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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * LED Heartbeat Trigger
4 *
5 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
6 *
7 * Based on Richard Purdie's ledtrig-timer.c and some arch's
8 * CONFIG_HEARTBEAT code.
9 */
10
11#include <linux/module.h>
12#include <linux/kernel.h>
13#include <linux/init.h>
14#include <linux/panic_notifier.h>
15#include <linux/slab.h>
16#include <linux/timer.h>
17#include <linux/sched.h>
18#include <linux/sched/loadavg.h>
19#include <linux/leds.h>
20#include <linux/reboot.h>
21#include "../leds.h"
22
23static int panic_heartbeats;
24
25struct heartbeat_trig_data {
26 struct led_classdev *led_cdev;
27 unsigned int phase;
28 unsigned int period;
29 struct timer_list timer;
30 unsigned int invert;
31};
32
33static void led_heartbeat_function(struct timer_list *t)
34{
35 struct heartbeat_trig_data *heartbeat_data =
36 from_timer(heartbeat_data, t, timer);
37 struct led_classdev *led_cdev;
38 unsigned long brightness = LED_OFF;
39 unsigned long delay = 0;
40
41 led_cdev = heartbeat_data->led_cdev;
42
43 if (unlikely(panic_heartbeats)) {
44 led_set_brightness_nosleep(led_cdev, LED_OFF);
45 return;
46 }
47
48 if (test_and_clear_bit(LED_BLINK_BRIGHTNESS_CHANGE, &led_cdev->work_flags))
49 led_cdev->blink_brightness = led_cdev->new_blink_brightness;
50
51 /* acts like an actual heart beat -- ie thump-thump-pause... */
52 switch (heartbeat_data->phase) {
53 case 0:
54 /*
55 * The hyperbolic function below modifies the
56 * heartbeat period length in dependency of the
57 * current (1min) load. It goes through the points
58 * f(0)=1260, f(1)=860, f(5)=510, f(inf)->300.
59 */
60 heartbeat_data->period = 300 +
61 (6720 << FSHIFT) / (5 * avenrun[0] + (7 << FSHIFT));
62 heartbeat_data->period =
63 msecs_to_jiffies(heartbeat_data->period);
64 delay = msecs_to_jiffies(70);
65 heartbeat_data->phase++;
66 if (!heartbeat_data->invert)
67 brightness = led_cdev->blink_brightness;
68 break;
69 case 1:
70 delay = heartbeat_data->period / 4 - msecs_to_jiffies(70);
71 heartbeat_data->phase++;
72 if (heartbeat_data->invert)
73 brightness = led_cdev->blink_brightness;
74 break;
75 case 2:
76 delay = msecs_to_jiffies(70);
77 heartbeat_data->phase++;
78 if (!heartbeat_data->invert)
79 brightness = led_cdev->blink_brightness;
80 break;
81 default:
82 delay = heartbeat_data->period - heartbeat_data->period / 4 -
83 msecs_to_jiffies(70);
84 heartbeat_data->phase = 0;
85 if (heartbeat_data->invert)
86 brightness = led_cdev->blink_brightness;
87 break;
88 }
89
90 led_set_brightness_nosleep(led_cdev, brightness);
91 mod_timer(&heartbeat_data->timer, jiffies + delay);
92}
93
94static ssize_t led_invert_show(struct device *dev,
95 struct device_attribute *attr, char *buf)
96{
97 struct heartbeat_trig_data *heartbeat_data =
98 led_trigger_get_drvdata(dev);
99
100 return sprintf(buf, "%u\n", heartbeat_data->invert);
101}
102
103static ssize_t led_invert_store(struct device *dev,
104 struct device_attribute *attr, const char *buf, size_t size)
105{
106 struct heartbeat_trig_data *heartbeat_data =
107 led_trigger_get_drvdata(dev);
108 unsigned long state;
109 int ret;
110
111 ret = kstrtoul(buf, 0, &state);
112 if (ret)
113 return ret;
114
115 heartbeat_data->invert = !!state;
116
117 return size;
118}
119
120static DEVICE_ATTR(invert, 0644, led_invert_show, led_invert_store);
121
122static struct attribute *heartbeat_trig_attrs[] = {
123 &dev_attr_invert.attr,
124 NULL
125};
126ATTRIBUTE_GROUPS(heartbeat_trig);
127
128static int heartbeat_trig_activate(struct led_classdev *led_cdev)
129{
130 struct heartbeat_trig_data *heartbeat_data;
131
132 heartbeat_data = kzalloc(sizeof(*heartbeat_data), GFP_KERNEL);
133 if (!heartbeat_data)
134 return -ENOMEM;
135
136 led_set_trigger_data(led_cdev, heartbeat_data);
137 heartbeat_data->led_cdev = led_cdev;
138
139 timer_setup(&heartbeat_data->timer, led_heartbeat_function, 0);
140 heartbeat_data->phase = 0;
141 if (!led_cdev->blink_brightness)
142 led_cdev->blink_brightness = led_cdev->max_brightness;
143 led_heartbeat_function(&heartbeat_data->timer);
144 set_bit(LED_BLINK_SW, &led_cdev->work_flags);
145
146 return 0;
147}
148
149static void heartbeat_trig_deactivate(struct led_classdev *led_cdev)
150{
151 struct heartbeat_trig_data *heartbeat_data =
152 led_get_trigger_data(led_cdev);
153
154 timer_shutdown_sync(&heartbeat_data->timer);
155 kfree(heartbeat_data);
156 clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
157}
158
159static struct led_trigger heartbeat_led_trigger = {
160 .name = "heartbeat",
161 .activate = heartbeat_trig_activate,
162 .deactivate = heartbeat_trig_deactivate,
163 .groups = heartbeat_trig_groups,
164};
165
166static int heartbeat_reboot_notifier(struct notifier_block *nb,
167 unsigned long code, void *unused)
168{
169 led_trigger_unregister(&heartbeat_led_trigger);
170 return NOTIFY_DONE;
171}
172
173static int heartbeat_panic_notifier(struct notifier_block *nb,
174 unsigned long code, void *unused)
175{
176 panic_heartbeats = 1;
177 return NOTIFY_DONE;
178}
179
180static struct notifier_block heartbeat_reboot_nb = {
181 .notifier_call = heartbeat_reboot_notifier,
182};
183
184static struct notifier_block heartbeat_panic_nb = {
185 .notifier_call = heartbeat_panic_notifier,
186};
187
188static int __init heartbeat_trig_init(void)
189{
190 int rc = led_trigger_register(&heartbeat_led_trigger);
191
192 if (!rc) {
193 atomic_notifier_chain_register(&panic_notifier_list,
194 &heartbeat_panic_nb);
195 register_reboot_notifier(&heartbeat_reboot_nb);
196 }
197 return rc;
198}
199
200static void __exit heartbeat_trig_exit(void)
201{
202 unregister_reboot_notifier(&heartbeat_reboot_nb);
203 atomic_notifier_chain_unregister(&panic_notifier_list,
204 &heartbeat_panic_nb);
205 led_trigger_unregister(&heartbeat_led_trigger);
206}
207
208module_init(heartbeat_trig_init);
209module_exit(heartbeat_trig_exit);
210
211MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
212MODULE_DESCRIPTION("Heartbeat LED trigger");
213MODULE_LICENSE("GPL v2");
1/*
2 * LED Heartbeat Trigger
3 *
4 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
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/slab.h>
18#include <linux/timer.h>
19#include <linux/sched.h>
20#include <linux/leds.h>
21#include <linux/reboot.h>
22#include "../leds.h"
23
24static int panic_heartbeats;
25
26struct heartbeat_trig_data {
27 unsigned int phase;
28 unsigned int period;
29 struct timer_list timer;
30 unsigned int invert;
31};
32
33static void led_heartbeat_function(unsigned long data)
34{
35 struct led_classdev *led_cdev = (struct led_classdev *) data;
36 struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
37 unsigned long brightness = LED_OFF;
38 unsigned long delay = 0;
39
40 if (unlikely(panic_heartbeats)) {
41 led_set_brightness_nosleep(led_cdev, LED_OFF);
42 return;
43 }
44
45 /* acts like an actual heart beat -- ie thump-thump-pause... */
46 switch (heartbeat_data->phase) {
47 case 0:
48 /*
49 * The hyperbolic function below modifies the
50 * heartbeat period length in dependency of the
51 * current (1min) load. It goes through the points
52 * f(0)=1260, f(1)=860, f(5)=510, f(inf)->300.
53 */
54 heartbeat_data->period = 300 +
55 (6720 << FSHIFT) / (5 * avenrun[0] + (7 << FSHIFT));
56 heartbeat_data->period =
57 msecs_to_jiffies(heartbeat_data->period);
58 delay = msecs_to_jiffies(70);
59 heartbeat_data->phase++;
60 if (!heartbeat_data->invert)
61 brightness = led_cdev->max_brightness;
62 break;
63 case 1:
64 delay = heartbeat_data->period / 4 - msecs_to_jiffies(70);
65 heartbeat_data->phase++;
66 if (heartbeat_data->invert)
67 brightness = led_cdev->max_brightness;
68 break;
69 case 2:
70 delay = msecs_to_jiffies(70);
71 heartbeat_data->phase++;
72 if (!heartbeat_data->invert)
73 brightness = led_cdev->max_brightness;
74 break;
75 default:
76 delay = heartbeat_data->period - heartbeat_data->period / 4 -
77 msecs_to_jiffies(70);
78 heartbeat_data->phase = 0;
79 if (heartbeat_data->invert)
80 brightness = led_cdev->max_brightness;
81 break;
82 }
83
84 led_set_brightness_nosleep(led_cdev, brightness);
85 mod_timer(&heartbeat_data->timer, jiffies + delay);
86}
87
88static ssize_t led_invert_show(struct device *dev,
89 struct device_attribute *attr, char *buf)
90{
91 struct led_classdev *led_cdev = dev_get_drvdata(dev);
92 struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
93
94 return sprintf(buf, "%u\n", heartbeat_data->invert);
95}
96
97static ssize_t led_invert_store(struct device *dev,
98 struct device_attribute *attr, const char *buf, size_t size)
99{
100 struct led_classdev *led_cdev = dev_get_drvdata(dev);
101 struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
102 unsigned long state;
103 int ret;
104
105 ret = kstrtoul(buf, 0, &state);
106 if (ret)
107 return ret;
108
109 heartbeat_data->invert = !!state;
110
111 return size;
112}
113
114static DEVICE_ATTR(invert, 0644, led_invert_show, led_invert_store);
115
116static void heartbeat_trig_activate(struct led_classdev *led_cdev)
117{
118 struct heartbeat_trig_data *heartbeat_data;
119 int rc;
120
121 heartbeat_data = kzalloc(sizeof(*heartbeat_data), GFP_KERNEL);
122 if (!heartbeat_data)
123 return;
124
125 led_cdev->trigger_data = heartbeat_data;
126 rc = device_create_file(led_cdev->dev, &dev_attr_invert);
127 if (rc) {
128 kfree(led_cdev->trigger_data);
129 return;
130 }
131
132 setup_timer(&heartbeat_data->timer,
133 led_heartbeat_function, (unsigned long) led_cdev);
134 heartbeat_data->phase = 0;
135 led_heartbeat_function(heartbeat_data->timer.data);
136 led_cdev->activated = true;
137}
138
139static void heartbeat_trig_deactivate(struct led_classdev *led_cdev)
140{
141 struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
142
143 if (led_cdev->activated) {
144 del_timer_sync(&heartbeat_data->timer);
145 device_remove_file(led_cdev->dev, &dev_attr_invert);
146 kfree(heartbeat_data);
147 led_cdev->activated = false;
148 }
149}
150
151static struct led_trigger heartbeat_led_trigger = {
152 .name = "heartbeat",
153 .activate = heartbeat_trig_activate,
154 .deactivate = heartbeat_trig_deactivate,
155};
156
157static int heartbeat_reboot_notifier(struct notifier_block *nb,
158 unsigned long code, void *unused)
159{
160 led_trigger_unregister(&heartbeat_led_trigger);
161 return NOTIFY_DONE;
162}
163
164static int heartbeat_panic_notifier(struct notifier_block *nb,
165 unsigned long code, void *unused)
166{
167 panic_heartbeats = 1;
168 return NOTIFY_DONE;
169}
170
171static struct notifier_block heartbeat_reboot_nb = {
172 .notifier_call = heartbeat_reboot_notifier,
173};
174
175static struct notifier_block heartbeat_panic_nb = {
176 .notifier_call = heartbeat_panic_notifier,
177};
178
179static int __init heartbeat_trig_init(void)
180{
181 int rc = led_trigger_register(&heartbeat_led_trigger);
182
183 if (!rc) {
184 atomic_notifier_chain_register(&panic_notifier_list,
185 &heartbeat_panic_nb);
186 register_reboot_notifier(&heartbeat_reboot_nb);
187 }
188 return rc;
189}
190
191static void __exit heartbeat_trig_exit(void)
192{
193 unregister_reboot_notifier(&heartbeat_reboot_nb);
194 atomic_notifier_chain_unregister(&panic_notifier_list,
195 &heartbeat_panic_nb);
196 led_trigger_unregister(&heartbeat_led_trigger);
197}
198
199module_init(heartbeat_trig_init);
200module_exit(heartbeat_trig_exit);
201
202MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
203MODULE_DESCRIPTION("Heartbeat LED trigger");
204MODULE_LICENSE("GPL");