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
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 = _name
17 #else
18 #define VT_TRIGGER(_name) .trigger = NULL
19 #endif
20
21 #if IS_ENABLED(CONFIG_SND_CTL_LED)
22 #define AUDIO_TRIGGER(_name) .trigger = _name
23 #else
24 #define AUDIO_TRIGGER(_name) .trigger = NULL
25 #endif
26
27 static 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
44 struct input_led {
45 struct led_classdev cdev;
46 struct input_handle *handle;
47 unsigned int code; /* One of LED_* constants */
48 };
49
50 struct input_leds {
51 struct input_handle handle;
52 unsigned int num_leds;
53 struct input_led leds[] __counted_by(num_leds);
54 };
55
input_leds_brightness_get(struct led_classdev * cdev)56 static 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
input_leds_brightness_set(struct led_classdev * cdev,enum led_brightness brightness)64 static 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
input_leds_event(struct input_handle * handle,unsigned int type,unsigned int code,int value)72 static void input_leds_event(struct input_handle *handle, unsigned int type,
73 unsigned int code, int value)
74 {
75 }
76
input_leds_get_count(struct input_dev * dev)77 static 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
input_leds_connect(struct input_handler * handler,struct input_dev * dev,const struct input_device_id * id)89 static 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
158 err_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
168 err_unregister_handle:
169 input_unregister_handle(&leds->handle);
170
171 err_free_mem:
172 kfree(leds);
173 return error;
174 }
175
input_leds_disconnect(struct input_handle * handle)176 static 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
194 static 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 };
201 MODULE_DEVICE_TABLE(input, input_leds_ids);
202
203 static 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
input_leds_init(void)211 static int __init input_leds_init(void)
212 {
213 return input_register_handler(&input_leds_handler);
214 }
215 module_init(input_leds_init);
216
input_leds_exit(void)217 static void __exit input_leds_exit(void)
218 {
219 input_unregister_handler(&input_leds_handler);
220 }
221 module_exit(input_leds_exit);
222
223 MODULE_AUTHOR("Samuel Thibault <samuel.thibault@ens-lyon.org>");
224 MODULE_AUTHOR("Dmitry Torokhov <dmitry.torokhov@gmail.com>");
225 MODULE_DESCRIPTION("Input -> LEDs Bridge");
226 MODULE_LICENSE("GPL v2");
227