[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);
		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;
	}

	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;
	}

	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_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);
757b06ae JA	56	return;
	57	}
	58
	59	if (led_cdev->flags & LED_BLINK_ONESHOT_STOP) {
	60	led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
	61	return;
	62	}
	63
	64	brightness = led_get_brightness(led_cdev);
	65	if (!brightness) {
	66	/* Time to switch the LED on. */
757b06ae JA	67	brightness = led_cdev->blink_brightness;
	68	delay = led_cdev->blink_delay_on;
	69	} else {
	70	/* Store the current brightness value to be able
	71	* to restore it when the delay_off period is over.
f1e80c07 JA	72	* Do it only if there is no pending blink brightness
f1e80c07 JA	73	* change, to avoid overwriting the new value.
757b06ae	74	*/
f1e80c07 JA	75	if (!(led_cdev->flags & LED_BLINK_BRIGHTNESS_CHANGE))
	76	led_cdev->blink_brightness = brightness;
	77	else
	78	led_cdev->flags &= ~LED_BLINK_BRIGHTNESS_CHANGE;
757b06ae JA	79	brightness = LED_OFF;
	80	delay = led_cdev->blink_delay_off;
	81	}
	82
81fe8e5b	83	led_set_brightness_nosleep(led_cdev, brightness);
757b06ae JA	84
	85	/* Return in next iteration if led is in one-shot mode and we are in
	86	* the final blink state so that the led is toggled each delay_on +
	87	* delay_off milliseconds in worst case.
	88	*/
	89	if (led_cdev->flags & LED_BLINK_ONESHOT) {
	90	if (led_cdev->flags & LED_BLINK_INVERT) {
	91	if (brightness)
	92	led_cdev->flags \|= LED_BLINK_ONESHOT_STOP;
	93	} else {
	94	if (!brightness)
	95	led_cdev->flags \|= LED_BLINK_ONESHOT_STOP;
	96	}
	97	}
	98
	99	mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
	100	}
	101
	102	static void set_brightness_delayed(struct work_struct *ws)
	103	{
	104	struct led_classdev *led_cdev =
	105	container_of(ws, struct led_classdev, set_brightness_work);
1afcadfc	106	int ret = 0;
757b06ae	107
f1e80c07 JA	108	if (led_cdev->flags & LED_BLINK_DISABLE) {
	109	led_cdev->delayed_set_value = LED_OFF;
	110	led_stop_software_blink(led_cdev);
	111	led_cdev->flags &= ~LED_BLINK_DISABLE;
	112	}
757b06ae	113
d4887af9 HK	114	ret = __led_set_brightness(led_cdev, led_cdev->delayed_set_value);
	115	if (ret == -ENOTSUPP)
	116	ret = __led_set_brightness_blocking(led_cdev,
	117	led_cdev->delayed_set_value);
d84d80f3 HK	118	if (ret < 0 &&
	119	/* LED HW might have been unplugged, therefore don't warn */
	120	!(ret == -ENODEV && (led_cdev->flags & LED_UNREGISTERING) &&
	121	(led_cdev->flags & LED_HW_PLUGGABLE)))
1afcadfc JA	122	dev_err(led_cdev->dev,
1afcadfc JA	123	"Setting an LED's brightness failed (%d)\n", ret);
757b06ae JA	124	}
757b06ae JA	125
a403d930 BW	126	static void led_set_software_blink(struct led_classdev *led_cdev,
	127	unsigned long delay_on,
	128	unsigned long delay_off)
	129	{
	130	int current_brightness;
	131
	132	current_brightness = led_get_brightness(led_cdev);
	133	if (current_brightness)
	134	led_cdev->blink_brightness = current_brightness;
	135	if (!led_cdev->blink_brightness)
	136	led_cdev->blink_brightness = led_cdev->max_brightness;
	137
a403d930 BW	138	led_cdev->blink_delay_on = delay_on;
	139	led_cdev->blink_delay_off = delay_off;
	140
8d82fef8 SS	141	/* never on - just set to off */
8d82fef8 SS	142	if (!delay_on) {
81fe8e5b	143	led_set_brightness_nosleep(led_cdev, LED_OFF);
a403d930	144	return;
8d82fef8	145	}
a403d930 BW	146
	147	/* never off - just set to brightness */
	148	if (!delay_off) {
81fe8e5b JA	149	led_set_brightness_nosleep(led_cdev,
81fe8e5b JA	150	led_cdev->blink_brightness);
a403d930 BW	151	return;
	152	}
	153
9067359f	154	mod_timer(&led_cdev->blink_timer, jiffies + 1);
a403d930 BW	155	}
	156
	157
20c0e6b8	158	static void led_blink_setup(struct led_classdev *led_cdev,
5bb629c5 FB	159	unsigned long *delay_on,
5bb629c5 FB	160	unsigned long *delay_off)
a403d930	161	{
5bb629c5 FB	162	if (!(led_cdev->flags & LED_BLINK_ONESHOT) &&
5bb629c5 FB	163	led_cdev->blink_set &&
a403d930 BW	164	!led_cdev->blink_set(led_cdev, delay_on, delay_off))
	165	return;
	166
	167	/* blink with 1 Hz as default if nothing specified */
	168	if (!delay_on && !delay_off)
	169	delay_on = delay_off = 500;
	170
	171	led_set_software_blink(led_cdev, delay_on, delay_off);
	172	}
5bb629c5	173
757b06ae JA	174	void led_init_core(struct led_classdev *led_cdev)
	175	{
	176	INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);
	177
	178	setup_timer(&led_cdev->blink_timer, led_timer_function,
	179	(unsigned long)led_cdev);
	180	}
	181	EXPORT_SYMBOL_GPL(led_init_core);
	182
5bb629c5 FB	183	void led_blink_set(struct led_classdev *led_cdev,
	184	unsigned long *delay_on,
	185	unsigned long *delay_off)
	186	{
9067359f	187	del_timer_sync(&led_cdev->blink_timer);
5bb629c5 FB	188
	189	led_cdev->flags &= ~LED_BLINK_ONESHOT;
	190	led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
	191
	192	led_blink_setup(led_cdev, delay_on, delay_off);
	193	}
2806e2ff	194	EXPORT_SYMBOL_GPL(led_blink_set);
a403d930	195
5bb629c5 FB	196	void led_blink_set_oneshot(struct led_classdev *led_cdev,
	197	unsigned long *delay_on,
	198	unsigned long *delay_off,
	199	int invert)
	200	{
	201	if ((led_cdev->flags & LED_BLINK_ONESHOT) &&
9067359f	202	timer_pending(&led_cdev->blink_timer))
5bb629c5 FB	203	return;
	204
	205	led_cdev->flags \|= LED_BLINK_ONESHOT;
	206	led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
	207
	208	if (invert)
	209	led_cdev->flags \|= LED_BLINK_INVERT;
	210	else
	211	led_cdev->flags &= ~LED_BLINK_INVERT;
	212
	213	led_blink_setup(led_cdev, delay_on, delay_off);
	214	}
2806e2ff	215	EXPORT_SYMBOL_GPL(led_blink_set_oneshot);
5bb629c5	216
d23a22a7	217	void led_stop_software_blink(struct led_classdev *led_cdev)
a403d930	218	{
9067359f	219	del_timer_sync(&led_cdev->blink_timer);
43786482 FB	220	led_cdev->blink_delay_on = 0;
43786482 FB	221	led_cdev->blink_delay_off = 0;
d23a22a7 FB	222	}
	223	EXPORT_SYMBOL_GPL(led_stop_software_blink);
	224
	225	void led_set_brightness(struct led_classdev *led_cdev,
	226	enum led_brightness brightness)
	227	{
f1e80c07 JA	228	/*
	229	* In case blinking is on delay brightness setting
	230	* until the next timer tick.
	231	*/
d23a22a7	232	if (led_cdev->blink_delay_on \|\| led_cdev->blink_delay_off) {
f1e80c07 JA	233	/*
	234	* If we need to disable soft blinking delegate this to the
	235	* work queue task to avoid problems in case we are called
	236	* from hard irq context.
	237	*/
	238	if (brightness == LED_OFF) {
	239	led_cdev->flags \|= LED_BLINK_DISABLE;
76931edd	240	schedule_work(&led_cdev->set_brightness_work);
f1e80c07 JA	241	} else {
	242	led_cdev->flags \|= LED_BLINK_BRIGHTNESS_CHANGE;
	243	led_cdev->blink_brightness = brightness;
	244	}
d23a22a7 FB	245	return;
d23a22a7 FB	246	}
43786482	247
13ae79bb	248	led_set_brightness_nosleep(led_cdev, brightness);
a403d930	249	}
2806e2ff	250	EXPORT_SYMBOL_GPL(led_set_brightness);
3ef7de53	251
81fe8e5b JA	252	void led_set_brightness_nopm(struct led_classdev *led_cdev,
	253	enum led_brightness value)
	254	{
	255	/* Use brightness_set op if available, it is guaranteed not to sleep */
d4887af9	256	if (!__led_set_brightness(led_cdev, value))
81fe8e5b	257	return;
81fe8e5b JA	258
	259	/* If brightness setting can sleep, delegate it to a work queue task */
	260	led_cdev->delayed_set_value = value;
	261	schedule_work(&led_cdev->set_brightness_work);
	262	}
	263	EXPORT_SYMBOL_GPL(led_set_brightness_nopm);
	264
	265	void led_set_brightness_nosleep(struct led_classdev *led_cdev,
	266	enum led_brightness value)
	267	{
	268	led_cdev->brightness = min(value, led_cdev->max_brightness);
	269
	270	if (led_cdev->flags & LED_SUSPENDED)
	271	return;
	272
	273	led_set_brightness_nopm(led_cdev, led_cdev->brightness);
	274	}
	275	EXPORT_SYMBOL_GPL(led_set_brightness_nosleep);
	276
13ae79bb JA	277	int led_set_brightness_sync(struct led_classdev *led_cdev,
	278	enum led_brightness value)
	279	{
	280	if (led_cdev->blink_delay_on \|\| led_cdev->blink_delay_off)
	281	return -EBUSY;
	282
	283	led_cdev->brightness = min(value, led_cdev->max_brightness);
	284
	285	if (led_cdev->flags & LED_SUSPENDED)
	286	return 0;
	287
d4887af9	288	return __led_set_brightness_blocking(led_cdev, led_cdev->brightness);
13ae79bb JA	289	}
	290	EXPORT_SYMBOL_GPL(led_set_brightness_sync);
	291
3ef7de53 JA	292	int led_update_brightness(struct led_classdev *led_cdev)
	293	{
	294	int ret = 0;
	295
	296	if (led_cdev->brightness_get) {
	297	ret = led_cdev->brightness_get(led_cdev);
	298	if (ret >= 0) {
	299	led_cdev->brightness = ret;
	300	return 0;
	301	}
	302	}
	303
	304	return ret;
	305	}
2806e2ff	306	EXPORT_SYMBOL_GPL(led_update_brightness);
acd899e4 JA	307
	308	/* Caller must ensure led_cdev->led_access held */
	309	void led_sysfs_disable(struct led_classdev *led_cdev)
	310	{
	311	lockdep_assert_held(&led_cdev->led_access);
	312
	313	led_cdev->flags \|= LED_SYSFS_DISABLE;
	314	}
	315	EXPORT_SYMBOL_GPL(led_sysfs_disable);
	316
	317	/* Caller must ensure led_cdev->led_access held */
	318	void led_sysfs_enable(struct led_classdev *led_cdev)
	319	{
	320	lockdep_assert_held(&led_cdev->led_access);
	321
	322	led_cdev->flags &= ~LED_SYSFS_DISABLE;
	323	}
	324	EXPORT_SYMBOL_GPL(led_sysfs_enable);