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
17DEFINE_LED_TRIGGER(ledtrig_usb_gadget);
18DEFINE_LED_TRIGGER(ledtrig_usb_host);
19
20void usb_led_activity(enum usb_led_event ev)
21{
22 struct led_trigger *trig = NULL;
23
24 switch (ev) {
25 case USB_LED_EVENT_GADGET:
26 trig = ledtrig_usb_gadget;
27 break;
28 case USB_LED_EVENT_HOST:
29 trig = ledtrig_usb_host;
30 break;
31 }
32 /* led_trigger_blink_oneshot() handles trig == NULL gracefully */
33 led_trigger_blink_oneshot(trigger: trig, BLINK_DELAY, BLINK_DELAY, invert: 0);
34}
35EXPORT_SYMBOL_GPL(usb_led_activity);
36
37
38void __init ledtrig_usb_init(void)
39{
40 led_trigger_register_simple(name: "usb-gadget", trigger: &ledtrig_usb_gadget);
41 led_trigger_register_simple(name: "usb-host", trigger: &ledtrig_usb_host);
42}
43
44void __exit ledtrig_usb_exit(void)
45{
46 led_trigger_unregister_simple(trigger: ledtrig_usb_gadget);
47 led_trigger_unregister_simple(trigger: ledtrig_usb_host);
48}
49

source code of linux/drivers/usb/common/led.c