1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* 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.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/panic_notifier.h>
#include <linux/slab.h>
#include <linux/timer.h>
#include <linux/sched.h>
#include <linux/sched/loadavg.h>
#include <linux/leds.h>
#include <linux/reboot.h>
#include "../leds.h"
static int panic_heartbeats;
struct heartbeat_trig_data {
struct led_classdev *led_cdev;
unsigned int phase;
unsigned int period;
struct timer_list timer;
unsigned int invert;
};
static void led_heartbeat_function(struct timer_list *t)
{
struct heartbeat_trig_data *heartbeat_data =
from_timer(heartbeat_data, t, timer);
struct led_classdev *led_cdev;
unsigned long brightness = LED_OFF;
unsigned long delay = 0;
led_cdev = heartbeat_data->led_cdev;
if (unlikely(panic_heartbeats)) {
led_set_brightness_nosleep(led_cdev, LED_OFF);
return;
}
if (test_and_clear_bit(LED_BLINK_BRIGHTNESS_CHANGE, &led_cdev->work_flags))
led_cdev->blink_brightness = led_cdev->new_blink_brightness;
/* 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++;
if (!heartbeat_data->invert)
brightness = led_cdev->blink_brightness;
break;
case 1:
delay = heartbeat_data->period / 4 - msecs_to_jiffies(70);
heartbeat_data->phase++;
if (heartbeat_data->invert)
brightness = led_cdev->blink_brightness;
break;
case 2:
delay = msecs_to_jiffies(70);
heartbeat_data->phase++;
if (!heartbeat_data->invert)
brightness = led_cdev->blink_brightness;
break;
default:
delay = heartbeat_data->period - heartbeat_data->period / 4 -
msecs_to_jiffies(70);
heartbeat_data->phase = 0;
if (heartbeat_data->invert)
brightness = led_cdev->blink_brightness;
break;
}
led_set_brightness_nosleep(led_cdev, brightness);
mod_timer(&heartbeat_data->timer, jiffies + delay);
}
static ssize_t led_invert_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct heartbeat_trig_data *heartbeat_data =
led_trigger_get_drvdata(dev);
return sprintf(buf, "%u\n", heartbeat_data->invert);
}
static ssize_t led_invert_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t size)
{
struct heartbeat_trig_data *heartbeat_data =
led_trigger_get_drvdata(dev);
unsigned long state;
int ret;
ret = kstrtoul(buf, 0, &state);
if (ret)
return ret;
heartbeat_data->invert = !!state;
return size;
}
static DEVICE_ATTR(invert, 0644, led_invert_show, led_invert_store);
static struct attribute *heartbeat_trig_attrs[] = {
&dev_attr_invert.attr,
NULL
};
ATTRIBUTE_GROUPS(heartbeat_trig);
static int 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 -ENOMEM;
led_set_trigger_data(led_cdev, heartbeat_data);
heartbeat_data->led_cdev = led_cdev;
timer_setup(&heartbeat_data->timer, led_heartbeat_function, 0);
heartbeat_data->phase = 0;
if (!led_cdev->blink_brightness)
led_cdev->blink_brightness = led_cdev->max_brightness;
led_heartbeat_function(&heartbeat_data->timer);
set_bit(LED_BLINK_SW, &led_cdev->work_flags);
return 0;
}
static void heartbeat_trig_deactivate(struct led_classdev *led_cdev)
{
struct heartbeat_trig_data *heartbeat_data =
led_get_trigger_data(led_cdev);
del_timer_sync(&heartbeat_data->timer);
kfree(heartbeat_data);
clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
}
static struct led_trigger heartbeat_led_trigger = {
.name = "heartbeat",
.activate = heartbeat_trig_activate,
.deactivate = heartbeat_trig_deactivate,
.groups = heartbeat_trig_groups,
};
static int heartbeat_reboot_notifier(struct notifier_block *nb,
unsigned long code, void *unused)
{
led_trigger_unregister(&heartbeat_led_trigger);
return NOTIFY_DONE;
}
static int heartbeat_panic_notifier(struct notifier_block *nb,
unsigned long code, void *unused)
{
panic_heartbeats = 1;
return NOTIFY_DONE;
}
static struct notifier_block heartbeat_reboot_nb = {
.notifier_call = heartbeat_reboot_notifier,
};
static struct notifier_block heartbeat_panic_nb = {
.notifier_call = heartbeat_panic_notifier,
};
static int __init heartbeat_trig_init(void)
{
int rc = led_trigger_register(&heartbeat_led_trigger);
if (!rc) {
atomic_notifier_chain_register(&panic_notifier_list,
&heartbeat_panic_nb);
register_reboot_notifier(&heartbeat_reboot_nb);
}
return rc;
}
static void __exit heartbeat_trig_exit(void)
{
unregister_reboot_notifier(&heartbeat_reboot_nb);
atomic_notifier_chain_unregister(&panic_notifier_list,
&heartbeat_panic_nb);
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 v2");
|
