forked from luck/tmp_suning_uos_patched
5bb629c504
Add two new functions, led_blink_set_oneshot and led_trigger_blink_oneshot, to be used by triggers for one-shot blink of led devices. This is implemented extending the existing software-blink code, and uses the same timer and handler function. The behavior of the code is to do a blink-on, blink-off sequence when the function is called, ignoring other calls until the sequence is completed so that the leds keep blinking at constant rate if the functions are called repeatedly. This is meant to be used by drivers which needs to trigger on sporadic event, but doesn't have clear busy/idle trigger points. After the blink sequence the led remains off. This behavior can be inverted setting the "invert" argument, which blink the led off, than on and leave the led on after the sequence. (bryan.wu@canonical.com: rebase to commit 'leds: don't disable blinking when writing the same value to delay_on or delay_off') Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com> Acked-by: Shuah Khan <shuahkhan@gmail.com> Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
310 lines
7.7 KiB
C
310 lines
7.7 KiB
C
/*
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* LED Triggers Core
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*
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* Copyright 2005-2007 Openedhand Ltd.
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*
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* Author: Richard Purdie <rpurdie@openedhand.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/list.h>
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#include <linux/spinlock.h>
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#include <linux/device.h>
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#include <linux/timer.h>
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#include <linux/rwsem.h>
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#include <linux/leds.h>
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#include <linux/slab.h>
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#include "leds.h"
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/*
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* Nests outside led_cdev->trigger_lock
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*/
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static DECLARE_RWSEM(triggers_list_lock);
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static LIST_HEAD(trigger_list);
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/* Used by LED Class */
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ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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char trigger_name[TRIG_NAME_MAX];
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struct led_trigger *trig;
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size_t len;
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trigger_name[sizeof(trigger_name) - 1] = '\0';
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strncpy(trigger_name, buf, sizeof(trigger_name) - 1);
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len = strlen(trigger_name);
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if (len && trigger_name[len - 1] == '\n')
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trigger_name[len - 1] = '\0';
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if (!strcmp(trigger_name, "none")) {
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led_trigger_remove(led_cdev);
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return count;
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}
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down_read(&triggers_list_lock);
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list_for_each_entry(trig, &trigger_list, next_trig) {
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if (!strcmp(trigger_name, trig->name)) {
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down_write(&led_cdev->trigger_lock);
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led_trigger_set(led_cdev, trig);
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up_write(&led_cdev->trigger_lock);
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up_read(&triggers_list_lock);
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return count;
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}
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}
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up_read(&triggers_list_lock);
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return -EINVAL;
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}
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EXPORT_SYMBOL_GPL(led_trigger_store);
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ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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struct led_trigger *trig;
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int len = 0;
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down_read(&triggers_list_lock);
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down_read(&led_cdev->trigger_lock);
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if (!led_cdev->trigger)
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len += sprintf(buf+len, "[none] ");
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else
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len += sprintf(buf+len, "none ");
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list_for_each_entry(trig, &trigger_list, next_trig) {
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if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
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trig->name))
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len += sprintf(buf+len, "[%s] ", trig->name);
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else
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len += sprintf(buf+len, "%s ", trig->name);
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}
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up_read(&led_cdev->trigger_lock);
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up_read(&triggers_list_lock);
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len += sprintf(len+buf, "\n");
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return len;
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}
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EXPORT_SYMBOL_GPL(led_trigger_show);
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/* Caller must ensure led_cdev->trigger_lock held */
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void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
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{
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unsigned long flags;
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/* Remove any existing trigger */
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if (led_cdev->trigger) {
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write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
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list_del(&led_cdev->trig_list);
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write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
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flags);
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if (led_cdev->trigger->deactivate)
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led_cdev->trigger->deactivate(led_cdev);
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led_cdev->trigger = NULL;
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led_brightness_set(led_cdev, LED_OFF);
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}
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if (trig) {
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write_lock_irqsave(&trig->leddev_list_lock, flags);
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list_add_tail(&led_cdev->trig_list, &trig->led_cdevs);
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write_unlock_irqrestore(&trig->leddev_list_lock, flags);
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led_cdev->trigger = trig;
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if (trig->activate)
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trig->activate(led_cdev);
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}
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}
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EXPORT_SYMBOL_GPL(led_trigger_set);
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void led_trigger_remove(struct led_classdev *led_cdev)
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{
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down_write(&led_cdev->trigger_lock);
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led_trigger_set(led_cdev, NULL);
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up_write(&led_cdev->trigger_lock);
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}
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EXPORT_SYMBOL_GPL(led_trigger_remove);
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void led_trigger_set_default(struct led_classdev *led_cdev)
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{
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struct led_trigger *trig;
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if (!led_cdev->default_trigger)
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return;
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down_read(&triggers_list_lock);
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down_write(&led_cdev->trigger_lock);
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list_for_each_entry(trig, &trigger_list, next_trig) {
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if (!strcmp(led_cdev->default_trigger, trig->name))
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led_trigger_set(led_cdev, trig);
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}
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up_write(&led_cdev->trigger_lock);
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up_read(&triggers_list_lock);
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}
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EXPORT_SYMBOL_GPL(led_trigger_set_default);
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/* LED Trigger Interface */
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int led_trigger_register(struct led_trigger *trig)
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{
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struct led_classdev *led_cdev;
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struct led_trigger *_trig;
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rwlock_init(&trig->leddev_list_lock);
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INIT_LIST_HEAD(&trig->led_cdevs);
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down_write(&triggers_list_lock);
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/* Make sure the trigger's name isn't already in use */
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list_for_each_entry(_trig, &trigger_list, next_trig) {
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if (!strcmp(_trig->name, trig->name)) {
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up_write(&triggers_list_lock);
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return -EEXIST;
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}
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}
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/* Add to the list of led triggers */
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list_add_tail(&trig->next_trig, &trigger_list);
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up_write(&triggers_list_lock);
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/* Register with any LEDs that have this as a default trigger */
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down_read(&leds_list_lock);
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list_for_each_entry(led_cdev, &leds_list, node) {
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down_write(&led_cdev->trigger_lock);
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if (!led_cdev->trigger && led_cdev->default_trigger &&
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!strcmp(led_cdev->default_trigger, trig->name))
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led_trigger_set(led_cdev, trig);
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up_write(&led_cdev->trigger_lock);
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}
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up_read(&leds_list_lock);
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return 0;
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}
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EXPORT_SYMBOL_GPL(led_trigger_register);
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void led_trigger_unregister(struct led_trigger *trig)
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{
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struct led_classdev *led_cdev;
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/* Remove from the list of led triggers */
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down_write(&triggers_list_lock);
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list_del(&trig->next_trig);
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up_write(&triggers_list_lock);
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/* Remove anyone actively using this trigger */
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down_read(&leds_list_lock);
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list_for_each_entry(led_cdev, &leds_list, node) {
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down_write(&led_cdev->trigger_lock);
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if (led_cdev->trigger == trig)
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led_trigger_set(led_cdev, NULL);
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up_write(&led_cdev->trigger_lock);
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}
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up_read(&leds_list_lock);
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}
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EXPORT_SYMBOL_GPL(led_trigger_unregister);
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/* Simple LED Tigger Interface */
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void led_trigger_event(struct led_trigger *trig,
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enum led_brightness brightness)
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{
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struct list_head *entry;
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if (!trig)
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return;
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read_lock(&trig->leddev_list_lock);
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list_for_each(entry, &trig->led_cdevs) {
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struct led_classdev *led_cdev;
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led_cdev = list_entry(entry, struct led_classdev, trig_list);
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led_set_brightness(led_cdev, brightness);
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}
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read_unlock(&trig->leddev_list_lock);
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}
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EXPORT_SYMBOL_GPL(led_trigger_event);
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void led_trigger_blink_setup(struct led_trigger *trig,
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unsigned long *delay_on,
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unsigned long *delay_off,
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int oneshot,
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int invert)
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{
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struct list_head *entry;
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if (!trig)
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return;
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read_lock(&trig->leddev_list_lock);
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list_for_each(entry, &trig->led_cdevs) {
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struct led_classdev *led_cdev;
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led_cdev = list_entry(entry, struct led_classdev, trig_list);
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if (oneshot)
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led_blink_set_oneshot(led_cdev, delay_on, delay_off,
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invert);
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else
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led_blink_set(led_cdev, delay_on, delay_off);
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}
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read_unlock(&trig->leddev_list_lock);
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}
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void led_trigger_blink(struct led_trigger *trig,
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unsigned long *delay_on,
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unsigned long *delay_off)
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{
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led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
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}
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EXPORT_SYMBOL_GPL(led_trigger_blink);
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void led_trigger_blink_oneshot(struct led_trigger *trig,
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unsigned long *delay_on,
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unsigned long *delay_off,
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int invert)
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{
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led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);
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}
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EXPORT_SYMBOL_GPL(led_trigger_blink_oneshot);
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void led_trigger_register_simple(const char *name, struct led_trigger **tp)
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{
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struct led_trigger *trig;
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int err;
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trig = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
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if (trig) {
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trig->name = name;
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err = led_trigger_register(trig);
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if (err < 0) {
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kfree(trig);
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trig = NULL;
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printk(KERN_WARNING "LED trigger %s failed to register"
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" (%d)\n", name, err);
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}
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} else
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printk(KERN_WARNING "LED trigger %s failed to register"
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" (no memory)\n", name);
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*tp = trig;
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}
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EXPORT_SYMBOL_GPL(led_trigger_register_simple);
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void led_trigger_unregister_simple(struct led_trigger *trig)
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{
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if (trig)
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led_trigger_unregister(trig);
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kfree(trig);
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}
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EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
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MODULE_AUTHOR("Richard Purdie");
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("LED Triggers Core");
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