[linux-2.6-block.git] / drivers / leds / led-triggers.c

/*
 * LED Triggers Core
 *
 * Copyright 2005-2007 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/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/timer.h>
#include <linux/rwsem.h>
#include <linux/leds.h>
#include <linux/slab.h>
#include "leds.h"

/*
 * Nests outside led_cdev->trigger_lock
 */
static DECLARE_RWSEM(triggers_list_lock);
static LIST_HEAD(trigger_list);

 /* Used by LED Class */

ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	char trigger_name[TRIG_NAME_MAX];
	struct led_trigger *trig;
	size_t len;

	trigger_name[sizeof(trigger_name) - 1] = '\0';
	strncpy(trigger_name, buf, sizeof(trigger_name) - 1);
	len = strlen(trigger_name);

	if (len && trigger_name[len - 1] == '\n')
		trigger_name[len - 1] = '\0';

	if (!strcmp(trigger_name, "none")) {
		led_trigger_remove(led_cdev);
		return count;
	}

	down_read(&triggers_list_lock);
	list_for_each_entry(trig, &trigger_list, next_trig) {
		if (!strcmp(trigger_name, trig->name)) {
			down_write(&led_cdev->trigger_lock);
			led_trigger_set(led_cdev, trig);
			up_write(&led_cdev->trigger_lock);

			up_read(&triggers_list_lock);
			return count;
		}
	}
	up_read(&triggers_list_lock);

	return -EINVAL;
}
EXPORT_SYMBOL_GPL(led_trigger_store);

ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	struct led_trigger *trig;
	int len = 0;

	down_read(&triggers_list_lock);
	down_read(&led_cdev->trigger_lock);

	if (!led_cdev->trigger)
		len += sprintf(buf+len, "[none] ");
	else
		len += sprintf(buf+len, "none ");

	list_for_each_entry(trig, &trigger_list, next_trig) {
		if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
							trig->name))
			len += sprintf(buf+len, "[%s] ", trig->name);
		else
			len += sprintf(buf+len, "%s ", trig->name);
	}
	up_read(&led_cdev->trigger_lock);
	up_read(&triggers_list_lock);

	len += sprintf(len+buf, "\n");
	return len;
}
EXPORT_SYMBOL_GPL(led_trigger_show);

/* Caller must ensure led_cdev->trigger_lock held */
void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
{
	unsigned long flags;

	/* Remove any existing trigger */
	if (led_cdev->trigger) {
		write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
		list_del(&led_cdev->trig_list);
		write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
			flags);
		cancel_work_sync(&led_cdev->set_brightness_work);
		led_stop_software_blink(led_cdev);
		if (led_cdev->trigger->deactivate)
			led_cdev->trigger->deactivate(led_cdev);
		led_cdev->trigger = NULL;
		led_set_brightness(led_cdev, LED_OFF);
	}
	if (trig) {
		write_lock_irqsave(&trig->leddev_list_lock, flags);
		list_add_tail(&led_cdev->trig_list, &trig->led_cdevs);
		write_unlock_irqrestore(&trig->leddev_list_lock, flags);
		led_cdev->trigger = trig;
		if (trig->activate)
			trig->activate(led_cdev);
	}
}
EXPORT_SYMBOL_GPL(led_trigger_set);

void led_trigger_remove(struct led_classdev *led_cdev)
{
	down_write(&led_cdev->trigger_lock);
	led_trigger_set(led_cdev, NULL);
	up_write(&led_cdev->trigger_lock);
}
EXPORT_SYMBOL_GPL(led_trigger_remove);

void led_trigger_set_default(struct led_classdev *led_cdev)
{
	struct led_trigger *trig;

	if (!led_cdev->default_trigger)
		return;

	down_read(&triggers_list_lock);
	down_write(&led_cdev->trigger_lock);
	list_for_each_entry(trig, &trigger_list, next_trig) {
		if (!strcmp(led_cdev->default_trigger, trig->name))
			led_trigger_set(led_cdev, trig);
	}
	up_write(&led_cdev->trigger_lock);
	up_read(&triggers_list_lock);
}
EXPORT_SYMBOL_GPL(led_trigger_set_default);

/* LED Trigger Interface */

int led_trigger_register(struct led_trigger *trig)
{
	struct led_classdev *led_cdev;
	struct led_trigger *_trig;

	rwlock_init(&trig->leddev_list_lock);
	INIT_LIST_HEAD(&trig->led_cdevs);

	down_write(&triggers_list_lock);
	/* Make sure the trigger's name isn't already in use */
	list_for_each_entry(_trig, &trigger_list, next_trig) {
		if (!strcmp(_trig->name, trig->name)) {
			up_write(&triggers_list_lock);
			return -EEXIST;
		}
	}
	/* Add to the list of led triggers */
	list_add_tail(&trig->next_trig, &trigger_list);
	up_write(&triggers_list_lock);

	/* Register with any LEDs that have this as a default trigger */
	down_read(&leds_list_lock);
	list_for_each_entry(led_cdev, &leds_list, node) {
		down_write(&led_cdev->trigger_lock);
		if (!led_cdev->trigger && led_cdev->default_trigger &&
			    !strcmp(led_cdev->default_trigger, trig->name))
			led_trigger_set(led_cdev, trig);
		up_write(&led_cdev->trigger_lock);
	}
	up_read(&leds_list_lock);

	return 0;
}
EXPORT_SYMBOL_GPL(led_trigger_register);

void led_trigger_unregister(struct led_trigger *trig)
{
	struct led_classdev *led_cdev;

	/* Remove from the list of led triggers */
	down_write(&triggers_list_lock);
	list_del(&trig->next_trig);
	up_write(&triggers_list_lock);

	/* Remove anyone actively using this trigger */
	down_read(&leds_list_lock);
	list_for_each_entry(led_cdev, &leds_list, node) {
		down_write(&led_cdev->trigger_lock);
		if (led_cdev->trigger == trig)
			led_trigger_set(led_cdev, NULL);
		up_write(&led_cdev->trigger_lock);
	}
	up_read(&leds_list_lock);
}
EXPORT_SYMBOL_GPL(led_trigger_unregister);

/* Simple LED Tigger Interface */

void led_trigger_event(struct led_trigger *trig,
			enum led_brightness brightness)
{
	struct list_head *entry;

	if (!trig)
		return;

	read_lock(&trig->leddev_list_lock);
	list_for_each(entry, &trig->led_cdevs) {
		struct led_classdev *led_cdev;

		led_cdev = list_entry(entry, struct led_classdev, trig_list);
		led_set_brightness(led_cdev, brightness);
	}
	read_unlock(&trig->leddev_list_lock);
}
EXPORT_SYMBOL_GPL(led_trigger_event);

static void led_trigger_blink_setup(struct led_trigger *trig,
			     unsigned long *delay_on,
			     unsigned long *delay_off,
			     int oneshot,
			     int invert)
{
	struct list_head *entry;

	if (!trig)
		return;

	read_lock(&trig->leddev_list_lock);
	list_for_each(entry, &trig->led_cdevs) {
		struct led_classdev *led_cdev;

		led_cdev = list_entry(entry, struct led_classdev, trig_list);
		if (oneshot)
			led_blink_set_oneshot(led_cdev, delay_on, delay_off,
					      invert);
		else
			led_blink_set(led_cdev, delay_on, delay_off);
	}
	read_unlock(&trig->leddev_list_lock);
}

void led_trigger_blink(struct led_trigger *trig,
		       unsigned long *delay_on,
		       unsigned long *delay_off)
{
	led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
}
EXPORT_SYMBOL_GPL(led_trigger_blink);

void led_trigger_blink_oneshot(struct led_trigger *trig,
			       unsigned long *delay_on,
			       unsigned long *delay_off,
			       int invert)
{
	led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);
}
EXPORT_SYMBOL_GPL(led_trigger_blink_oneshot);

void led_trigger_register_simple(const char *name, struct led_trigger **tp)
{
	struct led_trigger *trig;
	int err;

	trig = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);

	if (trig) {
		trig->name = name;
		err = led_trigger_register(trig);
		if (err < 0) {
			kfree(trig);
			trig = NULL;
			printk(KERN_WARNING "LED trigger %s failed to register"
				" (%d)\n", name, err);
		}
	} else
		printk(KERN_WARNING "LED trigger %s failed to register"
			" (no memory)\n", name);

	*tp = trig;
}
EXPORT_SYMBOL_GPL(led_trigger_register_simple);

void led_trigger_unregister_simple(struct led_trigger *trig)
{
	if (trig)
		led_trigger_unregister(trig);
	kfree(trig);
}
EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);

MODULE_AUTHOR("Richard Purdie");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("LED Triggers Core");
Commit	Line	Data
c3bc9956 RP	1	/*
	2	* LED Triggers Core
	3	*
f8a7c6fe	4	* Copyright 2005-2007 Openedhand Ltd.
c3bc9956 RP	5	*
	6	* Author: Richard Purdie <rpurdie@openedhand.com>
	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
c3bc9956 RP	14	#include <linux/module.h>
	15	#include <linux/kernel.h>
	16	#include <linux/init.h>
	17	#include <linux/list.h>
	18	#include <linux/spinlock.h>
	19	#include <linux/device.h>
c3bc9956	20	#include <linux/timer.h>
dc47206e	21	#include <linux/rwsem.h>
c3bc9956	22	#include <linux/leds.h>
5a0e3ad6	23	#include <linux/slab.h>
c3bc9956 RP	24	#include "leds.h"
	25
	26	/*
	27	* Nests outside led_cdev->trigger_lock
	28	*/
dc47206e	29	static DECLARE_RWSEM(triggers_list_lock);
c3bc9956 RP	30	static LIST_HEAD(trigger_list);
c3bc9956 RP	31
4d404fd5 NM	32	/* Used by LED Class */
4d404fd5 NM	33
f8a7c6fe RP	34	ssize_t led_trigger_store(struct device dev, struct device_attribute attr,
f8a7c6fe RP	35	const char *buf, size_t count)
c3bc9956	36	{
f8a7c6fe	37	struct led_classdev *led_cdev = dev_get_drvdata(dev);
c3bc9956 RP	38	char trigger_name[TRIG_NAME_MAX];
	39	struct led_trigger *trig;
	40	size_t len;
	41
	42	trigger_name[sizeof(trigger_name) - 1] = '\0';
	43	strncpy(trigger_name, buf, sizeof(trigger_name) - 1);
	44	len = strlen(trigger_name);
	45
	46	if (len && trigger_name[len - 1] == '\n')
	47	trigger_name[len - 1] = '\0';
	48
	49	if (!strcmp(trigger_name, "none")) {
0013b23d	50	led_trigger_remove(led_cdev);
c3bc9956 RP	51	return count;
	52	}
	53
dc47206e	54	down_read(&triggers_list_lock);
c3bc9956 RP	55	list_for_each_entry(trig, &trigger_list, next_trig) {
c3bc9956 RP	56	if (!strcmp(trigger_name, trig->name)) {
dc47206e	57	down_write(&led_cdev->trigger_lock);
c3bc9956	58	led_trigger_set(led_cdev, trig);
dc47206e	59	up_write(&led_cdev->trigger_lock);
c3bc9956	60
dc47206e	61	up_read(&triggers_list_lock);
c3bc9956 RP	62	return count;
	63	}
	64	}
dc47206e	65	up_read(&triggers_list_lock);
c3bc9956 RP	66
	67	return -EINVAL;
	68	}
4d404fd5	69	EXPORT_SYMBOL_GPL(led_trigger_store);
c3bc9956	70
f8a7c6fe RP	71	ssize_t led_trigger_show(struct device dev, struct device_attribute attr,
f8a7c6fe RP	72	char *buf)
c3bc9956	73	{
f8a7c6fe	74	struct led_classdev *led_cdev = dev_get_drvdata(dev);
c3bc9956 RP	75	struct led_trigger *trig;
	76	int len = 0;
	77
dc47206e RP	78	down_read(&triggers_list_lock);
dc47206e RP	79	down_read(&led_cdev->trigger_lock);
c3bc9956 RP	80
	81	if (!led_cdev->trigger)
	82	len += sprintf(buf+len, "[none] ");
	83	else
	84	len += sprintf(buf+len, "none ");
	85
	86	list_for_each_entry(trig, &trigger_list, next_trig) {
	87	if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
	88	trig->name))
	89	len += sprintf(buf+len, "[%s] ", trig->name);
	90	else
	91	len += sprintf(buf+len, "%s ", trig->name);
	92	}
dc47206e RP	93	up_read(&led_cdev->trigger_lock);
dc47206e RP	94	up_read(&triggers_list_lock);
c3bc9956 RP	95
	96	len += sprintf(len+buf, "\n");
	97	return len;
	98	}
4d404fd5	99	EXPORT_SYMBOL_GPL(led_trigger_show);
c3bc9956 RP	100
c3bc9956 RP	101	/* Caller must ensure led_cdev->trigger_lock held */
eb202621	102	void led_trigger_set(struct led_classdev led_cdev, struct led_trigger trig)
c3bc9956 RP	103	{
	104	unsigned long flags;
	105
	106	/* Remove any existing trigger */
	107	if (led_cdev->trigger) {
	108	write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
	109	list_del(&led_cdev->trig_list);
4d404fd5 NM	110	write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
4d404fd5 NM	111	flags);
d23a22a7 FB	112	cancel_work_sync(&led_cdev->set_brightness_work);
d23a22a7 FB	113	led_stop_software_blink(led_cdev);
c3bc9956 RP	114	if (led_cdev->trigger->deactivate)
c3bc9956 RP	115	led_cdev->trigger->deactivate(led_cdev);
fe3025b5	116	led_cdev->trigger = NULL;
19cd67e2	117	led_set_brightness(led_cdev, LED_OFF);
c3bc9956	118	}
eb202621 BW	119	if (trig) {
	120	write_lock_irqsave(&trig->leddev_list_lock, flags);
	121	list_add_tail(&led_cdev->trig_list, &trig->led_cdevs);
	122	write_unlock_irqrestore(&trig->leddev_list_lock, flags);
	123	led_cdev->trigger = trig;
	124	if (trig->activate)
	125	trig->activate(led_cdev);
c3bc9956	126	}
c3bc9956	127	}
4d404fd5	128	EXPORT_SYMBOL_GPL(led_trigger_set);
c3bc9956	129
0013b23d NM	130	void led_trigger_remove(struct led_classdev *led_cdev)
	131	{
	132	down_write(&led_cdev->trigger_lock);
	133	led_trigger_set(led_cdev, NULL);
	134	up_write(&led_cdev->trigger_lock);
	135	}
4d404fd5	136	EXPORT_SYMBOL_GPL(led_trigger_remove);
0013b23d	137
c3bc9956 RP	138	void led_trigger_set_default(struct led_classdev *led_cdev)
	139	{
	140	struct led_trigger *trig;
	141
	142	if (!led_cdev->default_trigger)
	143	return;
	144
dc47206e RP	145	down_read(&triggers_list_lock);
dc47206e RP	146	down_write(&led_cdev->trigger_lock);
c3bc9956 RP	147	list_for_each_entry(trig, &trigger_list, next_trig) {
	148	if (!strcmp(led_cdev->default_trigger, trig->name))
	149	led_trigger_set(led_cdev, trig);
	150	}
dc47206e RP	151	up_write(&led_cdev->trigger_lock);
dc47206e RP	152	up_read(&triggers_list_lock);
c3bc9956	153	}
4d404fd5 NM	154	EXPORT_SYMBOL_GPL(led_trigger_set_default);
	155
	156	/* LED Trigger Interface */
c3bc9956	157
eb202621	158	int led_trigger_register(struct led_trigger *trig)
c3bc9956 RP	159	{
c3bc9956 RP	160	struct led_classdev *led_cdev;
eb202621	161	struct led_trigger *_trig;
c3bc9956	162
eb202621 BW	163	rwlock_init(&trig->leddev_list_lock);
eb202621 BW	164	INIT_LIST_HEAD(&trig->led_cdevs);
c3bc9956	165
dc47206e	166	down_write(&triggers_list_lock);
700c6ea2	167	/* Make sure the trigger's name isn't already in use */
eb202621 BW	168	list_for_each_entry(_trig, &trigger_list, next_trig) {
eb202621 BW	169	if (!strcmp(_trig->name, trig->name)) {
700c6ea2 AN	170	up_write(&triggers_list_lock);
	171	return -EEXIST;
	172	}
	173	}
	174	/* Add to the list of led triggers */
eb202621	175	list_add_tail(&trig->next_trig, &trigger_list);
dc47206e	176	up_write(&triggers_list_lock);
c3bc9956 RP	177
c3bc9956 RP	178	/* Register with any LEDs that have this as a default trigger */
72f8da32	179	down_read(&leds_list_lock);
c3bc9956	180	list_for_each_entry(led_cdev, &leds_list, node) {
dc47206e	181	down_write(&led_cdev->trigger_lock);
c3bc9956	182	if (!led_cdev->trigger && led_cdev->default_trigger &&
eb202621 BW	183	!strcmp(led_cdev->default_trigger, trig->name))
eb202621 BW	184	led_trigger_set(led_cdev, trig);
dc47206e	185	up_write(&led_cdev->trigger_lock);
c3bc9956	186	}
72f8da32	187	up_read(&leds_list_lock);
c3bc9956 RP	188
	189	return 0;
	190	}
4d404fd5	191	EXPORT_SYMBOL_GPL(led_trigger_register);
c3bc9956	192
eb202621	193	void led_trigger_unregister(struct led_trigger *trig)
c3bc9956 RP	194	{
	195	struct led_classdev *led_cdev;
	196
	197	/* Remove from the list of led triggers */
dc47206e	198	down_write(&triggers_list_lock);
eb202621	199	list_del(&trig->next_trig);
dc47206e	200	up_write(&triggers_list_lock);
c3bc9956 RP	201
c3bc9956 RP	202	/* Remove anyone actively using this trigger */
72f8da32	203	down_read(&leds_list_lock);
c3bc9956	204	list_for_each_entry(led_cdev, &leds_list, node) {
dc47206e	205	down_write(&led_cdev->trigger_lock);
eb202621	206	if (led_cdev->trigger == trig)
c3bc9956	207	led_trigger_set(led_cdev, NULL);
dc47206e	208	up_write(&led_cdev->trigger_lock);
c3bc9956	209	}
72f8da32	210	up_read(&leds_list_lock);
c3bc9956	211	}
4d404fd5	212	EXPORT_SYMBOL_GPL(led_trigger_unregister);
c3bc9956	213
4d404fd5 NM	214	/* Simple LED Tigger Interface */
4d404fd5 NM	215
eb202621	216	void led_trigger_event(struct led_trigger *trig,
4d404fd5	217	enum led_brightness brightness)
c3bc9956	218	{
4d404fd5 NM	219	struct list_head *entry;
4d404fd5 NM	220
eb202621	221	if (!trig)
4d404fd5 NM	222	return;
4d404fd5 NM	223
eb202621 BW	224	read_lock(&trig->leddev_list_lock);
eb202621 BW	225	list_for_each(entry, &trig->led_cdevs) {
4d404fd5 NM	226	struct led_classdev *led_cdev;
	227
	228	led_cdev = list_entry(entry, struct led_classdev, trig_list);
d23a22a7	229	led_set_brightness(led_cdev, brightness);
4d404fd5	230	}
eb202621	231	read_unlock(&trig->leddev_list_lock);
c3bc9956	232	}
4d404fd5	233	EXPORT_SYMBOL_GPL(led_trigger_event);
c3bc9956	234
20c0e6b8	235	static void led_trigger_blink_setup(struct led_trigger *trig,
5bb629c5 FB	236	unsigned long *delay_on,
	237	unsigned long *delay_off,
	238	int oneshot,
	239	int invert)
0b9536c9 VK	240	{
	241	struct list_head *entry;
	242
eb202621	243	if (!trig)
0b9536c9 VK	244	return;
0b9536c9 VK	245
eb202621 BW	246	read_lock(&trig->leddev_list_lock);
eb202621 BW	247	list_for_each(entry, &trig->led_cdevs) {
0b9536c9 VK	248	struct led_classdev *led_cdev;
	249
	250	led_cdev = list_entry(entry, struct led_classdev, trig_list);
5bb629c5 FB	251	if (oneshot)
	252	led_blink_set_oneshot(led_cdev, delay_on, delay_off,
	253	invert);
	254	else
	255	led_blink_set(led_cdev, delay_on, delay_off);
0b9536c9	256	}
eb202621	257	read_unlock(&trig->leddev_list_lock);
0b9536c9	258	}
5bb629c5 FB	259
	260	void led_trigger_blink(struct led_trigger *trig,
	261	unsigned long *delay_on,
	262	unsigned long *delay_off)
	263	{
	264	led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
	265	}
0b9536c9 VK	266	EXPORT_SYMBOL_GPL(led_trigger_blink);
0b9536c9 VK	267
5bb629c5 FB	268	void led_trigger_blink_oneshot(struct led_trigger *trig,
	269	unsigned long *delay_on,
	270	unsigned long *delay_off,
	271	int invert)
	272	{
	273	led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);
	274	}
	275	EXPORT_SYMBOL_GPL(led_trigger_blink_oneshot);
	276
4d404fd5 NM	277	void led_trigger_register_simple(const char name, struct led_trigger *tp)
4d404fd5 NM	278	{
eb202621	279	struct led_trigger *trig;
4d404fd5	280	int err;
c3bc9956	281
eb202621	282	trig = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
c3bc9956	283
eb202621 BW	284	if (trig) {
	285	trig->name = name;
	286	err = led_trigger_register(trig);
cba4c2ac	287	if (err < 0) {
eb202621 BW	288	kfree(trig);
eb202621 BW	289	trig = NULL;
4d404fd5 NM	290	printk(KERN_WARNING "LED trigger %s failed to register"
4d404fd5 NM	291	" (%d)\n", name, err);
cba4c2ac	292	}
4d404fd5 NM	293	} else
	294	printk(KERN_WARNING "LED trigger %s failed to register"
	295	" (no memory)\n", name);
	296
eb202621	297	*tp = trig;
4d404fd5	298	}
c3bc9956	299	EXPORT_SYMBOL_GPL(led_trigger_register_simple);
4d404fd5	300
eb202621	301	void led_trigger_unregister_simple(struct led_trigger *trig)
4d404fd5	302	{
eb202621 BW	303	if (trig)
	304	led_trigger_unregister(trig);
	305	kfree(trig);
4d404fd5	306	}
c3bc9956	307	EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
c3bc9956 RP	308
	309	MODULE_AUTHOR("Richard Purdie");
	310	MODULE_LICENSE("GPL");
	311	MODULE_DESCRIPTION("LED Triggers Core");