drivers/usb/common/led.c

   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 DEFINE_LED_TRIGGER(ledtrig_usb_gadget);
  18 DEFINE_LED_TRIGGER(ledtrig_usb_host);
  19
  20 void 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(trig, BLINK_DELAY, BLINK_DELAY, 0);
  34 }
  35 EXPORT_SYMBOL_GPL(usb_led_activity);
  36
  37
  38 void __init ledtrig_usb_init(void)
  39 {
  40         led_trigger_register_simple("usb-gadget", &ledtrig_usb_gadget);
  41         led_trigger_register_simple("usb-host", &ledtrig_usb_host);
  42 }
  43
  44 void __exit ledtrig_usb_exit(void)
  45 {
  46         led_trigger_unregister_simple(ledtrig_usb_gadget);
  47         led_trigger_unregister_simple(ledtrig_usb_host);
  48 }