265 lines
6.5 KiB
C
265 lines
6.5 KiB
C
/*
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* LED Class Core
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*
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* Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
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* Copyright (C) 2005-2007 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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#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/err.h>
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#include <linux/ctype.h>
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#include <linux/leds.h>
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#include "leds.h"
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#define LED_BUFF_SIZE 50
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static struct class *leds_class;
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static void led_update_brightness(struct led_classdev *led_cdev)
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{
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if (led_cdev->brightness_get)
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led_cdev->brightness = led_cdev->brightness_get(led_cdev);
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}
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static ssize_t led_brightness_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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/* no lock needed for this */
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led_update_brightness(led_cdev);
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return snprintf(buf, LED_BUFF_SIZE, "%u\n", led_cdev->brightness);
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}
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static ssize_t led_brightness_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t size)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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ssize_t ret = -EINVAL;
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char *after;
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unsigned long state = simple_strtoul(buf, &after, 10);
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size_t count = after - buf;
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if (isspace(*after))
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count++;
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if (count == size) {
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ret = count;
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if (state == LED_OFF)
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led_trigger_remove(led_cdev);
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led_set_brightness(led_cdev, state);
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}
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return ret;
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}
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static ssize_t led_max_brightness_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t size)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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ssize_t ret = -EINVAL;
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unsigned long state = 0;
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ret = strict_strtoul(buf, 10, &state);
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if (!ret) {
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ret = size;
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if (state > LED_FULL)
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state = LED_FULL;
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led_cdev->max_brightness = state;
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led_set_brightness(led_cdev, led_cdev->brightness);
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}
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return ret;
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}
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static ssize_t led_max_brightness_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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return snprintf(buf, LED_BUFF_SIZE, "%u\n", led_cdev->max_brightness);
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}
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static struct device_attribute led_class_attrs[] = {
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__ATTR(brightness, 0644, led_brightness_show, led_brightness_store),
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__ATTR(max_brightness, 0644, led_max_brightness_show,
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led_max_brightness_store),
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#ifdef CONFIG_LEDS_TRIGGERS
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__ATTR(trigger, 0644, led_trigger_show, led_trigger_store),
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#endif
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__ATTR_NULL,
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};
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static void led_timer_function(unsigned long data)
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{
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struct led_classdev *led_cdev = (void *)data;
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unsigned long brightness;
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unsigned long delay;
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if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
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led_set_brightness(led_cdev, LED_OFF);
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return;
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}
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brightness = led_get_brightness(led_cdev);
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if (!brightness) {
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/* Time to switch the LED on. */
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brightness = led_cdev->blink_brightness;
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delay = led_cdev->blink_delay_on;
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} else {
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/* Store the current brightness value to be able
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* to restore it when the delay_off period is over.
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*/
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led_cdev->blink_brightness = brightness;
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brightness = LED_OFF;
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delay = led_cdev->blink_delay_off;
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}
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led_set_brightness(led_cdev, brightness);
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mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
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}
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/**
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* led_classdev_suspend - suspend an led_classdev.
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* @led_cdev: the led_classdev to suspend.
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*/
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void led_classdev_suspend(struct led_classdev *led_cdev)
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{
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led_cdev->flags |= LED_SUSPENDED;
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led_cdev->brightness_set(led_cdev, 0);
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}
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EXPORT_SYMBOL_GPL(led_classdev_suspend);
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/**
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* led_classdev_resume - resume an led_classdev.
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* @led_cdev: the led_classdev to resume.
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*/
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void led_classdev_resume(struct led_classdev *led_cdev)
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{
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led_cdev->brightness_set(led_cdev, led_cdev->brightness);
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led_cdev->flags &= ~LED_SUSPENDED;
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}
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EXPORT_SYMBOL_GPL(led_classdev_resume);
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static int led_suspend(struct device *dev, pm_message_t state)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
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led_classdev_suspend(led_cdev);
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return 0;
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}
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static int led_resume(struct device *dev)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
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led_classdev_resume(led_cdev);
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return 0;
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}
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/**
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* led_classdev_register - register a new object of led_classdev class.
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* @parent: The device to register.
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* @led_cdev: the led_classdev structure for this device.
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*/
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int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
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{
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led_cdev->dev = device_create(leds_class, parent, 0, led_cdev,
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"%s", led_cdev->name);
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if (IS_ERR(led_cdev->dev))
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return PTR_ERR(led_cdev->dev);
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#ifdef CONFIG_LEDS_TRIGGERS
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init_rwsem(&led_cdev->trigger_lock);
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#endif
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/* add to the list of leds */
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down_write(&leds_list_lock);
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list_add_tail(&led_cdev->node, &leds_list);
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up_write(&leds_list_lock);
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if (!led_cdev->max_brightness)
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led_cdev->max_brightness = LED_FULL;
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led_update_brightness(led_cdev);
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init_timer(&led_cdev->blink_timer);
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led_cdev->blink_timer.function = led_timer_function;
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led_cdev->blink_timer.data = (unsigned long)led_cdev;
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#ifdef CONFIG_LEDS_TRIGGERS
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led_trigger_set_default(led_cdev);
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#endif
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printk(KERN_DEBUG "Registered led device: %s\n",
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led_cdev->name);
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return 0;
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}
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EXPORT_SYMBOL_GPL(led_classdev_register);
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/**
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* led_classdev_unregister - unregisters a object of led_properties class.
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* @led_cdev: the led device to unregister
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*
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* Unregisters a previously registered via led_classdev_register object.
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*/
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void led_classdev_unregister(struct led_classdev *led_cdev)
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{
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#ifdef CONFIG_LEDS_TRIGGERS
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down_write(&led_cdev->trigger_lock);
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if (led_cdev->trigger)
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led_trigger_set(led_cdev, NULL);
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up_write(&led_cdev->trigger_lock);
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#endif
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/* Stop blinking */
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led_brightness_set(led_cdev, LED_OFF);
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device_unregister(led_cdev->dev);
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down_write(&leds_list_lock);
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list_del(&led_cdev->node);
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up_write(&leds_list_lock);
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}
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EXPORT_SYMBOL_GPL(led_classdev_unregister);
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static int __init leds_init(void)
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{
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leds_class = class_create(THIS_MODULE, "leds");
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if (IS_ERR(leds_class))
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return PTR_ERR(leds_class);
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leds_class->suspend = led_suspend;
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leds_class->resume = led_resume;
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leds_class->dev_attrs = led_class_attrs;
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return 0;
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}
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static void __exit leds_exit(void)
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{
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class_destroy(leds_class);
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}
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subsys_initcall(leds_init);
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module_exit(leds_exit);
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MODULE_AUTHOR("John Lenz, Richard Purdie");
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("LED Class Interface");
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