED on. */
757b06ae JA	47	brightness = led_cdev->blink_brightness;
	48	delay = led_cdev->blink_delay_on;
	49	} else {
	50	/* Store the current brightness value to be able
	51	* to restore it when the delay_off period is over.
f1e80c07 JA	52	* Do it only if there is no pending blink brightness
f1e80c07 JA	53	* change, to avoid overwriting the new value.
757b06ae	54	*/
f1e80c07 JA	55	if (!(led_cdev->flags & LED_BLINK_BRIGHTNESS_CHANGE))
	56	led_cdev->blink_brightness = brightness;
	57	else
	58	led_cdev->flags &= ~LED_BLINK_BRIGHTNESS_CHANGE;
757b06ae JA	59	brightness = LED_OFF;
	60	delay = led_cdev->blink_delay_off;
	61	}
	62
81fe8e5b	63	led_set_brightness_nosleep(led_cdev, brightness);
757b06ae JA	64
	65	/* Return in next iteration if led is in one-shot mode and we are in
	66	* the final blink state so that the led is toggled each delay_on +
	67	* delay_off milliseconds in worst case.
	68	*/
	69	if (led_cdev->flags & LED_BLINK_ONESHOT) {
	70	if (led_cdev->flags & LED_BLINK_INVERT) {
	71	if (brightness)
	72	led_cdev->flags \|= LED_BLINK_ONESHOT_STOP;
	73	} else {
	74	if (!brightness)
	75	led_cdev->flags \|= LED_BLINK_ONESHOT_STOP;
	76	}
	77	}
	78
	79	mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
	80	}
	81
	82	static void set_brightness_delayed(struct work_struct *ws)
	83	{
	84	struct led_classdev *led_cdev =
	85	container_of(ws, struct led_classdev, set_brightness_work);
1afcadfc	86	int ret = 0;
757b06ae	87
f1e80c07 JA	88	if (led_cdev->flags & LED_BLINK_DISABLE) {
	89	led_cdev->delayed_set_value = LED_OFF;
	90	led_stop_software_blink(led_cdev);
	91	led_cdev->flags &= ~LED_BLINK_DISABLE;
	92	}
757b06ae	93
1afcadfc JA	94	if (led_cdev->brightness_set)
	95	led_cdev->brightness_set(led_cdev, led_cdev->delayed_set_value);
	96	else if (led_cdev->brightness_set_blocking)
	97	ret = led_cdev->brightness_set_blocking(led_cdev,
	98	led_cdev->delayed_set_value);
	99	else
	100	ret = -ENOTSUPP;
	101	if (ret < 0)
	102	dev_err(led_cdev->dev,
	103	"Setting an LED's brightness failed (%d)\n", ret);
757b06ae JA	104	}
757b06ae JA	105
a403d930 BW	106	static void led_set_software_blink(struct led_classdev *led_cdev,
	107	unsigned long delay_on,
	108	unsigned long delay_off)
	109	{
	110	int current_brightness;
	111
	112	current_brightness = led_get_brightness(led_cdev);
	113	if (current_brightness)
	114	led_cdev->blink_brightness = current_brightness;
	115	if (!led_cdev->blink_brightness)
	116	led_cdev->blink_brightness = led_cdev->max_brightness;
	117
a403d930 BW	118	led_cdev->blink_delay_on = delay_on;
	119	led_cdev->blink_delay_off = delay_off;
	120
8d82fef8 SS	121	/* never on - just set to off */
8d82fef8 SS	122	if (!delay_on) {
81fe8e5b	123	led_set_brightness_nosleep(led_cdev, LED_OFF);
a403d930	124	return;
8d82fef8	125	}
a403d930 BW	126
	127	/* never off - just set to brightness */
	128	if (!delay_off) {
81fe8e5b JA	129	led_set_brightness_nosleep(led_cdev,
81fe8e5b JA	130	led_cdev->blink_brightness);
a403d930 BW	131	return;
	132	}
	133
9067359f	134	mod_timer(&led_cdev->blink_timer, jiffies + 1);
a403d930 BW	135	}
	136
	137
20c0e6b8	138	static void led_blink_setup(struct led_classdev *led_cdev,
5bb629c5 FB	139	unsigned long *delay_on,
5bb629c5 FB	140	unsigned long *delay_off)
a403d930	141	{
5bb629c5 FB	142	if (!(led_cdev->flags & LED_BLINK_ONESHOT) &&
5bb629c5 FB	143	led_cdev->blink_set &&
a403d930 BW	144	!led_cdev->blink_set(led_cdev, delay_on, delay_off))
	145	return;
	146
	147	/* blink with 1 Hz as default if nothing specified */
	148	if (!delay_on && !delay_off)
	149	delay_on = delay_off = 500;
	150
	151	led_set_software_blink(led_cdev, delay_on, delay_off);
	152	}
5bb629c5	153
757b06ae JA	154	void led_init_core(struct led_classdev *led_cdev)
	155	{
	156	INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);
	157
	158	setup_timer(&led_cdev->blink_timer, led_timer_function,
	159	(unsigned long)led_cdev);
	160	}
	161	EXPORT_SYMBOL_GPL(led_init_core);
	162
5bb629c5 FB	163	void led_blink_set(struct led_classdev *led_cdev,
	164	unsigned long *delay_on,
	165	unsigned long *delay_off)
	166	{
9067359f	167	del_timer_sync(&led_cdev->blink_timer);
5bb629c5 FB	168
	169	led_cdev->flags &= ~LED_BLINK_ONESHOT;
	170	led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
	171
	172	led_blink_setup(led_cdev, delay_on, delay_off);
	173	}
2806e2ff	174	EXPORT_SYMBOL_GPL(led_blink_set);
a403d930	175
5bb629c5 FB	176	void led_blink_set_oneshot(struct led_classdev *led_cdev,
	177	unsigned long *delay_on,
	178	unsigned long *delay_off,
	179	int invert)
	180	{
	181	if ((led_cdev->flags & LED_BLINK_ONESHOT) &&
9067359f	182	timer_pending(&led_cdev->blink_timer))
5bb629c5 FB	183	return;
	184
	185	led_cdev->flags \|= LED_BLINK_ONESHOT;
	186	led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
	187
	188	if (invert)
	189	led_cdev->flags \|= LED_BLINK_INVERT;
	190	else
	191	led_cdev->flags &= ~LED_BLINK_INVERT;
	192
	193	led_blink_setup(led_cdev, delay_on, delay_off);
	194	}
2806e2ff	195	EXPORT_SYMBOL_GPL(led_blink_set_oneshot);
5bb629c5	196
d23a22a7	197	void led_stop_software_blink(struct led_classdev *led_cdev)
a403d930	198	{
9067359f	199	del_timer_sync(&led_cdev->blink_timer);
43786482 FB	200	led_cdev->blink_delay_on = 0;
43786482 FB	201	led_cdev->blink_delay_off = 0;
d23a22a7 FB	202	}
	203	EXPORT_SYMBOL_GPL(led_stop_software_blink);
	204
	205	void led_set_brightness(struct led_classdev *led_cdev,
	206	enum led_brightness brightness)
	207	{
f1e80c07 JA	208	/*
	209	* In case blinking is on delay brightness setting
	210	* until the next timer tick.
	211	*/
d23a22a7	212	if (led_cdev->blink_delay_on \|\| led_cdev->blink_delay_off) {
f1e80c07 JA	213	/*
	214	* If we need to disable soft blinking delegate this to the
	215	* work queue task to avoid problems in case we are called
	216	* from hard irq context.
	217	*/
	218	if (brightness == LED_OFF) {
	219	led_cdev->flags \|= LED_BLINK_DISABLE;
76931edd	220	schedule_work(&led_cdev->set_brightness_work);
f1e80c07 JA	221	} else {
	222	led_cdev->flags \|= LED_BLINK_BRIGHTNESS_CHANGE;
	223	led_cdev->blink_brightness = brightness;
	224	}
d23a22a7 FB	225	return;
d23a22a7 FB	226	}
43786482	227
13ae79bb	228	led_set_brightness_nosleep(led_cdev, brightness);
a403d930	229	}
2806e2ff	230	EXPORT_SYMBOL_GPL(led_set_brightness);
3ef7de53	231
81fe8e5b JA	232	void led_set_brightness_nopm(struct led_classdev *led_cdev,
	233	enum led_brightness value)
	234	{
	235	/* Use brightness_set op if available, it is guaranteed not to sleep */
	236	if (led_cdev->brightness_set) {
	237	led_cdev->brightness_set(led_cdev, value);
	238	return;
	239	}
	240
	241	/* If brightness setting can sleep, delegate it to a work queue task */
	242	led_cdev->delayed_set_value = value;
	243	schedule_work(&led_cdev->set_brightness_work);
	244	}
	245	EXPORT_SYMBOL_GPL(led_set_brightness_nopm);
	246
	247	void led_set_brightness_nosleep(struct led_classdev *led_cdev,
	248	enum led_brightness value)
	249	{
	250	led_cdev->brightness = min(value, led_cdev->max_brightness);
	251
	252	if (led_cdev->flags & LED_SUSPENDED)
	253	return;
	254
	255	led_set_brightness_nopm(led_cdev, led_cdev->brightness);
	256	}
	257	EXPORT_SYMBOL_GPL(led_set_brightness_nosleep);
	258
13ae79bb JA	259	int led_set_brightness_sync(struct led_classdev *led_cdev,
	260	enum led_brightness value)
	261	{
	262	if (led_cdev->blink_delay_on \|\| led_cdev->blink_delay_off)
	263	return -EBUSY;
	264
	265	led_cdev->brightness = min(value, led_cdev->max_brightness);
	266
	267	if (led_cdev->flags & LED_SUSPENDED)
	268	return 0;
	269
	270	if (led_cdev->brightness_set_blocking)
	271	return led_cdev->brightness_set_blocking(led_cdev,
	272	led_cdev->brightness);
	273	return -ENOTSUPP;
	274	}
	275	EXPORT_SYMBOL_GPL(led_set_brightness_sync);
	276
3ef7de53 JA	277	int led_update_brightness(struct led_classdev *led_cdev)
	278	{
	279	int ret = 0;
	280
	281	if (led_cdev->brightness_get) {
	282	ret = led_cdev->brightness_get(led_cdev);
	283	if (ret >= 0) {
	284	led_cdev->brightness = ret;
	285	return 0;
	286	}
	287	}
	288
	289	return ret;
	290	}
2806e2ff	291	EXPORT_SYMBOL_GPL(led_update_brightness);
acd899e4 JA	292
	293	/* Caller must ensure led_cdev->led_access held */
	294	void led_sysfs_disable(struct led_classdev *led_cdev)
	295	{
	296	lockdep_assert_held(&led_cdev->led_access);
	297
	298	led_cdev->flags \|= LED_SYSFS_DISABLE;
	299	}
	300	EXPORT_SYMBOL_GPL(led_sysfs_disable);
	301
	302	/* Caller must ensure led_cdev->led_access held */
	303	void led_sysfs_enable(struct led_classdev *led_cdev)
	304	{
	305	lockdep_assert_held(&led_cdev->led_access);
	306
	307	led_cdev->flags &= ~LED_SYSFS_DISABLE;
	308	}
	309	EXPORT_SYMBOL_GPL(led_sysfs_enable);