2 * LED Heartbeat Trigger
4 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
6 * Based on Richard Purdie's ledtrig-timer.c and some arch's
7 * CONFIG_HEARTBEAT code.
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.
14 #include <linux/module.h>
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/slab.h>
18 #include <linux/timer.h>
19 #include <linux/sched.h>
20 #include <linux/sched/loadavg.h>
21 #include <linux/leds.h>
22 #include <linux/reboot.h>
23 #include <linux/suspend.h>
26 static int panic_heartbeats;
28 struct heartbeat_trig_data {
31 struct timer_list timer;
35 static void led_heartbeat_function(unsigned long data)
37 struct led_classdev *led_cdev = (struct led_classdev *) data;
38 struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
39 unsigned long brightness = LED_OFF;
40 unsigned long delay = 0;
42 if (unlikely(panic_heartbeats)) {
43 led_set_brightness_nosleep(led_cdev, LED_OFF);
47 if (test_and_clear_bit(LED_BLINK_BRIGHTNESS_CHANGE, &led_cdev->work_flags))
48 led_cdev->blink_brightness = led_cdev->new_blink_brightness;
50 /* acts like an actual heart beat -- ie thump-thump-pause... */
51 switch (heartbeat_data->phase) {
54 * The hyperbolic function below modifies the
55 * heartbeat period length in dependency of the
56 * current (1min) load. It goes through the points
57 * f(0)=1260, f(1)=860, f(5)=510, f(inf)->300.
59 heartbeat_data->period = 300 +
60 (6720 << FSHIFT) / (5 * avenrun[0] + (7 << FSHIFT));
61 heartbeat_data->period =
62 msecs_to_jiffies(heartbeat_data->period);
63 delay = msecs_to_jiffies(70);
64 heartbeat_data->phase++;
65 if (!heartbeat_data->invert)
66 brightness = led_cdev->blink_brightness;
69 delay = heartbeat_data->period / 4 - msecs_to_jiffies(70);
70 heartbeat_data->phase++;
71 if (heartbeat_data->invert)
72 brightness = led_cdev->blink_brightness;
75 delay = msecs_to_jiffies(70);
76 heartbeat_data->phase++;
77 if (!heartbeat_data->invert)
78 brightness = led_cdev->blink_brightness;
81 delay = heartbeat_data->period - heartbeat_data->period / 4 -
83 heartbeat_data->phase = 0;
84 if (heartbeat_data->invert)
85 brightness = led_cdev->blink_brightness;
89 led_set_brightness_nosleep(led_cdev, brightness);
90 mod_timer(&heartbeat_data->timer, jiffies + delay);
93 static ssize_t led_invert_show(struct device *dev,
94 struct device_attribute *attr, char *buf)
96 struct led_classdev *led_cdev = dev_get_drvdata(dev);
97 struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
99 return sprintf(buf, "%u\n", heartbeat_data->invert);
102 static ssize_t led_invert_store(struct device *dev,
103 struct device_attribute *attr, const char *buf, size_t size)
105 struct led_classdev *led_cdev = dev_get_drvdata(dev);
106 struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
110 ret = kstrtoul(buf, 0, &state);
114 heartbeat_data->invert = !!state;
119 static DEVICE_ATTR(invert, 0644, led_invert_show, led_invert_store);
121 static void heartbeat_trig_activate(struct led_classdev *led_cdev)
123 struct heartbeat_trig_data *heartbeat_data;
126 heartbeat_data = kzalloc(sizeof(*heartbeat_data), GFP_KERNEL);
130 led_cdev->trigger_data = heartbeat_data;
131 rc = device_create_file(led_cdev->dev, &dev_attr_invert);
133 kfree(led_cdev->trigger_data);
137 setup_timer(&heartbeat_data->timer,
138 led_heartbeat_function, (unsigned long) led_cdev);
139 heartbeat_data->phase = 0;
140 if (!led_cdev->blink_brightness)
141 led_cdev->blink_brightness = led_cdev->max_brightness;
142 led_heartbeat_function(heartbeat_data->timer.data);
143 set_bit(LED_BLINK_SW, &led_cdev->work_flags);
144 led_cdev->activated = true;
147 static void heartbeat_trig_deactivate(struct led_classdev *led_cdev)
149 struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
151 if (led_cdev->activated) {
152 del_timer_sync(&heartbeat_data->timer);
153 device_remove_file(led_cdev->dev, &dev_attr_invert);
154 kfree(heartbeat_data);
155 clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
156 led_cdev->activated = false;
160 static struct led_trigger heartbeat_led_trigger = {
162 .activate = heartbeat_trig_activate,
163 .deactivate = heartbeat_trig_deactivate,
166 static int heartbeat_pm_notifier(struct notifier_block *nb,
167 unsigned long pm_event, void *unused)
172 case PM_SUSPEND_PREPARE:
173 case PM_HIBERNATION_PREPARE:
174 case PM_RESTORE_PREPARE:
175 led_trigger_unregister(&heartbeat_led_trigger);
177 case PM_POST_SUSPEND:
178 case PM_POST_HIBERNATION:
179 case PM_POST_RESTORE:
180 rc = led_trigger_register(&heartbeat_led_trigger);
182 pr_err("could not re-register heartbeat trigger\n");
190 static int heartbeat_reboot_notifier(struct notifier_block *nb,
191 unsigned long code, void *unused)
193 led_trigger_unregister(&heartbeat_led_trigger);
197 static int heartbeat_panic_notifier(struct notifier_block *nb,
198 unsigned long code, void *unused)
200 panic_heartbeats = 1;
204 static struct notifier_block heartbeat_pm_nb = {
205 .notifier_call = heartbeat_pm_notifier,
208 static struct notifier_block heartbeat_reboot_nb = {
209 .notifier_call = heartbeat_reboot_notifier,
212 static struct notifier_block heartbeat_panic_nb = {
213 .notifier_call = heartbeat_panic_notifier,
216 static int __init heartbeat_trig_init(void)
218 int rc = led_trigger_register(&heartbeat_led_trigger);
221 atomic_notifier_chain_register(&panic_notifier_list,
222 &heartbeat_panic_nb);
223 register_reboot_notifier(&heartbeat_reboot_nb);
224 register_pm_notifier(&heartbeat_pm_nb);
229 static void __exit heartbeat_trig_exit(void)
231 unregister_pm_notifier(&heartbeat_pm_nb);
232 unregister_reboot_notifier(&heartbeat_reboot_nb);
233 atomic_notifier_chain_unregister(&panic_notifier_list,
234 &heartbeat_panic_nb);
235 led_trigger_unregister(&heartbeat_led_trigger);
238 module_init(heartbeat_trig_init);
239 module_exit(heartbeat_trig_exit);
241 MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
242 MODULE_DESCRIPTION("Heartbeat LED trigger");
243 MODULE_LICENSE("GPL");