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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 <linux/suspend.h>
23#include "../leds.h"
24
25static int panic_heartbeats;
26
27struct heartbeat_trig_data {
28 unsigned int phase;
29 unsigned int period;
30 struct timer_list timer;
31 unsigned int invert;
32};
33
34static void led_heartbeat_function(unsigned long data)
35{
36 struct led_classdev *led_cdev = (struct led_classdev *) data;
37 struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
38 unsigned long brightness = LED_OFF;
39 unsigned long delay = 0;
40
41 if (unlikely(panic_heartbeats)) {
42 led_set_brightness_nosleep(led_cdev, LED_OFF);
43 return;
44 }
45
46 /* acts like an actual heart beat -- ie thump-thump-pause... */
47 switch (heartbeat_data->phase) {
48 case 0:
49 /*
50 * The hyperbolic function below modifies the
51 * heartbeat period length in dependency of the
52 * current (1min) load. It goes through the points
53 * f(0)=1260, f(1)=860, f(5)=510, f(inf)->300.
54 */
55 heartbeat_data->period = 300 +
56 (6720 << FSHIFT) / (5 * avenrun[0] + (7 << FSHIFT));
57 heartbeat_data->period =
58 msecs_to_jiffies(heartbeat_data->period);
59 delay = msecs_to_jiffies(70);
60 heartbeat_data->phase++;
61 if (!heartbeat_data->invert)
62 brightness = led_cdev->max_brightness;
63 break;
64 case 1:
65 delay = heartbeat_data->period / 4 - msecs_to_jiffies(70);
66 heartbeat_data->phase++;
67 if (heartbeat_data->invert)
68 brightness = led_cdev->max_brightness;
69 break;
70 case 2:
71 delay = msecs_to_jiffies(70);
72 heartbeat_data->phase++;
73 if (!heartbeat_data->invert)
74 brightness = led_cdev->max_brightness;
75 break;
76 default:
77 delay = heartbeat_data->period - heartbeat_data->period / 4 -
78 msecs_to_jiffies(70);
79 heartbeat_data->phase = 0;
80 if (heartbeat_data->invert)
81 brightness = led_cdev->max_brightness;
82 break;
83 }
84
85 led_set_brightness_nosleep(led_cdev, brightness);
86 mod_timer(&heartbeat_data->timer, jiffies + delay);
87}
88
89static ssize_t led_invert_show(struct device *dev,
90 struct device_attribute *attr, char *buf)
91{
92 struct led_classdev *led_cdev = dev_get_drvdata(dev);
93 struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
94
95 return sprintf(buf, "%u\n", heartbeat_data->invert);
96}
97
98static ssize_t led_invert_store(struct device *dev,
99 struct device_attribute *attr, const char *buf, size_t size)
100{
101 struct led_classdev *led_cdev = dev_get_drvdata(dev);
102 struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
103 unsigned long state;
104 int ret;
105
106 ret = kstrtoul(buf, 0, &state);
107 if (ret)
108 return ret;
109
110 heartbeat_data->invert = !!state;
111
112 return size;
113}
114
115static DEVICE_ATTR(invert, 0644, led_invert_show, led_invert_store);
116
117static void heartbeat_trig_activate(struct led_classdev *led_cdev)
118{
119 struct heartbeat_trig_data *heartbeat_data;
120 int rc;
121
122 heartbeat_data = kzalloc(sizeof(*heartbeat_data), GFP_KERNEL);
123 if (!heartbeat_data)
124 return;
125
126 led_cdev->trigger_data = heartbeat_data;
127 rc = device_create_file(led_cdev->dev, &dev_attr_invert);
128 if (rc) {
129 kfree(led_cdev->trigger_data);
130 return;
131 }
132
133 setup_timer(&heartbeat_data->timer,
134 led_heartbeat_function, (unsigned long) led_cdev);
135 heartbeat_data->phase = 0;
136 led_heartbeat_function(heartbeat_data->timer.data);
137 led_cdev->activated = true;
138}
139
140static void heartbeat_trig_deactivate(struct led_classdev *led_cdev)
141{
142 struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
143
144 if (led_cdev->activated) {
145 del_timer_sync(&heartbeat_data->timer);
146 device_remove_file(led_cdev->dev, &dev_attr_invert);
147 kfree(heartbeat_data);
148 led_cdev->activated = false;
149 }
150}
151
152static struct led_trigger heartbeat_led_trigger = {
153 .name = "heartbeat",
154 .activate = heartbeat_trig_activate,
155 .deactivate = heartbeat_trig_deactivate,
156};
157
158static int heartbeat_pm_notifier(struct notifier_block *nb,
159 unsigned long pm_event, void *unused)
160{
161 int rc;
162
163 switch (pm_event) {
164 case PM_SUSPEND_PREPARE:
165 case PM_HIBERNATION_PREPARE:
166 case PM_RESTORE_PREPARE:
167 led_trigger_unregister(&heartbeat_led_trigger);
168 break;
169 case PM_POST_SUSPEND:
170 case PM_POST_HIBERNATION:
171 case PM_POST_RESTORE:
172 rc = led_trigger_register(&heartbeat_led_trigger);
173 if (rc)
174 pr_err("could not re-register heartbeat trigger\n");
175 break;
176 default:
177 break;
178 }
179 return NOTIFY_DONE;
180}
181
182static int heartbeat_reboot_notifier(struct notifier_block *nb,
183 unsigned long code, void *unused)
184{
185 led_trigger_unregister(&heartbeat_led_trigger);
186 return NOTIFY_DONE;
187}
188
189static int heartbeat_panic_notifier(struct notifier_block *nb,
190 unsigned long code, void *unused)
191{
192 panic_heartbeats = 1;
193 return NOTIFY_DONE;
194}
195
196static struct notifier_block heartbeat_pm_nb = {
197 .notifier_call = heartbeat_pm_notifier,
198};
199
200static struct notifier_block heartbeat_reboot_nb = {
201 .notifier_call = heartbeat_reboot_notifier,
202};
203
204static struct notifier_block heartbeat_panic_nb = {
205 .notifier_call = heartbeat_panic_notifier,
206};
207
208static int __init heartbeat_trig_init(void)
209{
210 int rc = led_trigger_register(&heartbeat_led_trigger);
211
212 if (!rc) {
213 atomic_notifier_chain_register(&panic_notifier_list,
214 &heartbeat_panic_nb);
215 register_reboot_notifier(&heartbeat_reboot_nb);
216 register_pm_notifier(&heartbeat_pm_nb);
217 }
218 return rc;
219}
220
221static void __exit heartbeat_trig_exit(void)
222{
223 unregister_pm_notifier(&heartbeat_pm_nb);
224 unregister_reboot_notifier(&heartbeat_reboot_nb);
225 atomic_notifier_chain_unregister(&panic_notifier_list,
226 &heartbeat_panic_nb);
227 led_trigger_unregister(&heartbeat_led_trigger);
228}
229
230module_init(heartbeat_trig_init);
231module_exit(heartbeat_trig_exit);
232
233MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
234MODULE_DESCRIPTION("Heartbeat LED trigger");
235MODULE_LICENSE("GPL");