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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/sched/loadavg.h>
21#include <linux/leds.h>
22#include <linux/reboot.h>
23#include <linux/suspend.h>
24#include "../leds.h"
25
26static int panic_heartbeats;
27
28struct heartbeat_trig_data {
29 unsigned int phase;
30 unsigned int period;
31 struct timer_list timer;
32 unsigned int invert;
33};
34
35static void led_heartbeat_function(unsigned long data)
36{
37 struct led_classdev *led_cdev = (struct led_classdev *) data;
38 struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
39 unsigned long brightness = LED_OFF;
40 unsigned long delay = 0;
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 led_classdev *led_cdev = dev_get_drvdata(dev);
97 struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
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 led_classdev *led_cdev = dev_get_drvdata(dev);
106 struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
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 void heartbeat_trig_activate(struct led_classdev *led_cdev)
122{
123 struct heartbeat_trig_data *heartbeat_data;
124 int rc;
125
126 heartbeat_data = kzalloc(sizeof(*heartbeat_data), GFP_KERNEL);
127 if (!heartbeat_data)
128 return;
129
130 led_cdev->trigger_data = heartbeat_data;
131 rc = device_create_file(led_cdev->dev, &dev_attr_invert);
132 if (rc) {
133 kfree(led_cdev->trigger_data);
134 return;
135 }
136
137 setup_timer(&heartbeat_data->timer,
138 led_heartbeat_function, (unsigned long) led_cdev);
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.data);
143 set_bit(LED_BLINK_SW, &led_cdev->work_flags);
144 led_cdev->activated = true;
145}
146
147static void heartbeat_trig_deactivate(struct led_classdev *led_cdev)
148{
149 struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
150
151 if (led_cdev->activated) {
152 del_timer_sync(&heartbeat_data->timer);
153 device_remove_file(led_cdev->dev, &dev_attr_invert);
154 kfree(heartbeat_data);
155 clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
156 led_cdev->activated = false;
157 }
158}
159
160static struct led_trigger heartbeat_led_trigger = {
161 .name = "heartbeat",
162 .activate = heartbeat_trig_activate,
163 .deactivate = heartbeat_trig_deactivate,
164};
165
166static int heartbeat_pm_notifier(struct notifier_block *nb,
167 unsigned long pm_event, void *unused)
168{
169 int rc;
170
171 switch (pm_event) {
172 case PM_SUSPEND_PREPARE:
173 case PM_HIBERNATION_PREPARE:
174 case PM_RESTORE_PREPARE:
175 led_trigger_unregister(&heartbeat_led_trigger);
176 break;
177 case PM_POST_SUSPEND:
178 case PM_POST_HIBERNATION:
179 case PM_POST_RESTORE:
180 rc = led_trigger_register(&heartbeat_led_trigger);
181 if (rc)
182 pr_err("could not re-register heartbeat trigger\n");
183 break;
184 default:
185 break;
186 }
187 return NOTIFY_DONE;
188}
189
190static int heartbeat_reboot_notifier(struct notifier_block *nb,
191 unsigned long code, void *unused)
192{
193 led_trigger_unregister(&heartbeat_led_trigger);
194 return NOTIFY_DONE;
195}
196
197static int heartbeat_panic_notifier(struct notifier_block *nb,
198 unsigned long code, void *unused)
199{
200 panic_heartbeats = 1;
201 return NOTIFY_DONE;
202}
203
204static struct notifier_block heartbeat_pm_nb = {
205 .notifier_call = heartbeat_pm_notifier,
206};
207
208static struct notifier_block heartbeat_reboot_nb = {
209 .notifier_call = heartbeat_reboot_notifier,
210};
211
212static struct notifier_block heartbeat_panic_nb = {
213 .notifier_call = heartbeat_panic_notifier,
214};
215
216static int __init heartbeat_trig_init(void)
217{
218 int rc = led_trigger_register(&heartbeat_led_trigger);
219
220 if (!rc) {
221 atomic_notifier_chain_register(&panic_notifier_list,
222 &heartbeat_panic_nb);
223 register_reboot_notifier(&heartbeat_reboot_nb);
224 register_pm_notifier(&heartbeat_pm_nb);
225 }
226 return rc;
227}
228
229static void __exit heartbeat_trig_exit(void)
230{
231 unregister_pm_notifier(&heartbeat_pm_nb);
232 unregister_reboot_notifier(&heartbeat_reboot_nb);
233 atomic_notifier_chain_unregister(&panic_notifier_list,
234 &heartbeat_panic_nb);
235 led_trigger_unregister(&heartbeat_led_trigger);
236}
237
238module_init(heartbeat_trig_init);
239module_exit(heartbeat_trig_exit);
240
241MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
242MODULE_DESCRIPTION("Heartbeat LED trigger");
243MODULE_LICENSE("GPL");
244
