mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-19 10:14:23 +08:00
111 lines
2.4 KiB
C
111 lines
2.4 KiB
C
|
/*
|
||
|
|
* Backlight emulation LED trigger
|
||
|
|
*
|
||
|
|
* Copyright 2008 (C) Rodolfo Giometti <giometti@linux.it>
|
||
|
|
* Copyright 2008 (C) Eurotech S.p.A. <info@eurotech.it>
|
||
|
|
*
|
||
|
|
* 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/fb.h>
|
||
|
|
#include <linux/leds.h>
|
||
|
|
#include "leds.h"
|
||
|
|
|
||
|
|
#define BLANK 1
|
||
|
|
#define UNBLANK 0
|
||
|
|
|
||
|
|
struct bl_trig_notifier {
|
||
|
|
struct led_classdev *led;
|
||
|
|
int brightness;
|
||
|
|
int old_status;
|
||
|
|
struct notifier_block notifier;
|
||
|
|
};
|
||
|
|
|
||
|
|
static int fb_notifier_callback(struct notifier_block *p,
|
||
|
|
unsigned long event, void *data)
|
||
|
|
{
|
||
|
|
struct bl_trig_notifier *n = container_of(p,
|
||
|
|
struct bl_trig_notifier, notifier);
|
||
|
|
struct led_classdev *led = n->led;
|
||
|
|
struct fb_event *fb_event = data;
|
||
|
|
int *blank = fb_event->data;
|
||
|
|
|
||
|
|
switch (event) {
|
||
|
|
case FB_EVENT_BLANK :
|
||
|
|
if (*blank && n->old_status == UNBLANK) {
|
||
|
|
n->brightness = led->brightness;
|
||
|
|
led_set_brightness(led, LED_OFF);
|
||
|
|
n->old_status = BLANK;
|
||
|
|
} else if (!*blank && n->old_status == BLANK) {
|
||
|
|
led_set_brightness(led, n->brightness);
|
||
|
|
n->old_status = UNBLANK;
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void bl_trig_activate(struct led_classdev *led)
|
||
|
|
{
|
||
|
|
int ret;
|
||
|
|
|
||
|
|
struct bl_trig_notifier *n;
|
||
|
|
|
||
|
|
n = kzalloc(sizeof(struct bl_trig_notifier), GFP_KERNEL);
|
||
|
|
led->trigger_data = n;
|
||
|
|
if (!n) {
|
||
|
|
dev_err(led->dev, "unable to allocate backlight trigger\n");
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
n->led = led;
|
||
|
|
n->brightness = led->brightness;
|
||
|
|
n->old_status = UNBLANK;
|
||
|
|
n->notifier.notifier_call = fb_notifier_callback;
|
||
|
|
|
||
|
|
ret = fb_register_client(&n->notifier);
|
||
|
|
if (ret)
|
||
|
|
dev_err(led->dev, "unable to register backlight trigger\n");
|
||
|
|
}
|
||
|
|
|
||
|
|
static void bl_trig_deactivate(struct led_classdev *led)
|
||
|
|
{
|
||
|
|
struct bl_trig_notifier *n =
|
||
|
|
(struct bl_trig_notifier *) led->trigger_data;
|
||
|
|
|
||
|
|
if (n) {
|
||
|
|
fb_unregister_client(&n->notifier);
|
||
|
|
kfree(n);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
static struct led_trigger bl_led_trigger = {
|
||
|
|
.name = "backlight",
|
||
|
|
.activate = bl_trig_activate,
|
||
|
|
.deactivate = bl_trig_deactivate
|
||
|
|
};
|
||
|
|
|
||
|
|
static int __init bl_trig_init(void)
|
||
|
|
{
|
||
|
|
return led_trigger_register(&bl_led_trigger);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void __exit bl_trig_exit(void)
|
||
|
|
{
|
||
|
|
led_trigger_unregister(&bl_led_trigger);
|
||
|
|
}
|
||
|
|
|
||
|
|
module_init(bl_trig_init);
|
||
|
|
module_exit(bl_trig_exit);
|
||
|
|
|
||
|
|
MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
|
||
|
|
MODULE_DESCRIPTION("Backlight emulation LED trigger");
|
||
|
|
MODULE_LICENSE("GPL v2");
|