1/*
2 * LED support for the input layer
3 *
4 * Copyright 2010-2015 Samuel Thibault <samuel.thibault@ens-lyon.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/kernel.h>
12#include <linux/slab.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/leds.h>
16#include <linux/input.h>
17
18#if IS_ENABLED(CONFIG_VT)
19#define VT_TRIGGER(_name) .trigger = _name
20#else
21#define VT_TRIGGER(_name) .trigger = NULL
22#endif
23
24static const struct {
25 const char *name;
26 const char *trigger;
27} input_led_info[LED_CNT] = {
28 [LED_NUML] = { "numlock", VT_TRIGGER("kbd-numlock") },
29 [LED_CAPSL] = { "capslock", VT_TRIGGER("kbd-capslock") },
30 [LED_SCROLLL] = { "scrolllock", VT_TRIGGER("kbd-scrolllock") },
31 [LED_COMPOSE] = { "compose" },
32 [LED_KANA] = { "kana", VT_TRIGGER("kbd-kanalock") },
33 [LED_SLEEP] = { "sleep" } ,
34 [LED_SUSPEND] = { "suspend" },
35 [LED_MUTE] = { "mute" },
36 [LED_MISC] = { "misc" },
37 [LED_MAIL] = { "mail" },
38 [LED_CHARGING] = { "charging" },
39};
40
41struct input_led {
42 struct led_classdev cdev;
43 struct input_handle *handle;
44 unsigned int code; /* One of LED_* constants */
45};
46
47struct input_leds {
48 struct input_handle handle;
49 unsigned int num_leds;
50 struct input_led leds[];
51};
52
53static enum led_brightness input_leds_brightness_get(struct led_classdev *cdev)
54{
55 struct input_led *led = container_of(cdev, struct input_led, cdev);
56 struct input_dev *input = led->handle->dev;
57
58 return test_bit(led->code, input->led) ? cdev->max_brightness : 0;
59}
60
61static void input_leds_brightness_set(struct led_classdev *cdev,
62 enum led_brightness brightness)
63{
64 struct input_led *led = container_of(cdev, struct input_led, cdev);
65
66 input_inject_event(led->handle, EV_LED, led->code, !!brightness);
67}
68
69static void input_leds_event(struct input_handle *handle, unsigned int type,
70 unsigned int code, int value)
71{
72}
73
74static int input_leds_get_count(struct input_dev *dev)
75{
76 unsigned int led_code;
77 int count = 0;
78
79 for_each_set_bit(led_code, dev->ledbit, LED_CNT)
80 if (input_led_info[led_code].name)
81 count++;
82
83 return count;
84}
85
86static int input_leds_connect(struct input_handler *handler,
87 struct input_dev *dev,
88 const struct input_device_id *id)
89{
90 struct input_leds *leds;
91 struct input_led *led;
92 unsigned int num_leds;
93 unsigned int led_code;
94 int led_no;
95 int error;
96
97 num_leds = input_leds_get_count(dev);
98 if (!num_leds)
99 return -ENXIO;
100
101 leds = kzalloc(struct_size(leds, leds, num_leds), GFP_KERNEL);
102 if (!leds)
103 return -ENOMEM;
104
105 leds->num_leds = num_leds;
106
107 leds->handle.dev = dev;
108 leds->handle.handler = handler;
109 leds->handle.name = "leds";
110 leds->handle.private = leds;
111
112 error = input_register_handle(&leds->handle);
113 if (error)
114 goto err_free_mem;
115
116 error = input_open_device(&leds->handle);
117 if (error)
118 goto err_unregister_handle;
119
120 led_no = 0;
121 for_each_set_bit(led_code, dev->ledbit, LED_CNT) {
122 if (!input_led_info[led_code].name)
123 continue;
124
125 led = &leds->leds[led_no];
126 led->handle = &leds->handle;
127 led->code = led_code;
128
129 led->cdev.name = kasprintf(GFP_KERNEL, "%s::%s",
130 dev_name(&dev->dev),
131 input_led_info[led_code].name);
132 if (!led->cdev.name) {
133 error = -ENOMEM;
134 goto err_unregister_leds;
135 }
136
137 led->cdev.max_brightness = 1;
138 led->cdev.brightness_get = input_leds_brightness_get;
139 led->cdev.brightness_set = input_leds_brightness_set;
140 led->cdev.default_trigger = input_led_info[led_code].trigger;
141
142 error = led_classdev_register(&dev->dev, &led->cdev);
143 if (error) {
144 dev_err(&dev->dev, "failed to register LED %s: %d\n",
145 led->cdev.name, error);
146 kfree(led->cdev.name);
147 goto err_unregister_leds;
148 }
149
150 led_no++;
151 }
152
153 return 0;
154
155err_unregister_leds:
156 while (--led_no >= 0) {
157 struct input_led *led = &leds->leds[led_no];
158
159 led_classdev_unregister(&led->cdev);
160 kfree(led->cdev.name);
161 }
162
163 input_close_device(&leds->handle);
164
165err_unregister_handle:
166 input_unregister_handle(&leds->handle);
167
168err_free_mem:
169 kfree(leds);
170 return error;
171}
172
173static void input_leds_disconnect(struct input_handle *handle)
174{
175 struct input_leds *leds = handle->private;
176 int i;
177
178 for (i = 0; i < leds->num_leds; i++) {
179 struct input_led *led = &leds->leds[i];
180
181 led_classdev_unregister(&led->cdev);
182 kfree(led->cdev.name);
183 }
184
185 input_close_device(handle);
186 input_unregister_handle(handle);
187
188 kfree(leds);
189}
190
191static const struct input_device_id input_leds_ids[] = {
192 {
193 .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
194 .evbit = { BIT_MASK(EV_LED) },
195 },
196 { },
197};
198MODULE_DEVICE_TABLE(input, input_leds_ids);
199
200static struct input_handler input_leds_handler = {
201 .event = input_leds_event,
202 .connect = input_leds_connect,
203 .disconnect = input_leds_disconnect,
204 .name = "leds",
205 .id_table = input_leds_ids,
206};
207
208static int __init input_leds_init(void)
209{
210 return input_register_handler(&input_leds_handler);
211}
212module_init(input_leds_init);
213
214static void __exit input_leds_exit(void)
215{
216 input_unregister_handler(&input_leds_handler);
217}
218module_exit(input_leds_exit);
219
220MODULE_AUTHOR("Samuel Thibault <samuel.thibault@ens-lyon.org>");
221MODULE_AUTHOR("Dmitry Torokhov <dmitry.torokhov@gmail.com>");
222MODULE_DESCRIPTION("Input -> LEDs Bridge");
223MODULE_LICENSE("GPL v2");
224