Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 891c668b authored by Atsushi Nemoto's avatar Atsushi Nemoto Committed by Linus Torvalds
Browse files

[PATCH] LED: add LED heartbeat trigger 



Add an LED trigger acts like a heart beat.  This can be used as a
replacement of CONFIG_HEARTBEAT code exists in some arch's timer code.

Signed-off-by: default avatarAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: default avatarRichard Purdie <rpurdie@rpsys.net>
Cc: "Nish Aravamudan" <nish.aravamudan@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent fa9799e3

drivers/leds/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -93,5 +93,14 @@ config LEDS_TRIGGER_IDE_DISK 
	  This allows LEDs to be controlled by IDE disk activity.

	  If unsure, say Y.



config LEDS_TRIGGER_HEARTBEAT

	tristate "LED Heartbeat Trigger"

	depends LEDS_TRIGGERS

	help

	  This allows LEDs to be controlled by a CPU load average.

	  The flash frequency is a hyperbolic function of the 1-minute

	  load average.

	  If unsure, say Y.



endmenu

drivers/leds/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -16,3 +16,4 @@ obj-$(CONFIG_LEDS_AMS_DELTA) += leds-ams-delta.o 
# LED Triggers

obj-$(CONFIG_LEDS_TRIGGER_TIMER)	+= ledtrig-timer.o

obj-$(CONFIG_LEDS_TRIGGER_IDE_DISK)	+= ledtrig-ide-disk.o

obj-$(CONFIG_LEDS_TRIGGER_HEARTBEAT)	+= ledtrig-heartbeat.o

drivers/leds/ledtrig-heartbeat.c

0 → 100644
+118 −0
Original line number Diff line number Diff line 
/*

 * 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_FULL;

		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_FULL;

		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");