1 // SPDX-License-Identifier: GPL-2.0
3 * Activity/power trigger
5 * Copyright (C) 2020 Raspberry Pi (Trading) Ltd.
7 * Based on Atsushi Nemoto's ledtrig-heartbeat.c, although there may be
8 * nothing left of the original now.
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/timer.h>
15 #include <linux/leds.h>
25 struct actpwr_trig_src {
32 struct led_classdev cdev;
33 struct actpwr_trig_data *parent;
34 enum led_brightness value;
35 unsigned int interval;
39 struct actpwr_trig_data {
40 struct led_trigger trig;
41 struct actpwr_vled virt_leds[TRIG_COUNT];
42 struct actpwr_vled *active;
43 struct timer_list timer;
47 static int actpwr_trig_activate(struct led_classdev *led_cdev);
48 static void actpwr_trig_deactivate(struct led_classdev *led_cdev);
50 static const struct actpwr_trig_src actpwr_trig_sources[TRIG_COUNT] = {
51 [TRIG_ACT] = { "mmc0", 500, true },
52 [TRIG_PWR] = { "default-on", 500, false },
55 static struct actpwr_trig_data actpwr_data = {
58 .activate = actpwr_trig_activate,
59 .deactivate = actpwr_trig_deactivate,
63 static void actpwr_brightness_set(struct led_classdev *led_cdev,
64 enum led_brightness value)
66 struct actpwr_vled *vled = container_of(led_cdev, struct actpwr_vled,
68 struct actpwr_trig_data *trig = vled->parent;
74 if (vled == trig->active)
75 led_trigger_event(&trig->trig, value);
78 static int actpwr_brightness_set_blocking(struct led_classdev *led_cdev,
79 enum led_brightness value)
81 actpwr_brightness_set(led_cdev, value);
85 static enum led_brightness actpwr_brightness_get(struct led_classdev *led_cdev)
87 struct actpwr_vled *vled = container_of(led_cdev, struct actpwr_vled,
93 static void actpwr_trig_cycle(struct timer_list *t)
95 struct actpwr_trig_data *trig = &actpwr_data;
96 struct actpwr_vled *active;
98 active = &trig->virt_leds[trig->next_active];
99 trig->active = active;
100 trig->next_active = (trig->next_active + 1) % TRIG_COUNT;
102 led_trigger_event(&trig->trig, active->value);
104 mod_timer(&trig->timer, jiffies + msecs_to_jiffies(active->interval));
107 static int actpwr_trig_activate(struct led_classdev *led_cdev)
109 struct actpwr_trig_data *trig = &actpwr_data;
111 /* Start the timer if this is the first LED */
113 actpwr_trig_cycle(&trig->timer);
115 led_set_brightness_nosleep(led_cdev, trig->active->value);
120 static void actpwr_trig_deactivate(struct led_classdev *led_cdev)
122 struct actpwr_trig_data *trig = &actpwr_data;
124 if (list_empty(&trig->trig.led_cdevs)) {
125 del_timer_sync(&trig->timer);
130 static int __init actpwr_trig_init(void)
132 struct actpwr_trig_data *trig = &actpwr_data;
136 timer_setup(&trig->timer, actpwr_trig_cycle, 0);
138 /* Register one "LED" for each source trigger */
139 for (i = 0; i < TRIG_COUNT; i++)
141 struct actpwr_vled *vled = &trig->virt_leds[i];
142 struct led_classdev *cdev = &vled->cdev;
143 const struct actpwr_trig_src *src = &actpwr_trig_sources[i];
146 vled->interval = src->interval;
147 vled->invert = src->invert;
148 cdev->name = src->name;
149 cdev->brightness_set = actpwr_brightness_set;
150 cdev->brightness_set_blocking = actpwr_brightness_set_blocking;
151 cdev->brightness_get = actpwr_brightness_get;
152 cdev->default_trigger = src->name;
153 ret = led_classdev_register(NULL, cdev);
158 ret = led_trigger_register(&trig->trig);
168 led_classdev_unregister(&trig->virt_leds[i].cdev);
174 static void __exit actpwr_trig_exit(void)
178 led_trigger_unregister(&actpwr_data.trig);
179 for (i = 0; i < TRIG_COUNT; i++)
181 led_classdev_unregister(&actpwr_data.virt_leds[i].cdev);
185 module_init(actpwr_trig_init);
186 module_exit(actpwr_trig_exit);
188 MODULE_AUTHOR("Phil Elwell <phil@raspberrypi.com>");
189 MODULE_DESCRIPTION("ACT/PWR LED trigger");
190 MODULE_LICENSE("GPL v2");