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