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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
52 switch (heartbeat_data->phase) {
53 case 0:
54
55
56
57
58
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 del_timer_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");
214
