linux/drivers/input/input-leds.c

225 lines
5.2 KiB
C

/*
* LED support for the input layer
*
* Copyright 2010-2015 Samuel Thibault <samuel.thibault@ens-lyon.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/leds.h>
#include <linux/input.h>
#if IS_ENABLED(CONFIG_VT)
#define VT_TRIGGER(_name) .trigger = _name
#else
#define VT_TRIGGER(_name) .trigger = NULL
#endif
static const struct {
const char *name;
const char *trigger;
} input_led_info[LED_CNT] = {
[LED_NUML] = { "numlock", VT_TRIGGER("kbd-numlock") },
[LED_CAPSL] = { "capslock", VT_TRIGGER("kbd-capslock") },
[LED_SCROLLL] = { "scrolllock", VT_TRIGGER("kbd-scrolllock") },
[LED_COMPOSE] = { "compose" },
[LED_KANA] = { "kana", VT_TRIGGER("kbd-kanalock") },
[LED_SLEEP] = { "sleep" } ,
[LED_SUSPEND] = { "suspend" },
[LED_MUTE] = { "mute" },
[LED_MISC] = { "misc" },
[LED_MAIL] = { "mail" },
[LED_CHARGING] = { "charging" },
};
struct input_led {
struct led_classdev cdev;
struct input_handle *handle;
unsigned int code; /* One of LED_* constants */
};
struct input_leds {
struct input_handle handle;
unsigned int num_leds;
struct input_led leds[];
};
static enum led_brightness input_leds_brightness_get(struct led_classdev *cdev)
{
struct input_led *led = container_of(cdev, struct input_led, cdev);
struct input_dev *input = led->handle->dev;
return test_bit(led->code, input->led) ? cdev->max_brightness : 0;
}
static void input_leds_brightness_set(struct led_classdev *cdev,
enum led_brightness brightness)
{
struct input_led *led = container_of(cdev, struct input_led, cdev);
input_inject_event(led->handle, EV_LED, led->code, !!brightness);
}
static void input_leds_event(struct input_handle *handle, unsigned int type,
unsigned int code, int value)
{
}
static int input_leds_get_count(struct input_dev *dev)
{
unsigned int led_code;
int count = 0;
for_each_set_bit(led_code, dev->ledbit, LED_CNT)
if (input_led_info[led_code].name)
count++;
return count;
}
static int input_leds_connect(struct input_handler *handler,
struct input_dev *dev,
const struct input_device_id *id)
{
struct input_leds *leds;
unsigned int num_leds;
unsigned int led_code;
int led_no;
int error;
num_leds = input_leds_get_count(dev);
if (!num_leds)
return -ENXIO;
leds = kzalloc(sizeof(*leds) + num_leds * sizeof(*leds->leds),
GFP_KERNEL);
if (!leds)
return -ENOMEM;
leds->num_leds = num_leds;
leds->handle.dev = dev;
leds->handle.handler = handler;
leds->handle.name = "leds";
leds->handle.private = leds;
error = input_register_handle(&leds->handle);
if (error)
goto err_free_mem;
error = input_open_device(&leds->handle);
if (error)
goto err_unregister_handle;
led_no = 0;
for_each_set_bit(led_code, dev->ledbit, LED_CNT) {
struct input_led *led = &leds->leds[led_no];
led->handle = &leds->handle;
led->code = led_code;
if (!input_led_info[led_code].name)
continue;
led->cdev.name = kasprintf(GFP_KERNEL, "%s::%s",
dev_name(&dev->dev),
input_led_info[led_code].name);
if (!led->cdev.name) {
error = -ENOMEM;
goto err_unregister_leds;
}
led->cdev.max_brightness = 1;
led->cdev.brightness_get = input_leds_brightness_get;
led->cdev.brightness_set = input_leds_brightness_set;
led->cdev.default_trigger = input_led_info[led_code].trigger;
error = led_classdev_register(&dev->dev, &led->cdev);
if (error) {
dev_err(&dev->dev, "failed to register LED %s: %d\n",
led->cdev.name, error);
kfree(led->cdev.name);
goto err_unregister_leds;
}
led_no++;
}
return 0;
err_unregister_leds:
while (--led_no >= 0) {
struct input_led *led = &leds->leds[led_no];
led_classdev_unregister(&led->cdev);
kfree(led->cdev.name);
}
input_close_device(&leds->handle);
err_unregister_handle:
input_unregister_handle(&leds->handle);
err_free_mem:
kfree(leds);
return error;
}
static void input_leds_disconnect(struct input_handle *handle)
{
struct input_leds *leds = handle->private;
int i;
for (i = 0; i < leds->num_leds; i++) {
struct input_led *led = &leds->leds[i];
led_classdev_unregister(&led->cdev);
kfree(led->cdev.name);
}
input_close_device(handle);
input_unregister_handle(handle);
kfree(leds);
}
static const struct input_device_id input_leds_ids[] = {
{
.flags = INPUT_DEVICE_ID_MATCH_EVBIT,
.evbit = { BIT_MASK(EV_LED) },
},
{ },
};
MODULE_DEVICE_TABLE(input, input_leds_ids);
static struct input_handler input_leds_handler = {
.event = input_leds_event,
.connect = input_leds_connect,
.disconnect = input_leds_disconnect,
.name = "leds",
.id_table = input_leds_ids,
};
static int __init input_leds_init(void)
{
return input_register_handler(&input_leds_handler);
}
module_init(input_leds_init);
static void __exit input_leds_exit(void)
{
input_unregister_handler(&input_leds_handler);
}
module_exit(input_leds_exit);
MODULE_AUTHOR("Samuel Thibault <samuel.thibault@ens-lyon.org>");
MODULE_AUTHOR("Dmitry Torokhov <dmitry.torokhov@gmail.com>");
MODULE_DESCRIPTION("Input -> LEDs Bridge");
MODULE_LICENSE("GPL v2");