[net-next-2.6.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/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 *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_cdev->trigger = NULL;
		led_brightness_set(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);
		led_cdev->trigger = trigger;
		if (trigger->activate)
			trigger->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 *trigger)
{
	struct led_classdev *led_cdev;
	struct led_trigger *trig;

	rwlock_init(&trigger->leddev_list_lock);
	INIT_LIST_HEAD(&trigger->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, trigger->name)) {
			up_write(&triggers_list_lock);
			return -EEXIST;
		}
	}
	/* Add to the list of led triggers */
	list_add_tail(&trigger->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, trigger->name))
			led_trigger_set(led_cdev, trigger);
		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 *trigger)
{
	struct led_classdev *led_cdev;

	/* Remove from the list of led triggers */
	down_write(&triggers_list_lock);
	list_del(&trigger->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 == trigger)
			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 *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);
}
EXPORT_SYMBOL_GPL(led_trigger_event);

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;
}
EXPORT_SYMBOL_GPL(led_trigger_register_simple);

void led_trigger_unregister_simple(struct led_trigger *trigger)
{
	if (trigger)
		led_trigger_unregister(trigger);
	kfree(trigger);
}
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>
	20	#include <linux/sysdev.h>
	21	#include <linux/timer.h>
dc47206e	22	#include <linux/rwsem.h>
c3bc9956	23	#include <linux/leds.h>
5a0e3ad6	24	#include <linux/slab.h>
c3bc9956 RP	25	#include "leds.h"
	26
	27	/*
	28	* Nests outside led_cdev->trigger_lock
	29	*/
dc47206e	30	static DECLARE_RWSEM(triggers_list_lock);
c3bc9956 RP	31	static LIST_HEAD(trigger_list);
c3bc9956 RP	32
4d404fd5 NM	33	/* Used by LED Class */
4d404fd5 NM	34
f8a7c6fe RP	35	ssize_t led_trigger_store(struct device dev, struct device_attribute attr,
f8a7c6fe RP	36	const char *buf, size_t count)
c3bc9956	37	{
f8a7c6fe	38	struct led_classdev *led_cdev = dev_get_drvdata(dev);
c3bc9956 RP	39	char trigger_name[TRIG_NAME_MAX];
	40	struct led_trigger *trig;
	41	size_t len;
	42
	43	trigger_name[sizeof(trigger_name) - 1] = '\0';
	44	strncpy(trigger_name, buf, sizeof(trigger_name) - 1);
	45	len = strlen(trigger_name);
	46
	47	if (len && trigger_name[len - 1] == '\n')
	48	trigger_name[len - 1] = '\0';
	49
	50	if (!strcmp(trigger_name, "none")) {
0013b23d	51	led_trigger_remove(led_cdev);
c3bc9956 RP	52	return count;
	53	}
	54
dc47206e	55	down_read(&triggers_list_lock);
c3bc9956 RP	56	list_for_each_entry(trig, &trigger_list, next_trig) {
c3bc9956 RP	57	if (!strcmp(trigger_name, trig->name)) {
dc47206e	58	down_write(&led_cdev->trigger_lock);
c3bc9956	59	led_trigger_set(led_cdev, trig);
dc47206e	60	up_write(&led_cdev->trigger_lock);
c3bc9956	61
dc47206e	62	up_read(&triggers_list_lock);
c3bc9956 RP	63	return count;
	64	}
	65	}
dc47206e	66	up_read(&triggers_list_lock);
c3bc9956 RP	67
	68	return -EINVAL;
	69	}
4d404fd5	70	EXPORT_SYMBOL_GPL(led_trigger_store);
c3bc9956	71
f8a7c6fe RP	72	ssize_t led_trigger_show(struct device dev, struct device_attribute attr,
f8a7c6fe RP	73	char *buf)
c3bc9956	74	{
f8a7c6fe	75	struct led_classdev *led_cdev = dev_get_drvdata(dev);
c3bc9956 RP	76	struct led_trigger *trig;
	77	int len = 0;
	78
dc47206e RP	79	down_read(&triggers_list_lock);
dc47206e RP	80	down_read(&led_cdev->trigger_lock);
c3bc9956 RP	81
	82	if (!led_cdev->trigger)
	83	len += sprintf(buf+len, "[none] ");
	84	else
	85	len += sprintf(buf+len, "none ");
	86
	87	list_for_each_entry(trig, &trigger_list, next_trig) {
	88	if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
	89	trig->name))
	90	len += sprintf(buf+len, "[%s] ", trig->name);
	91	else
	92	len += sprintf(buf+len, "%s ", trig->name);
	93	}
dc47206e RP	94	up_read(&led_cdev->trigger_lock);
dc47206e RP	95	up_read(&triggers_list_lock);
c3bc9956 RP	96
	97	len += sprintf(len+buf, "\n");
	98	return len;
	99	}
4d404fd5	100	EXPORT_SYMBOL_GPL(led_trigger_show);
c3bc9956 RP	101
	102	/* Caller must ensure led_cdev->trigger_lock held */
	103	void led_trigger_set(struct led_classdev led_cdev, struct led_trigger trigger)
	104	{
	105	unsigned long flags;
	106
	107	/* Remove any existing trigger */
	108	if (led_cdev->trigger) {
	109	write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
	110	list_del(&led_cdev->trig_list);
4d404fd5 NM	111	write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
4d404fd5 NM	112	flags);
c3bc9956 RP	113	if (led_cdev->trigger->deactivate)
c3bc9956 RP	114	led_cdev->trigger->deactivate(led_cdev);
fe3025b5	115	led_cdev->trigger = NULL;
5ada28bf	116	led_brightness_set(led_cdev, LED_OFF);
c3bc9956 RP	117	}
	118	if (trigger) {
	119	write_lock_irqsave(&trigger->leddev_list_lock, flags);
	120	list_add_tail(&led_cdev->trig_list, &trigger->led_cdevs);
	121	write_unlock_irqrestore(&trigger->leddev_list_lock, flags);
fe3025b5	122	led_cdev->trigger = trigger;
c3bc9956 RP	123	if (trigger->activate)
	124	trigger->activate(led_cdev);
	125	}
c3bc9956	126	}
4d404fd5	127	EXPORT_SYMBOL_GPL(led_trigger_set);
c3bc9956	128
0013b23d NM	129	void led_trigger_remove(struct led_classdev *led_cdev)
	130	{
	131	down_write(&led_cdev->trigger_lock);
	132	led_trigger_set(led_cdev, NULL);
	133	up_write(&led_cdev->trigger_lock);
	134	}
4d404fd5	135	EXPORT_SYMBOL_GPL(led_trigger_remove);
0013b23d	136
c3bc9956 RP	137	void led_trigger_set_default(struct led_classdev *led_cdev)
	138	{
	139	struct led_trigger *trig;
	140
	141	if (!led_cdev->default_trigger)
	142	return;
	143
dc47206e RP	144	down_read(&triggers_list_lock);
dc47206e RP	145	down_write(&led_cdev->trigger_lock);
c3bc9956 RP	146	list_for_each_entry(trig, &trigger_list, next_trig) {
	147	if (!strcmp(led_cdev->default_trigger, trig->name))
	148	led_trigger_set(led_cdev, trig);
	149	}
dc47206e RP	150	up_write(&led_cdev->trigger_lock);
dc47206e RP	151	up_read(&triggers_list_lock);
c3bc9956	152	}
4d404fd5 NM	153	EXPORT_SYMBOL_GPL(led_trigger_set_default);
	154
	155	/* LED Trigger Interface */
c3bc9956 RP	156
	157	int led_trigger_register(struct led_trigger *trigger)
	158	{
	159	struct led_classdev *led_cdev;
700c6ea2	160	struct led_trigger *trig;
c3bc9956 RP	161
	162	rwlock_init(&trigger->leddev_list_lock);
	163	INIT_LIST_HEAD(&trigger->led_cdevs);
	164
dc47206e	165	down_write(&triggers_list_lock);
700c6ea2 AN	166	/* Make sure the trigger's name isn't already in use */
	167	list_for_each_entry(trig, &trigger_list, next_trig) {
	168	if (!strcmp(trig->name, trigger->name)) {
	169	up_write(&triggers_list_lock);
	170	return -EEXIST;
	171	}
	172	}
	173	/* Add to the list of led triggers */
c3bc9956	174	list_add_tail(&trigger->next_trig, &trigger_list);
dc47206e	175	up_write(&triggers_list_lock);
c3bc9956 RP	176
c3bc9956 RP	177	/* Register with any LEDs that have this as a default trigger */
72f8da32	178	down_read(&leds_list_lock);
c3bc9956	179	list_for_each_entry(led_cdev, &leds_list, node) {
dc47206e	180	down_write(&led_cdev->trigger_lock);
c3bc9956 RP	181	if (!led_cdev->trigger && led_cdev->default_trigger &&
	182	!strcmp(led_cdev->default_trigger, trigger->name))
	183	led_trigger_set(led_cdev, trigger);
dc47206e	184	up_write(&led_cdev->trigger_lock);
c3bc9956	185	}
72f8da32	186	up_read(&leds_list_lock);
c3bc9956 RP	187
	188	return 0;
	189	}
4d404fd5	190	EXPORT_SYMBOL_GPL(led_trigger_register);
c3bc9956 RP	191
	192	void led_trigger_unregister(struct led_trigger *trigger)
	193	{
	194	struct led_classdev *led_cdev;
	195
	196	/* Remove from the list of led triggers */
dc47206e	197	down_write(&triggers_list_lock);
c3bc9956	198	list_del(&trigger->next_trig);
dc47206e	199	up_write(&triggers_list_lock);
c3bc9956 RP	200
c3bc9956 RP	201	/* Remove anyone actively using this trigger */
72f8da32	202	down_read(&leds_list_lock);
c3bc9956	203	list_for_each_entry(led_cdev, &leds_list, node) {
dc47206e	204	down_write(&led_cdev->trigger_lock);
c3bc9956 RP	205	if (led_cdev->trigger == trigger)
c3bc9956 RP	206	led_trigger_set(led_cdev, NULL);
dc47206e	207	up_write(&led_cdev->trigger_lock);
c3bc9956	208	}
72f8da32	209	up_read(&leds_list_lock);
c3bc9956	210	}
4d404fd5	211	EXPORT_SYMBOL_GPL(led_trigger_unregister);
c3bc9956	212
4d404fd5 NM	213	/* Simple LED Tigger Interface */
	214
	215	void led_trigger_event(struct led_trigger *trigger,
	216	enum led_brightness brightness)
c3bc9956	217	{
4d404fd5 NM	218	struct list_head *entry;
	219
	220	if (!trigger)
	221	return;
	222
	223	read_lock(&trigger->leddev_list_lock);
	224	list_for_each(entry, &trigger->led_cdevs) {
	225	struct led_classdev *led_cdev;
	226
	227	led_cdev = list_entry(entry, struct led_classdev, trig_list);
	228	led_set_brightness(led_cdev, brightness);
	229	}
	230	read_unlock(&trigger->leddev_list_lock);
c3bc9956	231	}
4d404fd5	232	EXPORT_SYMBOL_GPL(led_trigger_event);
c3bc9956	233
4d404fd5 NM	234	void led_trigger_register_simple(const char name, struct led_trigger *tp)
	235	{
	236	struct led_trigger *trigger;
	237	int err;
c3bc9956	238
4d404fd5	239	trigger = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
c3bc9956	240
4d404fd5 NM	241	if (trigger) {
	242	trigger->name = name;
	243	err = led_trigger_register(trigger);
	244	if (err < 0)
	245	printk(KERN_WARNING "LED trigger %s failed to register"
	246	" (%d)\n", name, err);
	247	} else
	248	printk(KERN_WARNING "LED trigger %s failed to register"
	249	" (no memory)\n", name);
	250
	251	*tp = trigger;
	252	}
c3bc9956	253	EXPORT_SYMBOL_GPL(led_trigger_register_simple);
4d404fd5 NM	254
	255	void led_trigger_unregister_simple(struct led_trigger *trigger)
	256	{
	257	if (trigger)
	258	led_trigger_unregister(trigger);
	259	kfree(trigger);
	260	}
c3bc9956	261	EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
c3bc9956 RP	262
	263	MODULE_AUTHOR("Richard Purdie");
	264	MODULE_LICENSE("GPL");
	265	MODULE_DESCRIPTION("LED Triggers Core");