led.c 1.2 KB

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  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. #include <linux/module.h>
  8. #include <linux/kernel.h>
  9. #include <linux/init.h>
  10. #include <linux/leds.h>
  11. #include <linux/usb.h>
  12. #define BLINK_DELAY 30
  13. static unsigned long usb_blink_delay = BLINK_DELAY;
  14. DEFINE_LED_TRIGGER(ledtrig_usb_gadget);
  15. DEFINE_LED_TRIGGER(ledtrig_usb_host);
  16. void usb_led_activity(enum usb_led_event ev)
  17. {
  18. struct led_trigger *trig = NULL;
  19. switch (ev) {
  20. case USB_LED_EVENT_GADGET:
  21. trig = ledtrig_usb_gadget;
  22. break;
  23. case USB_LED_EVENT_HOST:
  24. trig = ledtrig_usb_host;
  25. break;
  26. }
  27. /* led_trigger_blink_oneshot() handles trig == NULL gracefully */
  28. led_trigger_blink_oneshot(trig, &usb_blink_delay, &usb_blink_delay, 0);
  29. }
  30. EXPORT_SYMBOL_GPL(usb_led_activity);
  31. static int __init ledtrig_usb_init(void)
  32. {
  33. led_trigger_register_simple("usb-gadget", &ledtrig_usb_gadget);
  34. led_trigger_register_simple("usb-host", &ledtrig_usb_host);
  35. return 0;
  36. }
  37. static void __exit ledtrig_usb_exit(void)
  38. {
  39. led_trigger_unregister_simple(ledtrig_usb_gadget);
  40. led_trigger_unregister_simple(ledtrig_usb_host);
  41. }
  42. module_init(ledtrig_usb_init);
  43. module_exit(ledtrig_usb_exit);