[linux.git] / drivers / leds / ledtrig-heartbeat.c

/*
 * LED Heartbeat Trigger
 *
 * Copyright (C) 2006 Atsushi Nemoto <[email protected]>
 *
 * 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 <[email protected]>");
MODULE_DESCRIPTION("Heartbeat LED trigger");
MODULE_LICENSE("GPL");
Commit	Line	Data
891c668b AN	1	/*
	2	* LED Heartbeat Trigger
	3	*
	4	* Copyright (C) 2006 Atsushi Nemoto <[email protected]>
	5	*
	6	* Based on Richard Purdie's ledtrig-timer.c and some arch's
	7	* CONFIG_HEARTBEAT code.
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License version 2 as
	11	* published by the Free Software Foundation.
	12	*
	13	*/
	14	#include <linux/module.h>
	15	#include <linux/kernel.h>
	16	#include <linux/init.h>
	17	#include <linux/timer.h>
	18	#include <linux/sched.h>
	19	#include <linux/leds.h>
	20	#include "leds.h"
	21
	22	struct heartbeat_trig_data {
	23	unsigned int phase;
	24	unsigned int period;
	25	struct timer_list timer;
	26	};
	27
	28	static void led_heartbeat_function(unsigned long data)
	29	{
	30	struct led_classdev led_cdev = (struct led_classdev ) data;
	31	struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
	32	unsigned long brightness = LED_OFF;
	33	unsigned long delay = 0;
	34
	35	/* acts like an actual heart beat -- ie thump-thump-pause... */
	36	switch (heartbeat_data->phase) {
	37	case 0:
	38	/*
	39	* The hyperbolic function below modifies the
	40	* heartbeat period length in dependency of the
	41	* current (1min) load. It goes through the points
	42	* f(0)=1260, f(1)=860, f(5)=510, f(inf)->300.
	43	*/
	44	heartbeat_data->period = 300 +
	45	(6720 << FSHIFT) / (5 * avenrun[0] + (7 << FSHIFT));
	46	heartbeat_data->period =
	47	msecs_to_jiffies(heartbeat_data->period);
	48	delay = msecs_to_jiffies(70);
	49	heartbeat_data->phase++;
1bd465e6	50	brightness = led_cdev->max_brightness;
891c668b AN	51	break;
	52	case 1:
	53	delay = heartbeat_data->period / 4 - msecs_to_jiffies(70);
	54	heartbeat_data->phase++;
	55	break;
	56	case 2:
	57	delay = msecs_to_jiffies(70);
	58	heartbeat_data->phase++;
1bd465e6	59	brightness = led_cdev->max_brightness;
891c668b AN	60	break;
	61	default:
	62	delay = heartbeat_data->period - heartbeat_data->period / 4 -
	63	msecs_to_jiffies(70);
	64	heartbeat_data->phase = 0;
	65	break;
	66	}
	67
	68	led_set_brightness(led_cdev, brightness);
	69	mod_timer(&heartbeat_data->timer, jiffies + delay);
	70	}
	71
	72	static void heartbeat_trig_activate(struct led_classdev *led_cdev)
	73	{
	74	struct heartbeat_trig_data *heartbeat_data;
	75
	76	heartbeat_data = kzalloc(sizeof(*heartbeat_data), GFP_KERNEL);
	77	if (!heartbeat_data)
	78	return;
	79
	80	led_cdev->trigger_data = heartbeat_data;
	81	setup_timer(&heartbeat_data->timer,
	82	led_heartbeat_function, (unsigned long) led_cdev);
	83	heartbeat_data->phase = 0;
	84	led_heartbeat_function(heartbeat_data->timer.data);
	85	}
	86
	87	static void heartbeat_trig_deactivate(struct led_classdev *led_cdev)
	88	{
	89	struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
	90
	91	if (heartbeat_data) {
	92	del_timer_sync(&heartbeat_data->timer);
	93	kfree(heartbeat_data);
	94	}
	95	}
	96
	97	static struct led_trigger heartbeat_led_trigger = {
	98	.name = "heartbeat",
	99	.activate = heartbeat_trig_activate,
	100	.deactivate = heartbeat_trig_deactivate,
	101	};
	102
	103	static int __init heartbeat_trig_init(void)
	104	{
	105	return led_trigger_register(&heartbeat_led_trigger);
	106	}
	107
	108	static void __exit heartbeat_trig_exit(void)
	109	{
	110	led_trigger_unregister(&heartbeat_led_trigger);
	111	}
	112
	113	module_init(heartbeat_trig_init);
	114	module_exit(heartbeat_trig_exit);
	115
	116	MODULE_AUTHOR("Atsushi Nemoto <[email protected]>");
	117	MODULE_DESCRIPTION("Heartbeat LED trigger");
	118	MODULE_LICENSE("GPL");