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 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 */ 12 13 #include <linux/module.h> 14 #include <linux/kernel.h> 15 #include <linux/init.h> 16 #include <linux/leds.h> 17 #include <linux/usb.h> 18 19 #define BLINK_DELAY 30 20 21 static unsigned long usb_blink_delay = BLINK_DELAY; 22 23 DEFINE_LED_TRIGGER(ledtrig_usb_gadget); 24 DEFINE_LED_TRIGGER(ledtrig_usb_host); 25 26 void usb_led_activity(enum usb_led_event ev) 27 { 28 struct led_trigger *trig = NULL; 29 30 switch (ev) { 31 case USB_LED_EVENT_GADGET: 32 trig = ledtrig_usb_gadget; 33 break; 34 case USB_LED_EVENT_HOST: 35 trig = ledtrig_usb_host; 36 break; 37 } 38 /* led_trigger_blink_oneshot() handles trig == NULL gracefully */ 39 led_trigger_blink_oneshot(trig, &usb_blink_delay, &usb_blink_delay, 0); 40 } 41 EXPORT_SYMBOL_GPL(usb_led_activity); 42 43 44 static int __init ledtrig_usb_init(void) 45 { 46 led_trigger_register_simple("usb-gadget", &ledtrig_usb_gadget); 47 led_trigger_register_simple("usb-host", &ledtrig_usb_host); 48 return 0; 49 } 50 51 static void __exit ledtrig_usb_exit(void) 52 { 53 led_trigger_unregister_simple(ledtrig_usb_gadget); 54 led_trigger_unregister_simple(ledtrig_usb_host); 55 } 56 57 module_init(ledtrig_usb_init); 58 module_exit(ledtrig_usb_exit); 59