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/*
* 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 "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_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);
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");
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