[linux-2.6-block.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/config.h>
#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 rwlock_t triggers_list_lock = RW_LOCK_UNLOCKED;
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);
	}
	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;

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

	if (trigger) {
		trigger->name = name;
		led_trigger_register(trigger);
	}
	*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)
{
	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
	14	#include <linux/config.h>
	15	#include <linux/module.h>
	16	#include <linux/kernel.h>
	17	#include <linux/init.h>
	18	#include <linux/list.h>
	19	#include <linux/spinlock.h>
	20	#include <linux/device.h>
	21	#include <linux/sysdev.h>
	22	#include <linux/timer.h>
	23	#include <linux/leds.h>
	24	#include "leds.h"
	25
	26	/*
	27	* Nests outside led_cdev->trigger_lock
	28	*/
	29	static rwlock_t triggers_list_lock = RW_LOCK_UNLOCKED;
	30	static LIST_HEAD(trigger_list);
	31
	32	ssize_t led_trigger_store(struct class_device dev, const char buf,
	33	size_t count)
	34	{
	35	struct led_classdev *led_cdev = class_get_devdata(dev);
	36	char trigger_name[TRIG_NAME_MAX];
	37	struct led_trigger *trig;
	38	size_t len;
	39
	40	trigger_name[sizeof(trigger_name) - 1] = '\0';
	41	strncpy(trigger_name, buf, sizeof(trigger_name) - 1);
	42	len = strlen(trigger_name);
	43
	44	if (len && trigger_name[len - 1] == '\n')
	45	trigger_name[len - 1] = '\0';
	46
	47	if (!strcmp(trigger_name, "none")) {
	48	write_lock(&led_cdev->trigger_lock);
	49	led_trigger_set(led_cdev, NULL);
	50	write_unlock(&led_cdev->trigger_lock);
	51	return count;
	52	}
	53
	54	read_lock(&triggers_list_lock);
	55	list_for_each_entry(trig, &trigger_list, next_trig) {
	56	if (!strcmp(trigger_name, trig->name)) {
	57	write_lock(&led_cdev->trigger_lock);
	58	led_trigger_set(led_cdev, trig);
	59	write_unlock(&led_cdev->trigger_lock);
	60
	61	read_unlock(&triggers_list_lock);
	62	return count;
	63	}
	64	}
65	read_unlock(&triggers_list_lock);
66
67	return -EINVAL;
68	}
69
70
71	ssize_t led_trigger_show(struct class_device dev, char buf)
72	{
73	struct led_classdev *led_cdev = class_get_devdata(dev);
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);
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;
186
187	trigger = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
188
189	if (trigger) {
190	trigger->name = name;
191	led_trigger_register(trigger);
192	}
193	*tp = trigger;
194	}
195
196	void led_trigger_unregister(struct led_trigger *trigger)
197	{
198	struct led_classdev *led_cdev;
199
200	/* Remove from the list of led triggers */
201	write_lock(&triggers_list_lock);
202	list_del(&trigger->next_trig);
203	write_unlock(&triggers_list_lock);
204
205	/* Remove anyone actively using this trigger */
206	read_lock(&leds_list_lock);
207	list_for_each_entry(led_cdev, &leds_list, node) {
208	write_lock(&led_cdev->trigger_lock);
209	if (led_cdev->trigger == trigger)
210	led_trigger_set(led_cdev, NULL);
211	write_unlock(&led_cdev->trigger_lock);
212	}
213	read_unlock(&leds_list_lock);
214	}
215
216	void led_trigger_unregister_simple(struct led_trigger *trigger)
217	{
218	led_trigger_unregister(trigger);
219	kfree(trigger);
220	}
221
222	/* Used by LED Class */
223	EXPORT_SYMBOL_GPL(led_trigger_set);
224	EXPORT_SYMBOL_GPL(led_trigger_set_default);
225	EXPORT_SYMBOL_GPL(led_trigger_show);
226	EXPORT_SYMBOL_GPL(led_trigger_store);
227
228	/* LED Trigger Interface */
229	EXPORT_SYMBOL_GPL(led_trigger_register);
230	EXPORT_SYMBOL_GPL(led_trigger_unregister);
231
232	/* Simple LED Tigger Interface */
233	EXPORT_SYMBOL_GPL(led_trigger_register_simple);
234	EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
235	EXPORT_SYMBOL_GPL(led_trigger_event);
236
237	MODULE_AUTHOR("Richard Purdie");
238	MODULE_LICENSE("GPL");
239	MODULE_DESCRIPTION("LED Triggers Core");