[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/slab.h>
#include <linux/timer.h>
#include <linux/sched.h>
#include <linux/leds.h>
#include <linux/reboot.h>
#include "leds.h"

static int panic_heartbeats;

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;

	if (unlikely(panic_heartbeats)) {
		led_set_brightness(led_cdev, LED_OFF);
		return;
	}

	/* 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);
	led_cdev->activated = true;
}

static void heartbeat_trig_deactivate(struct led_classdev *led_cdev)
{
	struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;

	if (led_cdev->activated) {
		del_timer_sync(&heartbeat_data->timer);
		kfree(heartbeat_data);
		led_cdev->activated = false;
	}
}

static struct led_trigger heartbeat_led_trigger = {
	.name     = "heartbeat",
	.activate = heartbeat_trig_activate,
	.deactivate = heartbeat_trig_deactivate,
};

static int heartbeat_reboot_notifier(struct notifier_block *nb,
				     unsigned long code, void *unused)
{
	led_trigger_unregister(&heartbeat_led_trigger);
	return NOTIFY_DONE;
}

static int heartbeat_panic_notifier(struct notifier_block *nb,
				     unsigned long code, void *unused)
{
	panic_heartbeats = 1;
	return NOTIFY_DONE;
}

static struct notifier_block heartbeat_reboot_nb = {
	.notifier_call = heartbeat_reboot_notifier,
};

static struct notifier_block heartbeat_panic_nb = {
	.notifier_call = heartbeat_panic_notifier,
};

static int __init heartbeat_trig_init(void)
{
	int rc = led_trigger_register(&heartbeat_led_trigger);

	if (!rc) {
		atomic_notifier_chain_register(&panic_notifier_list,
					       &heartbeat_panic_nb);
		register_reboot_notifier(&heartbeat_reboot_nb);
	}
	return rc;
}

static void __exit heartbeat_trig_exit(void)
{
	unregister_reboot_notifier(&heartbeat_reboot_nb);
	atomic_notifier_chain_unregister(&panic_notifier_list,
					 &heartbeat_panic_nb);
	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>
5a0e3ad6	17	#include <linux/slab.h>
891c668b AN	18	#include <linux/timer.h>
	19	#include <linux/sched.h>
	20	#include <linux/leds.h>
49dca5ae	21	#include <linux/reboot.h>
891c668b AN	22	#include "leds.h"
891c668b AN	23
fb31fbeb AH	24	static int panic_heartbeats;
fb31fbeb AH	25
891c668b AN	26	struct heartbeat_trig_data {
	27	unsigned int phase;
	28	unsigned int period;
	29	struct timer_list timer;
	30	};
	31
	32	static void led_heartbeat_function(unsigned long data)
	33	{
	34	struct led_classdev led_cdev = (struct led_classdev ) data;
	35	struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
	36	unsigned long brightness = LED_OFF;
	37	unsigned long delay = 0;
	38
fb31fbeb AH	39	if (unlikely(panic_heartbeats)) {
	40	led_set_brightness(led_cdev, LED_OFF);
	41	return;
	42	}
	43
891c668b AN	44	/* acts like an actual heart beat -- ie thump-thump-pause... */
	45	switch (heartbeat_data->phase) {
	46	case 0:
	47	/*
	48	* The hyperbolic function below modifies the
	49	* heartbeat period length in dependency of the
	50	* current (1min) load. It goes through the points
	51	* f(0)=1260, f(1)=860, f(5)=510, f(inf)->300.
	52	*/
	53	heartbeat_data->period = 300 +
	54	(6720 << FSHIFT) / (5 * avenrun[0] + (7 << FSHIFT));
	55	heartbeat_data->period =
	56	msecs_to_jiffies(heartbeat_data->period);
	57	delay = msecs_to_jiffies(70);
	58	heartbeat_data->phase++;
1bd465e6	59	brightness = led_cdev->max_brightness;
891c668b AN	60	break;
	61	case 1:
	62	delay = heartbeat_data->period / 4 - msecs_to_jiffies(70);
	63	heartbeat_data->phase++;
	64	break;
	65	case 2:
	66	delay = msecs_to_jiffies(70);
	67	heartbeat_data->phase++;
1bd465e6	68	brightness = led_cdev->max_brightness;
891c668b AN	69	break;
	70	default:
	71	delay = heartbeat_data->period - heartbeat_data->period / 4 -
	72	msecs_to_jiffies(70);
	73	heartbeat_data->phase = 0;
	74	break;
	75	}
	76
0da3e65b	77	__led_set_brightness(led_cdev, brightness);
891c668b AN	78	mod_timer(&heartbeat_data->timer, jiffies + delay);
	79	}
	80
	81	static void heartbeat_trig_activate(struct led_classdev *led_cdev)
	82	{
	83	struct heartbeat_trig_data *heartbeat_data;
	84
	85	heartbeat_data = kzalloc(sizeof(*heartbeat_data), GFP_KERNEL);
	86	if (!heartbeat_data)
	87	return;
	88
	89	led_cdev->trigger_data = heartbeat_data;
	90	setup_timer(&heartbeat_data->timer,
	91	led_heartbeat_function, (unsigned long) led_cdev);
	92	heartbeat_data->phase = 0;
	93	led_heartbeat_function(heartbeat_data->timer.data);
03c091e5	94	led_cdev->activated = true;
891c668b AN	95	}
	96
	97	static void heartbeat_trig_deactivate(struct led_classdev *led_cdev)
	98	{
	99	struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
	100
03c091e5	101	if (led_cdev->activated) {
891c668b AN	102	del_timer_sync(&heartbeat_data->timer);
891c668b AN	103	kfree(heartbeat_data);
03c091e5	104	led_cdev->activated = false;
891c668b AN	105	}
	106	}
	107
	108	static struct led_trigger heartbeat_led_trigger = {
	109	.name = "heartbeat",
	110	.activate = heartbeat_trig_activate,
	111	.deactivate = heartbeat_trig_deactivate,
	112	};
	113
49dca5ae AH	114	static int heartbeat_reboot_notifier(struct notifier_block *nb,
	115	unsigned long code, void *unused)
	116	{
	117	led_trigger_unregister(&heartbeat_led_trigger);
	118	return NOTIFY_DONE;
	119	}
	120
fb31fbeb AH	121	static int heartbeat_panic_notifier(struct notifier_block *nb,
	122	unsigned long code, void *unused)
	123	{
	124	panic_heartbeats = 1;
	125	return NOTIFY_DONE;
	126	}
	127
49dca5ae AH	128	static struct notifier_block heartbeat_reboot_nb = {
	129	.notifier_call = heartbeat_reboot_notifier,
	130	};
	131
	132	static struct notifier_block heartbeat_panic_nb = {
fb31fbeb	133	.notifier_call = heartbeat_panic_notifier,
49dca5ae AH	134	};
49dca5ae AH	135
891c668b AN	136	static int __init heartbeat_trig_init(void)
891c668b AN	137	{
49dca5ae AH	138	int rc = led_trigger_register(&heartbeat_led_trigger);
	139
	140	if (!rc) {
	141	atomic_notifier_chain_register(&panic_notifier_list,
	142	&heartbeat_panic_nb);
	143	register_reboot_notifier(&heartbeat_reboot_nb);
	144	}
	145	return rc;
891c668b AN	146	}
	147
	148	static void __exit heartbeat_trig_exit(void)
	149	{
49dca5ae AH	150	unregister_reboot_notifier(&heartbeat_reboot_nb);
	151	atomic_notifier_chain_unregister(&panic_notifier_list,
	152	&heartbeat_panic_nb);
891c668b AN	153	led_trigger_unregister(&heartbeat_led_trigger);
	154	}
	155
	156	module_init(heartbeat_trig_init);
	157	module_exit(heartbeat_trig_exit);
	158
	159	MODULE_AUTHOR("Atsushi Nemoto <[email protected]>");
	160	MODULE_DESCRIPTION("Heartbeat LED trigger");
	161	MODULE_LICENSE("GPL");