xref: /openbmc/linux/drivers/usb/common/led.c (revision e65e175b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * LED Triggers for USB Activity
4  *
5  * Copyright 2014 Michal Sojka <sojka@merica.cz>
6  */
7 
8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/leds.h>
12 #include <linux/usb.h>
13 #include "common.h"
14 
15 #define BLINK_DELAY 30
16 
17 static unsigned long usb_blink_delay = BLINK_DELAY;
18 
19 DEFINE_LED_TRIGGER(ledtrig_usb_gadget);
20 DEFINE_LED_TRIGGER(ledtrig_usb_host);
21 
22 void usb_led_activity(enum usb_led_event ev)
23 {
24 	struct led_trigger *trig = NULL;
25 
26 	switch (ev) {
27 	case USB_LED_EVENT_GADGET:
28 		trig = ledtrig_usb_gadget;
29 		break;
30 	case USB_LED_EVENT_HOST:
31 		trig = ledtrig_usb_host;
32 		break;
33 	}
34 	/* led_trigger_blink_oneshot() handles trig == NULL gracefully */
35 	led_trigger_blink_oneshot(trig, &usb_blink_delay, &usb_blink_delay, 0);
36 }
37 EXPORT_SYMBOL_GPL(usb_led_activity);
38 
39 
40 void __init ledtrig_usb_init(void)
41 {
42 	led_trigger_register_simple("usb-gadget", &ledtrig_usb_gadget);
43 	led_trigger_register_simple("usb-host", &ledtrig_usb_host);
44 }
45 
46 void __exit ledtrig_usb_exit(void)
47 {
48 	led_trigger_unregister_simple(ledtrig_usb_gadget);
49 	led_trigger_unregister_simple(ledtrig_usb_host);
50 }
51