input-leds.c 5.0 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * LED support for the input layer
  4. *
  5. * Copyright 2010-2015 Samuel Thibault <samuel.thibault@ens-lyon.org>
  6. */
  7. #include <linux/kernel.h>
  8. #include <linux/slab.h>
  9. #include <linux/module.h>
  10. #include <linux/init.h>
  11. #include <linux/leds.h>
  12. #include <linux/input.h>
  13. #if IS_ENABLED(CONFIG_VT)
  14. #define VT_TRIGGER(_name) .trigger = _name
  15. #else
  16. #define VT_TRIGGER(_name) .trigger = NULL
  17. #endif
  18. static const struct {
  19. const char *name;
  20. const char *trigger;
  21. } input_led_info[LED_CNT] = {
  22. [LED_NUML] = { "numlock", VT_TRIGGER("kbd-numlock") },
  23. [LED_CAPSL] = { "capslock", VT_TRIGGER("kbd-capslock") },
  24. [LED_SCROLLL] = { "scrolllock", VT_TRIGGER("kbd-scrolllock") },
  25. [LED_COMPOSE] = { "compose" },
  26. [LED_KANA] = { "kana", VT_TRIGGER("kbd-kanalock") },
  27. [LED_SLEEP] = { "sleep" } ,
  28. [LED_SUSPEND] = { "suspend" },
  29. [LED_MUTE] = { "mute" },
  30. [LED_MISC] = { "misc" },
  31. [LED_MAIL] = { "mail" },
  32. [LED_CHARGING] = { "charging" },
  33. };
  34. struct input_led {
  35. struct led_classdev cdev;
  36. struct input_handle *handle;
  37. unsigned int code; /* One of LED_* constants */
  38. };
  39. struct input_leds {
  40. struct input_handle handle;
  41. unsigned int num_leds;
  42. struct input_led leds[];
  43. };
  44. static enum led_brightness input_leds_brightness_get(struct led_classdev *cdev)
  45. {
  46. struct input_led *led = container_of(cdev, struct input_led, cdev);
  47. struct input_dev *input = led->handle->dev;
  48. return test_bit(led->code, input->led) ? cdev->max_brightness : 0;
  49. }
  50. static void input_leds_brightness_set(struct led_classdev *cdev,
  51. enum led_brightness brightness)
  52. {
  53. struct input_led *led = container_of(cdev, struct input_led, cdev);
  54. input_inject_event(led->handle, EV_LED, led->code, !!brightness);
  55. }
  56. static void input_leds_event(struct input_handle *handle, unsigned int type,
  57. unsigned int code, int value)
  58. {
  59. }
  60. static int input_leds_get_count(struct input_dev *dev)
  61. {
  62. unsigned int led_code;
  63. int count = 0;
  64. for_each_set_bit(led_code, dev->ledbit, LED_CNT)
  65. if (input_led_info[led_code].name)
  66. count++;
  67. return count;
  68. }
  69. static int input_leds_connect(struct input_handler *handler,
  70. struct input_dev *dev,
  71. const struct input_device_id *id)
  72. {
  73. struct input_leds *leds;
  74. struct input_led *led;
  75. unsigned int num_leds;
  76. unsigned int led_code;
  77. int led_no;
  78. int error;
  79. num_leds = input_leds_get_count(dev);
  80. if (!num_leds)
  81. return -ENXIO;
  82. leds = kzalloc(struct_size(leds, leds, num_leds), GFP_KERNEL);
  83. if (!leds)
  84. return -ENOMEM;
  85. leds->num_leds = num_leds;
  86. leds->handle.dev = dev;
  87. leds->handle.handler = handler;
  88. leds->handle.name = "leds";
  89. leds->handle.private = leds;
  90. error = input_register_handle(&leds->handle);
  91. if (error)
  92. goto err_free_mem;
  93. error = input_open_device(&leds->handle);
  94. if (error)
  95. goto err_unregister_handle;
  96. led_no = 0;
  97. for_each_set_bit(led_code, dev->ledbit, LED_CNT) {
  98. if (!input_led_info[led_code].name)
  99. continue;
  100. led = &leds->leds[led_no];
  101. led->handle = &leds->handle;
  102. led->code = led_code;
  103. led->cdev.name = kasprintf(GFP_KERNEL, "%s::%s",
  104. dev_name(&dev->dev),
  105. input_led_info[led_code].name);
  106. if (!led->cdev.name) {
  107. error = -ENOMEM;
  108. goto err_unregister_leds;
  109. }
  110. led->cdev.max_brightness = 1;
  111. led->cdev.brightness_get = input_leds_brightness_get;
  112. led->cdev.brightness_set = input_leds_brightness_set;
  113. led->cdev.default_trigger = input_led_info[led_code].trigger;
  114. error = led_classdev_register(&dev->dev, &led->cdev);
  115. if (error) {
  116. dev_err(&dev->dev, "failed to register LED %s: %d\n",
  117. led->cdev.name, error);
  118. kfree(led->cdev.name);
  119. goto err_unregister_leds;
  120. }
  121. led_no++;
  122. }
  123. return 0;
  124. err_unregister_leds:
  125. while (--led_no >= 0) {
  126. struct input_led *led = &leds->leds[led_no];
  127. led_classdev_unregister(&led->cdev);
  128. kfree(led->cdev.name);
  129. }
  130. input_close_device(&leds->handle);
  131. err_unregister_handle:
  132. input_unregister_handle(&leds->handle);
  133. err_free_mem:
  134. kfree(leds);
  135. return error;
  136. }
  137. static void input_leds_disconnect(struct input_handle *handle)
  138. {
  139. struct input_leds *leds = handle->private;
  140. int i;
  141. for (i = 0; i < leds->num_leds; i++) {
  142. struct input_led *led = &leds->leds[i];
  143. led_classdev_unregister(&led->cdev);
  144. kfree(led->cdev.name);
  145. }
  146. input_close_device(handle);
  147. input_unregister_handle(handle);
  148. kfree(leds);
  149. }
  150. static const struct input_device_id input_leds_ids[] = {
  151. {
  152. .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
  153. .evbit = { BIT_MASK(EV_LED) },
  154. },
  155. { },
  156. };
  157. MODULE_DEVICE_TABLE(input, input_leds_ids);
  158. static struct input_handler input_leds_handler = {
  159. .event = input_leds_event,
  160. .connect = input_leds_connect,
  161. .disconnect = input_leds_disconnect,
  162. .name = "leds",
  163. .id_table = input_leds_ids,
  164. };
  165. static int __init input_leds_init(void)
  166. {
  167. return input_register_handler(&input_leds_handler);
  168. }
  169. module_init(input_leds_init);
  170. static void __exit input_leds_exit(void)
  171. {
  172. input_unregister_handler(&input_leds_handler);
  173. }
  174. module_exit(input_leds_exit);
  175. MODULE_AUTHOR("Samuel Thibault <samuel.thibault@ens-lyon.org>");
  176. MODULE_AUTHOR("Dmitry Torokhov <dmitry.torokhov@gmail.com>");
  177. MODULE_DESCRIPTION("Input -> LEDs Bridge");
  178. MODULE_LICENSE("GPL v2");