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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * LED support for the input layer4 *5 * Copyright 2010-2015 Samuel Thibault <samuel.thibault@ens-lyon.org>6 */7 8#include <linux/kernel.h>9#include <linux/slab.h>10#include <linux/module.h>11#include <linux/init.h>12#include <linux/leds.h>13#include <linux/input.h>14 15#if IS_ENABLED(CONFIG_VT)16#define VT_TRIGGER(_name) .trigger = _name17#else18#define VT_TRIGGER(_name) .trigger = NULL19#endif20 21#if IS_ENABLED(CONFIG_SND_CTL_LED)22#define AUDIO_TRIGGER(_name) .trigger = _name23#else24#define AUDIO_TRIGGER(_name) .trigger = NULL25#endif26 27static const struct {28 const char *name;29 const char *trigger;30} input_led_info[LED_CNT] = {31 [LED_NUML] = { "numlock", VT_TRIGGER("kbd-numlock") },32 [LED_CAPSL] = { "capslock", VT_TRIGGER("kbd-capslock") },33 [LED_SCROLLL] = { "scrolllock", VT_TRIGGER("kbd-scrolllock") },34 [LED_COMPOSE] = { "compose" },35 [LED_KANA] = { "kana", VT_TRIGGER("kbd-kanalock") },36 [LED_SLEEP] = { "sleep" } ,37 [LED_SUSPEND] = { "suspend" },38 [LED_MUTE] = { "mute", AUDIO_TRIGGER("audio-mute") },39 [LED_MISC] = { "misc" },40 [LED_MAIL] = { "mail" },41 [LED_CHARGING] = { "charging" },42};43 44struct input_led {45 struct led_classdev cdev;46 struct input_handle *handle;47 unsigned int code; /* One of LED_* constants */48};49 50struct input_leds {51 struct input_handle handle;52 unsigned int num_leds;53 struct input_led leds[] __counted_by(num_leds);54};55 56static enum led_brightness input_leds_brightness_get(struct led_classdev *cdev)57{58 struct input_led *led = container_of(cdev, struct input_led, cdev);59 struct input_dev *input = led->handle->dev;60 61 return test_bit(led->code, input->led) ? cdev->max_brightness : 0;62}63 64static void input_leds_brightness_set(struct led_classdev *cdev,65 enum led_brightness brightness)66{67 struct input_led *led = container_of(cdev, struct input_led, cdev);68 69 input_inject_event(led->handle, EV_LED, led->code, !!brightness);70}71 72static void input_leds_event(struct input_handle *handle, unsigned int type,73 unsigned int code, int value)74{75}76 77static int input_leds_get_count(struct input_dev *dev)78{79 unsigned int led_code;80 int count = 0;81 82 for_each_set_bit(led_code, dev->ledbit, LED_CNT)83 if (input_led_info[led_code].name)84 count++;85 86 return count;87}88 89static int input_leds_connect(struct input_handler *handler,90 struct input_dev *dev,91 const struct input_device_id *id)92{93 struct input_leds *leds;94 struct input_led *led;95 unsigned int num_leds;96 unsigned int led_code;97 int led_no;98 int error;99 100 num_leds = input_leds_get_count(dev);101 if (!num_leds)102 return -ENXIO;103 104 leds = kzalloc(struct_size(leds, leds, num_leds), GFP_KERNEL);105 if (!leds)106 return -ENOMEM;107 108 leds->num_leds = num_leds;109 110 leds->handle.dev = dev;111 leds->handle.handler = handler;112 leds->handle.name = "leds";113 leds->handle.private = leds;114 115 error = input_register_handle(&leds->handle);116 if (error)117 goto err_free_mem;118 119 error = input_open_device(&leds->handle);120 if (error)121 goto err_unregister_handle;122 123 led_no = 0;124 for_each_set_bit(led_code, dev->ledbit, LED_CNT) {125 if (!input_led_info[led_code].name)126 continue;127 128 led = &leds->leds[led_no];129 led->handle = &leds->handle;130 led->code = led_code;131 132 led->cdev.name = kasprintf(GFP_KERNEL, "%s::%s",133 dev_name(&dev->dev),134 input_led_info[led_code].name);135 if (!led->cdev.name) {136 error = -ENOMEM;137 goto err_unregister_leds;138 }139 140 led->cdev.max_brightness = 1;141 led->cdev.brightness_get = input_leds_brightness_get;142 led->cdev.brightness_set = input_leds_brightness_set;143 led->cdev.default_trigger = input_led_info[led_code].trigger;144 145 error = led_classdev_register(&dev->dev, &led->cdev);146 if (error) {147 dev_err(&dev->dev, "failed to register LED %s: %d\n",148 led->cdev.name, error);149 kfree(led->cdev.name);150 goto err_unregister_leds;151 }152 153 led_no++;154 }155 156 return 0;157 158err_unregister_leds:159 while (--led_no >= 0) {160 struct input_led *led = &leds->leds[led_no];161 162 led_classdev_unregister(&led->cdev);163 kfree(led->cdev.name);164 }165 166 input_close_device(&leds->handle);167 168err_unregister_handle:169 input_unregister_handle(&leds->handle);170 171err_free_mem:172 kfree(leds);173 return error;174}175 176static void input_leds_disconnect(struct input_handle *handle)177{178 struct input_leds *leds = handle->private;179 int i;180 181 for (i = 0; i < leds->num_leds; i++) {182 struct input_led *led = &leds->leds[i];183 184 led_classdev_unregister(&led->cdev);185 kfree(led->cdev.name);186 }187 188 input_close_device(handle);189 input_unregister_handle(handle);190 191 kfree(leds);192}193 194static const struct input_device_id input_leds_ids[] = {195 {196 .flags = INPUT_DEVICE_ID_MATCH_EVBIT,197 .evbit = { BIT_MASK(EV_LED) },198 },199 { },200};201MODULE_DEVICE_TABLE(input, input_leds_ids);202 203static struct input_handler input_leds_handler = {204 .event = input_leds_event,205 .connect = input_leds_connect,206 .disconnect = input_leds_disconnect,207 .name = "leds",208 .id_table = input_leds_ids,209};210 211static int __init input_leds_init(void)212{213 return input_register_handler(&input_leds_handler);214}215module_init(input_leds_init);216 217static void __exit input_leds_exit(void)218{219 input_unregister_handler(&input_leds_handler);220}221module_exit(input_leds_exit);222 223MODULE_AUTHOR("Samuel Thibault <samuel.thibault@ens-lyon.org>");224MODULE_AUTHOR("Dmitry Torokhov <dmitry.torokhov@gmail.com>");225MODULE_DESCRIPTION("Input -> LEDs Bridge");226MODULE_LICENSE("GPL v2");227