led-core.c

Go to the documentation of this file.

/*
 * LED Class Core
 *
 * Copyright 2005-2006 Openedhand Ltd.
 *
 * Author: Richard Purdie <[email protected]>
 *
 * 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/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/rwsem.h>
#include <linux/leds.h>
#include "leds.h"

DECLARE_RWSEM(leds_list_lock);
EXPORT_SYMBOL_GPL(leds_list_lock);

LIST_HEAD(leds_list);
EXPORT_SYMBOL_GPL(leds_list);

static void led_set_software_blink(struct led_classdev *led_cdev,
                   unsigned long delay_on,
                   unsigned long delay_off)
{
    int current_brightness;

    current_brightness = led_get_brightness(led_cdev);
    if (current_brightness)
        led_cdev->blink_brightness = current_brightness;
    if (!led_cdev->blink_brightness)
        led_cdev->blink_brightness = led_cdev->max_brightness;

    led_cdev->blink_delay_on = delay_on;
    led_cdev->blink_delay_off = delay_off;

    /* never on - don't blink */
    if (!delay_on)
        return;

    /* never off - just set to brightness */
    if (!delay_off) {
        __led_set_brightness(led_cdev, led_cdev->blink_brightness);
        return;
    }

    mod_timer(&led_cdev->blink_timer, jiffies + 1);
}


static void led_blink_setup(struct led_classdev *led_cdev,
             unsigned long *delay_on,
             unsigned long *delay_off)
{
    if (!(led_cdev->flags & LED_BLINK_ONESHOT) &&
        led_cdev->blink_set &&
        !led_cdev->blink_set(led_cdev, delay_on, delay_off))
        return;

    /* blink with 1 Hz as default if nothing specified */
    if (!*delay_on && !*delay_off)
        *delay_on = *delay_off = 500;

    led_set_software_blink(led_cdev, *delay_on, *delay_off);
}

void led_blink_set(struct led_classdev *led_cdev,
           unsigned long *delay_on,
           unsigned long *delay_off)
{
    del_timer_sync(&led_cdev->blink_timer);

    led_cdev->flags &= ~LED_BLINK_ONESHOT;
    led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;

    led_blink_setup(led_cdev, delay_on, delay_off);
}
EXPORT_SYMBOL(led_blink_set);

void led_blink_set_oneshot(struct led_classdev *led_cdev,
               unsigned long *delay_on,
               unsigned long *delay_off,
               int invert)
{
    if ((led_cdev->flags & LED_BLINK_ONESHOT) &&
         timer_pending(&led_cdev->blink_timer))
        return;

    led_cdev->flags |= LED_BLINK_ONESHOT;
    led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;

    if (invert)
        led_cdev->flags |= LED_BLINK_INVERT;
    else
        led_cdev->flags &= ~LED_BLINK_INVERT;

    led_blink_setup(led_cdev, delay_on, delay_off);
}
EXPORT_SYMBOL(led_blink_set_oneshot);

void led_stop_software_blink(struct led_classdev *led_cdev)
{
    del_timer_sync(&led_cdev->blink_timer);
    led_cdev->blink_delay_on = 0;
    led_cdev->blink_delay_off = 0;
}
EXPORT_SYMBOL_GPL(led_stop_software_blink);

void led_set_brightness(struct led_classdev *led_cdev,
            enum led_brightness brightness)
{
    /* delay brightness setting if need to stop soft-blink timer */
    if (led_cdev->blink_delay_on || led_cdev->blink_delay_off) {
        led_cdev->delayed_set_value = brightness;
        schedule_work(&led_cdev->set_brightness_work);
        return;
    }

    __led_set_brightness(led_cdev, brightness);
}
EXPORT_SYMBOL(led_set_brightness);