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 14 #define BLINK_DELAY 30 15 16 static unsigned long usb_blink_delay = BLINK_DELAY; 17 18 DEFINE_LED_TRIGGER(ledtrig_usb_gadget); 19 DEFINE_LED_TRIGGER(ledtrig_usb_host); 20 21 void usb_led_activity(enum usb_led_event ev) 22 { 23 struct led_trigger *trig = NULL; 24 25 switch (ev) { 26 case USB_LED_EVENT_GADGET: 27 trig = ledtrig_usb_gadget; 28 break; 29 case USB_LED_EVENT_HOST: 30 trig = ledtrig_usb_host; 31 break; 32 } 33 /* led_trigger_blink_oneshot() handles trig == NULL gracefully */ 34 led_trigger_blink_oneshot(trig, &usb_blink_delay, &usb_blink_delay, 0); 35 } 36 EXPORT_SYMBOL_GPL(usb_led_activity); 37 38 39 static int __init ledtrig_usb_init(void) 40 { 41 led_trigger_register_simple("usb-gadget", &ledtrig_usb_gadget); 42 led_trigger_register_simple("usb-host", &ledtrig_usb_host); 43 return 0; 44 } 45 46 static 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 52 module_init(ledtrig_usb_init); 53 module_exit(ledtrig_usb_exit); 54