[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/sysdev.h>
#include <linux/timer.h>
#include <linux/leds.h>
#include "leds.h"

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

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")) {
		write_lock(&led_cdev->trigger_lock);
		led_trigger_set(led_cdev, NULL);
		write_unlock(&led_cdev->trigger_lock);
		return count;
	}

	read_lock(&triggers_list_lock);
	list_for_each_entry(trig, &trigger_list, next_trig) {
		if (!strcmp(trigger_name, trig->name)) {
			write_lock(&led_cdev->trigger_lock);
			led_trigger_set(led_cdev, trig);
			write_unlock(&led_cdev->trigger_lock);

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

	return -EINVAL;
}


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;

	read_lock(&triggers_list_lock);
	read_lock(&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);
	}
	read_unlock(&led_cdev->trigger_lock);
	read_unlock(&triggers_list_lock);

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

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

	if (!trigger)
		return;

	read_lock(&trigger->leddev_list_lock);
	list_for_each(entry, &trigger->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(&trigger->leddev_list_lock);
}

/* Caller must ensure led_cdev->trigger_lock held */
void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger)
{
	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);
		if (led_cdev->trigger->deactivate)
			led_cdev->trigger->deactivate(led_cdev);
		led_set_brightness(led_cdev, LED_OFF);
	}
	if (trigger) {
		write_lock_irqsave(&trigger->leddev_list_lock, flags);
		list_add_tail(&led_cdev->trig_list, &trigger->led_cdevs);
		write_unlock_irqrestore(&trigger->leddev_list_lock, flags);
		if (trigger->activate)
			trigger->activate(led_cdev);
	}
	led_cdev->trigger = trigger;
}

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

	if (!led_cdev->default_trigger)
		return;

	read_lock(&triggers_list_lock);
	write_lock(&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);
	}
	write_unlock(&led_cdev->trigger_lock);
	read_unlock(&triggers_list_lock);
}

int led_trigger_register(struct led_trigger *trigger)
{
	struct led_classdev *led_cdev;

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

	/* Add to the list of led triggers */
	write_lock(&triggers_list_lock);
	list_add_tail(&trigger->next_trig, &trigger_list);
	write_unlock(&triggers_list_lock);

	/* Register with any LEDs that have this as a default trigger */
	read_lock(&leds_list_lock);
	list_for_each_entry(led_cdev, &leds_list, node) {
		write_lock(&led_cdev->trigger_lock);
		if (!led_cdev->trigger && led_cdev->default_trigger &&
			    !strcmp(led_cdev->default_trigger, trigger->name))
			led_trigger_set(led_cdev, trigger);
		write_unlock(&led_cdev->trigger_lock);
	}
	read_unlock(&leds_list_lock);

	return 0;
}

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

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

	if (trigger) {
		trigger->name = name;
		err = led_trigger_register(trigger);
		if (err < 0)
			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 = trigger;
}

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

	/* Remove from the list of led triggers */
	write_lock(&triggers_list_lock);
	list_del(&trigger->next_trig);
	write_unlock(&triggers_list_lock);

	/* Remove anyone actively using this trigger */
	read_lock(&leds_list_lock);
	list_for_each_entry(led_cdev, &leds_list, node) {
		write_lock(&led_cdev->trigger_lock);
		if (led_cdev->trigger == trigger)
			led_trigger_set(led_cdev, NULL);
		write_unlock(&led_cdev->trigger_lock);
	}
	read_unlock(&leds_list_lock);
}

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

/* Used by LED Class */
EXPORT_SYMBOL_GPL(led_trigger_set);
EXPORT_SYMBOL_GPL(led_trigger_set_default);
EXPORT_SYMBOL_GPL(led_trigger_show);
EXPORT_SYMBOL_GPL(led_trigger_store);

/* LED Trigger Interface */
EXPORT_SYMBOL_GPL(led_trigger_register);
EXPORT_SYMBOL_GPL(led_trigger_unregister);

/* Simple LED Tigger Interface */
EXPORT_SYMBOL_GPL(led_trigger_register_simple);
EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
EXPORT_SYMBOL_GPL(led_trigger_event);

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>
	20	#include <linux/sysdev.h>
	21	#include <linux/timer.h>
	22	#include <linux/leds.h>
	23	#include "leds.h"
	24
	25	/*
	26	* Nests outside led_cdev->trigger_lock
	27	*/
34af946a	28	static DEFINE_RWLOCK(triggers_list_lock);
c3bc9956 RP	29	static LIST_HEAD(trigger_list);
c3bc9956 RP	30
f8a7c6fe RP	31	ssize_t led_trigger_store(struct device dev, struct device_attribute attr,
f8a7c6fe RP	32	const char *buf, size_t count)
c3bc9956	33	{
f8a7c6fe	34	struct led_classdev *led_cdev = dev_get_drvdata(dev);
c3bc9956 RP	35	char trigger_name[TRIG_NAME_MAX];
	36	struct led_trigger *trig;
	37	size_t len;
	38
	39	trigger_name[sizeof(trigger_name) - 1] = '\0';
	40	strncpy(trigger_name, buf, sizeof(trigger_name) - 1);
	41	len = strlen(trigger_name);
	42
	43	if (len && trigger_name[len - 1] == '\n')
	44	trigger_name[len - 1] = '\0';
	45
	46	if (!strcmp(trigger_name, "none")) {
	47	write_lock(&led_cdev->trigger_lock);
	48	led_trigger_set(led_cdev, NULL);
	49	write_unlock(&led_cdev->trigger_lock);
	50	return count;
	51	}
	52
	53	read_lock(&triggers_list_lock);
	54	list_for_each_entry(trig, &trigger_list, next_trig) {
	55	if (!strcmp(trigger_name, trig->name)) {
	56	write_lock(&led_cdev->trigger_lock);
	57	led_trigger_set(led_cdev, trig);
	58	write_unlock(&led_cdev->trigger_lock);
	59
	60	read_unlock(&triggers_list_lock);
	61	return count;
	62	}
	63	}
	64	read_unlock(&triggers_list_lock);
	65
	66	return -EINVAL;
	67	}
	68
	69
f8a7c6fe RP	70	ssize_t led_trigger_show(struct device dev, struct device_attribute attr,
f8a7c6fe RP	71	char *buf)
c3bc9956	72	{
f8a7c6fe	73	struct led_classdev *led_cdev = dev_get_drvdata(dev);
c3bc9956 RP	74	struct led_trigger *trig;
	75	int len = 0;
	76
	77	read_lock(&triggers_list_lock);
	78	read_lock(&led_cdev->trigger_lock);
	79
	80	if (!led_cdev->trigger)
	81	len += sprintf(buf+len, "[none] ");
	82	else
	83	len += sprintf(buf+len, "none ");
	84
	85	list_for_each_entry(trig, &trigger_list, next_trig) {
	86	if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
	87	trig->name))
	88	len += sprintf(buf+len, "[%s] ", trig->name);
	89	else
	90	len += sprintf(buf+len, "%s ", trig->name);
	91	}
	92	read_unlock(&led_cdev->trigger_lock);
	93	read_unlock(&triggers_list_lock);
	94
	95	len += sprintf(len+buf, "\n");
	96	return len;
	97	}
	98
	99	void led_trigger_event(struct led_trigger *trigger,
	100	enum led_brightness brightness)
	101	{
	102	struct list_head *entry;
	103
	104	if (!trigger)
	105	return;
	106
	107	read_lock(&trigger->leddev_list_lock);
	108	list_for_each(entry, &trigger->led_cdevs) {
	109	struct led_classdev *led_cdev;
	110
	111	led_cdev = list_entry(entry, struct led_classdev, trig_list);
	112	led_set_brightness(led_cdev, brightness);
	113	}
	114	read_unlock(&trigger->leddev_list_lock);
	115	}
	116
	117	/* Caller must ensure led_cdev->trigger_lock held */
	118	void led_trigger_set(struct led_classdev led_cdev, struct led_trigger trigger)
	119	{
	120	unsigned long flags;
	121
	122	/* Remove any existing trigger */
	123	if (led_cdev->trigger) {
	124	write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
	125	list_del(&led_cdev->trig_list);
	126	write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock, flags);
	127	if (led_cdev->trigger->deactivate)
	128	led_cdev->trigger->deactivate(led_cdev);
e3e5fc91	129	led_set_brightness(led_cdev, LED_OFF);
c3bc9956 RP	130	}
	131	if (trigger) {
	132	write_lock_irqsave(&trigger->leddev_list_lock, flags);
	133	list_add_tail(&led_cdev->trig_list, &trigger->led_cdevs);
	134	write_unlock_irqrestore(&trigger->leddev_list_lock, flags);
	135	if (trigger->activate)
	136	trigger->activate(led_cdev);
	137	}
	138	led_cdev->trigger = trigger;
	139	}
	140
	141	void led_trigger_set_default(struct led_classdev *led_cdev)
	142	{
	143	struct led_trigger *trig;
	144
	145	if (!led_cdev->default_trigger)
	146	return;
	147
	148	read_lock(&triggers_list_lock);
	149	write_lock(&led_cdev->trigger_lock);
	150	list_for_each_entry(trig, &trigger_list, next_trig) {
	151	if (!strcmp(led_cdev->default_trigger, trig->name))
	152	led_trigger_set(led_cdev, trig);
	153	}
	154	write_unlock(&led_cdev->trigger_lock);
	155	read_unlock(&triggers_list_lock);
	156	}
	157
	158	int led_trigger_register(struct led_trigger *trigger)
	159	{
	160	struct led_classdev *led_cdev;
	161
	162	rwlock_init(&trigger->leddev_list_lock);
	163	INIT_LIST_HEAD(&trigger->led_cdevs);
	164
	165	/* Add to the list of led triggers */
	166	write_lock(&triggers_list_lock);
	167	list_add_tail(&trigger->next_trig, &trigger_list);
	168	write_unlock(&triggers_list_lock);
	169
	170	/* Register with any LEDs that have this as a default trigger */
	171	read_lock(&leds_list_lock);
	172	list_for_each_entry(led_cdev, &leds_list, node) {
	173	write_lock(&led_cdev->trigger_lock);
	174	if (!led_cdev->trigger && led_cdev->default_trigger &&
	175	!strcmp(led_cdev->default_trigger, trigger->name))
	176	led_trigger_set(led_cdev, trigger);
	177	write_unlock(&led_cdev->trigger_lock);
	178	}
	179	read_unlock(&leds_list_lock);
	180
	181	return 0;
	182	}
	183
	184	void led_trigger_register_simple(const char name, struct led_trigger *tp)
	185	{
	186	struct led_trigger *trigger;
e3986f63	187	int err;
c3bc9956 RP	188
	189	trigger = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
	190
	191	if (trigger) {
	192	trigger->name = name;
e3986f63 RP	193	err = led_trigger_register(trigger);
	194	if (err < 0)
	195	printk(KERN_WARNING "LED trigger %s failed to register"
	196	" (%d)\n", name, err);
	197	} else
	198	printk(KERN_WARNING "LED trigger %s failed to register"
	199	" (no memory)\n", name);
	200
c3bc9956 RP	201	*tp = trigger;
	202	}
	203
	204	void led_trigger_unregister(struct led_trigger *trigger)
	205	{
	206	struct led_classdev *led_cdev;
	207
	208	/* Remove from the list of led triggers */
	209	write_lock(&triggers_list_lock);
	210	list_del(&trigger->next_trig);
	211	write_unlock(&triggers_list_lock);
	212
	213	/* Remove anyone actively using this trigger */
	214	read_lock(&leds_list_lock);
	215	list_for_each_entry(led_cdev, &leds_list, node) {
	216	write_lock(&led_cdev->trigger_lock);
	217	if (led_cdev->trigger == trigger)
	218	led_trigger_set(led_cdev, NULL);
	219	write_unlock(&led_cdev->trigger_lock);
	220	}
	221	read_unlock(&leds_list_lock);
	222	}
	223
	224	void led_trigger_unregister_simple(struct led_trigger *trigger)
	225	{
3593a6d6 RP	226	if (trigger)
3593a6d6 RP	227	led_trigger_unregister(trigger);
c3bc9956 RP	228	kfree(trigger);
	229	}
	230
	231	/* Used by LED Class */
	232	EXPORT_SYMBOL_GPL(led_trigger_set);
	233	EXPORT_SYMBOL_GPL(led_trigger_set_default);
	234	EXPORT_SYMBOL_GPL(led_trigger_show);
	235	EXPORT_SYMBOL_GPL(led_trigger_store);
	236
	237	/* LED Trigger Interface */
	238	EXPORT_SYMBOL_GPL(led_trigger_register);
	239	EXPORT_SYMBOL_GPL(led_trigger_unregister);
	240
	241	/* Simple LED Tigger Interface */
	242	EXPORT_SYMBOL_GPL(led_trigger_register_simple);
	243	EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
	244	EXPORT_SYMBOL_GPL(led_trigger_event);
	245
	246	MODULE_AUTHOR("Richard Purdie");
	247	MODULE_LICENSE("GPL");
	248	MODULE_DESCRIPTION("LED Triggers Core");