projects / linux.git / blame
| 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> | |
| 21 | #include "leds.h" | |
| 22 | ||
| 23 | struct heartbeat_trig_data { | |
| 24 | unsigned int phase; | |
| 25 | unsigned int period; | |
| 26 | struct timer_list timer; | |
| 27 | }; | |
| 28 | ||
| 29 | static void led_heartbeat_function(unsigned long data) | |
| 30 | { | |
| 31 | struct led_classdev *led_cdev = (struct led_classdev *) data; | |
| 32 | struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data; | |
| 33 | unsigned long brightness = LED_OFF; | |
| 34 | unsigned long delay = 0; | |
| 35 | ||
| 36 | /* acts like an actual heart beat -- ie thump-thump-pause... */ | |
| 37 | switch (heartbeat_data->phase) { | |
| 38 | case 0: | |
| 39 | /* | |
| 40 | * The hyperbolic function below modifies the | |
| 41 | * heartbeat period length in dependency of the | |
| 42 | * current (1min) load. It goes through the points | |
| 43 | * f(0)=1260, f(1)=860, f(5)=510, f(inf)->300. | |
| 44 | */ | |
| 45 | heartbeat_data->period = 300 + | |
| 46 | (6720 << FSHIFT) / (5 * avenrun[0] + (7 << FSHIFT)); | |
| 47 | heartbeat_data->period = | |
| 48 | msecs_to_jiffies(heartbeat_data->period); | |
| 49 | delay = msecs_to_jiffies(70); | |
| 50 | heartbeat_data->phase++; | |
| 1bd465e6 | 51 | brightness = led_cdev->max_brightness; |
| 891c668b AN |
52 | break; |
| 53 | case 1: | |
| 54 | delay = heartbeat_data->period / 4 - msecs_to_jiffies(70); | |
| 55 | heartbeat_data->phase++; | |
| 56 | break; | |
| 57 | case 2: | |
| 58 | delay = msecs_to_jiffies(70); | |
| 59 | heartbeat_data->phase++; | |
| 1bd465e6 | 60 | brightness = led_cdev->max_brightness; |
| 891c668b AN |
61 | break; |
| 62 | default: | |
| 63 | delay = heartbeat_data->period - heartbeat_data->period / 4 - | |
| 64 | msecs_to_jiffies(70); | |
| 65 | heartbeat_data->phase = 0; | |
| 66 | break; | |
| 67 | } | |
| 68 | ||
| 69 | led_set_brightness(led_cdev, brightness); | |
| 70 | mod_timer(&heartbeat_data->timer, jiffies + delay); | |
| 71 | } | |
| 72 | ||
| 73 | static void heartbeat_trig_activate(struct led_classdev *led_cdev) | |
| 74 | { | |
| 75 | struct heartbeat_trig_data *heartbeat_data; | |
| 76 | ||
| 77 | heartbeat_data = kzalloc(sizeof(*heartbeat_data), GFP_KERNEL); | |
| 78 | if (!heartbeat_data) | |
| 79 | return; | |
| 80 | ||
| 81 | led_cdev->trigger_data = heartbeat_data; | |
| 82 | setup_timer(&heartbeat_data->timer, | |
| 83 | led_heartbeat_function, (unsigned long) led_cdev); | |
| 84 | heartbeat_data->phase = 0; | |
| 85 | led_heartbeat_function(heartbeat_data->timer.data); | |
| 86 | } | |
| 87 | ||
| 88 | static void heartbeat_trig_deactivate(struct led_classdev *led_cdev) | |
| 89 | { | |
| 90 | struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data; | |
| 91 | ||
| 92 | if (heartbeat_data) { | |
| 93 | del_timer_sync(&heartbeat_data->timer); | |
| 94 | kfree(heartbeat_data); | |
| 95 | } | |
| 96 | } | |
| 97 | ||
| 98 | static struct led_trigger heartbeat_led_trigger = { | |
| 99 | .name = "heartbeat", | |
| 100 | .activate = heartbeat_trig_activate, | |
| 101 | .deactivate = heartbeat_trig_deactivate, | |
| 102 | }; | |
| 103 | ||
| 104 | static int __init heartbeat_trig_init(void) | |
| 105 | { | |
| 106 | return led_trigger_register(&heartbeat_led_trigger); | |
| 107 | } | |
| 108 | ||
| 109 | static void __exit heartbeat_trig_exit(void) | |
| 110 | { | |
| 111 | led_trigger_unregister(&heartbeat_led_trigger); | |
| 112 | } | |
| 113 | ||
| 114 | module_init(heartbeat_trig_init); | |
| 115 | module_exit(heartbeat_trig_exit); | |
| 116 | ||
| 117 | MODULE_AUTHOR("Atsushi Nemoto <[email protected]>"); | |
| 118 | MODULE_DESCRIPTION("Heartbeat LED trigger"); | |
| 119 | MODULE_LICENSE("GPL"); |