linux-imx

/*

 * LED Class Core

 *

 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>

 * Copyright (C) 2005-2007 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/ctype.h>

#include <linux/device.h>

#include <linux/err.h>

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/leds.h>

#include <linux/list.h>

#include <linux/module.h>

#include <linux/slab.h>

#include <linux/spinlock.h>

#include <linux/timer.h>

#include <uapi/linux/uleds.h>

#include "leds.h"

​

static struct class *leds_class;

​

static ssize_t brightness_show(struct device *dev,

        struct device_attribute *attr, char *buf)

{

    struct led_classdev *led_cdev = dev_get_drvdata(dev);

​

    /* no lock needed for this */

    led_update_brightness(led_cdev);

​

    return sprintf(buf, "%u\n", led_cdev->brightness);

}

​

static ssize_t brightness_store(struct device *dev,

        struct device_attribute *attr, const char *buf, size_t size)

{

    struct led_classdev *led_cdev = dev_get_drvdata(dev);

    unsigned long state;

    ssize_t ret;

​

    mutex_lock(&led_cdev->led_access);

​

    if (led_sysfs_is_disabled(led_cdev)) {

        ret = -EBUSY;

        goto unlock;

    }

​

    ret = kstrtoul(buf, 10, &state);

    if (ret)

        goto unlock;

​

    if (state == LED_OFF)

        led_trigger_remove(led_cdev);

    led_set_brightness(led_cdev, state);

​

    ret = size;

unlock:

    mutex_unlock(&led_cdev->led_access);