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

/*
 * LED Triggers Core
 *
 * Copyright 2005-2006 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 class_device *dev, const char *buf,
			size_t count)
{
	struct led_classdev *led_cdev = class_get_devdata(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 class_device *dev, char *buf)
{
	struct led_classdev *led_cdev = class_get_devdata(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	*
	4	* Copyright 2005-2006 Openedhand Ltd.
	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);
	30
	31	ssize_t led_trigger_store(struct class_device dev, const char buf,
	32	size_t count)
	33	{
	34	struct led_classdev *led_cdev = class_get_devdata(dev);
	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
	70	ssize_t led_trigger_show(struct class_device dev, char buf)
	71	{
	72	struct led_classdev *led_cdev = class_get_devdata(dev);
	73	struct led_trigger *trig;
	74	int len = 0;
	75
	76	read_lock(&triggers_list_lock);
	77	read_lock(&led_cdev->trigger_lock);
	78
	79	if (!led_cdev->trigger)
	80	len += sprintf(buf+len, "[none] ");
	81	else
	82	len += sprintf(buf+len, "none ");
	83
	84	list_for_each_entry(trig, &trigger_list, next_trig) {
	85	if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
	86	trig->name))
	87	len += sprintf(buf+len, "[%s] ", trig->name);
	88	else
	89	len += sprintf(buf+len, "%s ", trig->name);
	90	}
	91	read_unlock(&led_cdev->trigger_lock);
	92	read_unlock(&triggers_list_lock);
93
94	len += sprintf(len+buf, "\n");
95	return len;
96	}
97
98	void led_trigger_event(struct led_trigger *trigger,
99	enum led_brightness brightness)
100	{
101	struct list_head *entry;
102
103	if (!trigger)
104	return;
105
106	read_lock(&trigger->leddev_list_lock);
107	list_for_each(entry, &trigger->led_cdevs) {
108	struct led_classdev *led_cdev;
109
110	led_cdev = list_entry(entry, struct led_classdev, trig_list);
111	led_set_brightness(led_cdev, brightness);
112	}
113	read_unlock(&trigger->leddev_list_lock);
114	}
115
116	/* Caller must ensure led_cdev->trigger_lock held */
117	void led_trigger_set(struct led_classdev led_cdev, struct led_trigger trigger)
118	{
119	unsigned long flags;
120
121	/* Remove any existing trigger */
122	if (led_cdev->trigger) {
123	write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
124	list_del(&led_cdev->trig_list);
125	write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock, flags);
126	if (led_cdev->trigger->deactivate)
127	led_cdev->trigger->deactivate(led_cdev);
e3e5fc91	128	led_set_brightness(led_cdev, LED_OFF);
c3bc9956 RP	129	}
	130	if (trigger) {
	131	write_lock_irqsave(&trigger->leddev_list_lock, flags);
	132	list_add_tail(&led_cdev->trig_list, &trigger->led_cdevs);
	133	write_unlock_irqrestore(&trigger->leddev_list_lock, flags);
	134	if (trigger->activate)
	135	trigger->activate(led_cdev);
	136	}
	137	led_cdev->trigger = trigger;
	138	}
	139
	140	void led_trigger_set_default(struct led_classdev *led_cdev)
	141	{
	142	struct led_trigger *trig;
	143
	144	if (!led_cdev->default_trigger)
	145	return;
	146
	147	read_lock(&triggers_list_lock);
	148	write_lock(&led_cdev->trigger_lock);
	149	list_for_each_entry(trig, &trigger_list, next_trig) {
	150	if (!strcmp(led_cdev->default_trigger, trig->name))
	151	led_trigger_set(led_cdev, trig);
	152	}
	153	write_unlock(&led_cdev->trigger_lock);
	154	read_unlock(&triggers_list_lock);
	155	}
	156
	157	int led_trigger_register(struct led_trigger *trigger)
	158	{
	159	struct led_classdev *led_cdev;
	160
	161	rwlock_init(&trigger->leddev_list_lock);
	162	INIT_LIST_HEAD(&trigger->led_cdevs);
	163
	164	/* Add to the list of led triggers */
	165	write_lock(&triggers_list_lock);
	166	list_add_tail(&trigger->next_trig, &trigger_list);
	167	write_unlock(&triggers_list_lock);
	168
	169	/* Register with any LEDs that have this as a default trigger */
	170	read_lock(&leds_list_lock);
	171	list_for_each_entry(led_cdev, &leds_list, node) {
	172	write_lock(&led_cdev->trigger_lock);
	173	if (!led_cdev->trigger && led_cdev->default_trigger &&
	174	!strcmp(led_cdev->default_trigger, trigger->name))
	175	led_trigger_set(led_cdev, trigger);
	176	write_unlock(&led_cdev->trigger_lock);
	177	}
	178	read_unlock(&leds_list_lock);
	179
	180	return 0;
	181	}
	182
	183	void led_trigger_register_simple(const char name, struct led_trigger *tp)
	184	{
	185	struct led_trigger *trigger;
e3986f63	186	int err;
c3bc9956 RP	187
	188	trigger = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
	189
	190	if (trigger) {
	191	trigger->name = name;
e3986f63 RP	192	err = led_trigger_register(trigger);
	193	if (err < 0)
	194	printk(KERN_WARNING "LED trigger %s failed to register"
	195	" (%d)\n", name, err);
	196	} else
	197	printk(KERN_WARNING "LED trigger %s failed to register"
	198	" (no memory)\n", name);
	199
c3bc9956 RP	200	*tp = trigger;
	201	}
	202
	203	void led_trigger_unregister(struct led_trigger *trigger)
	204	{
	205	struct led_classdev *led_cdev;
	206
	207	/* Remove from the list of led triggers */
	208	write_lock(&triggers_list_lock);
	209	list_del(&trigger->next_trig);
	210	write_unlock(&triggers_list_lock);
	211
	212	/* Remove anyone actively using this trigger */
	213	read_lock(&leds_list_lock);
	214	list_for_each_entry(led_cdev, &leds_list, node) {
	215	write_lock(&led_cdev->trigger_lock);
	216	if (led_cdev->trigger == trigger)
	217	led_trigger_set(led_cdev, NULL);
	218	write_unlock(&led_cdev->trigger_lock);
	219	}
	220	read_unlock(&leds_list_lock);
	221	}
	222
	223	void led_trigger_unregister_simple(struct led_trigger *trigger)
	224	{
3593a6d6 RP	225	if (trigger)
3593a6d6 RP	226	led_trigger_unregister(trigger);
c3bc9956 RP	227	kfree(trigger);
	228	}
	229
	230	/* Used by LED Class */
	231	EXPORT_SYMBOL_GPL(led_trigger_set);
	232	EXPORT_SYMBOL_GPL(led_trigger_set_default);
	233	EXPORT_SYMBOL_GPL(led_trigger_show);
	234	EXPORT_SYMBOL_GPL(led_trigger_store);
	235
	236	/* LED Trigger Interface */
	237	EXPORT_SYMBOL_GPL(led_trigger_register);
	238	EXPORT_SYMBOL_GPL(led_trigger_unregister);
	239
	240	/* Simple LED Tigger Interface */
	241	EXPORT_SYMBOL_GPL(led_trigger_register_simple);
	242	EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
	243	EXPORT_SYMBOL_GPL(led_trigger_event);
	244
	245	MODULE_AUTHOR("Richard Purdie");
	246	MODULE_LICENSE("GPL");
	247	MODULE_DESCRIPTION("LED Triggers Core");