1bd465e6b0
This patch allows drivers to override the default maximum brightness value of 255. We take care to preserve backwards-compatibility as much as possible, so that user-space ABI doesn't change for existing drivers. LED trigger code has also been updated to use the per-LED maximum. Signed-off-by: Guennadi Liakhovetski <lg@denx.de> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
118 lines
3.1 KiB
C
118 lines
3.1 KiB
C
/*
|
|
* LED Heartbeat Trigger
|
|
*
|
|
* Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
|
|
*
|
|
* Based on Richard Purdie's ledtrig-timer.c and some arch's
|
|
* CONFIG_HEARTBEAT code.
|
|
*
|
|
* 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/timer.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/leds.h>
|
|
#include "leds.h"
|
|
|
|
struct heartbeat_trig_data {
|
|
unsigned int phase;
|
|
unsigned int period;
|
|
struct timer_list timer;
|
|
};
|
|
|
|
static void led_heartbeat_function(unsigned long data)
|
|
{
|
|
struct led_classdev *led_cdev = (struct led_classdev *) data;
|
|
struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
|
|
unsigned long brightness = LED_OFF;
|
|
unsigned long delay = 0;
|
|
|
|
/* acts like an actual heart beat -- ie thump-thump-pause... */
|
|
switch (heartbeat_data->phase) {
|
|
case 0:
|
|
/*
|
|
* The hyperbolic function below modifies the
|
|
* heartbeat period length in dependency of the
|
|
* current (1min) load. It goes through the points
|
|
* f(0)=1260, f(1)=860, f(5)=510, f(inf)->300.
|
|
*/
|
|
heartbeat_data->period = 300 +
|
|
(6720 << FSHIFT) / (5 * avenrun[0] + (7 << FSHIFT));
|
|
heartbeat_data->period =
|
|
msecs_to_jiffies(heartbeat_data->period);
|
|
delay = msecs_to_jiffies(70);
|
|
heartbeat_data->phase++;
|
|
brightness = led_cdev->max_brightness;
|
|
break;
|
|
case 1:
|
|
delay = heartbeat_data->period / 4 - msecs_to_jiffies(70);
|
|
heartbeat_data->phase++;
|
|
break;
|
|
case 2:
|
|
delay = msecs_to_jiffies(70);
|
|
heartbeat_data->phase++;
|
|
brightness = led_cdev->max_brightness;
|
|
break;
|
|
default:
|
|
delay = heartbeat_data->period - heartbeat_data->period / 4 -
|
|
msecs_to_jiffies(70);
|
|
heartbeat_data->phase = 0;
|
|
break;
|
|
}
|
|
|
|
led_set_brightness(led_cdev, brightness);
|
|
mod_timer(&heartbeat_data->timer, jiffies + delay);
|
|
}
|
|
|
|
static void heartbeat_trig_activate(struct led_classdev *led_cdev)
|
|
{
|
|
struct heartbeat_trig_data *heartbeat_data;
|
|
|
|
heartbeat_data = kzalloc(sizeof(*heartbeat_data), GFP_KERNEL);
|
|
if (!heartbeat_data)
|
|
return;
|
|
|
|
led_cdev->trigger_data = heartbeat_data;
|
|
setup_timer(&heartbeat_data->timer,
|
|
led_heartbeat_function, (unsigned long) led_cdev);
|
|
heartbeat_data->phase = 0;
|
|
led_heartbeat_function(heartbeat_data->timer.data);
|
|
}
|
|
|
|
static void heartbeat_trig_deactivate(struct led_classdev *led_cdev)
|
|
{
|
|
struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
|
|
|
|
if (heartbeat_data) {
|
|
del_timer_sync(&heartbeat_data->timer);
|
|
kfree(heartbeat_data);
|
|
}
|
|
}
|
|
|
|
static struct led_trigger heartbeat_led_trigger = {
|
|
.name = "heartbeat",
|
|
.activate = heartbeat_trig_activate,
|
|
.deactivate = heartbeat_trig_deactivate,
|
|
};
|
|
|
|
static int __init heartbeat_trig_init(void)
|
|
{
|
|
return led_trigger_register(&heartbeat_led_trigger);
|
|
}
|
|
|
|
static void __exit heartbeat_trig_exit(void)
|
|
{
|
|
led_trigger_unregister(&heartbeat_led_trigger);
|
|
}
|
|
|
|
module_init(heartbeat_trig_init);
|
|
module_exit(heartbeat_trig_exit);
|
|
|
|
MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
|
|
MODULE_DESCRIPTION("Heartbeat LED trigger");
|
|
MODULE_LICENSE("GPL");
|