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 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 }