1// SPDX-License-Identifier: GPL-2.0
  2/* WMI driver for Xiaomi Laptops */
  3
  4#include <linux/acpi.h>
  5#include <linux/device.h>
  6#include <linux/input.h>
  7#include <linux/module.h>
  8#include <linux/mutex.h>
  9#include <linux/wmi.h>
 10
 11#include <uapi/linux/input-event-codes.h>
 12
 13#define XIAOMI_KEY_FN_ESC_0	"A2095CCE-0491-44E7-BA27-F8ED8F88AA86"
 14#define XIAOMI_KEY_FN_ESC_1	"7BBE8E39-B486-473D-BA13-66F75C5805CD"
 15#define XIAOMI_KEY_FN_FN	"409B028D-F06B-4C7C-8BBB-EE133A6BD87E"
 16#define XIAOMI_KEY_CAPSLOCK	"83FE7607-053A-4644-822A-21532C621FC7"
 17#define XIAOMI_KEY_FN_F7	"76E9027C-95D0-4180-8692-DA6747DD1C2D"
 18
 19#define XIAOMI_DEVICE(guid, key)		\
 20	.guid_string = (guid),			\
 21	.context = &(const unsigned int){key}
 22
 23struct xiaomi_wmi {
 24	struct input_dev *input_dev;
 25	struct mutex key_lock;	/* Protects the key event sequence */
 26	unsigned int key_code;
 27};
 28
 29static void xiaomi_mutex_destroy(void *data)
 30{
 31	struct mutex *lock = data;
 32
 33	mutex_destroy(lock);
 34}
 35
 36static int xiaomi_wmi_probe(struct wmi_device *wdev, const void *context)
 37{
 38	struct xiaomi_wmi *data;
 39	int ret;
 40
 41	if (wdev == NULL || context == NULL)
 42		return -EINVAL;
 43
 44	data = devm_kzalloc(&wdev->dev, sizeof(struct xiaomi_wmi), GFP_KERNEL);
 45	if (data == NULL)
 46		return -ENOMEM;
 47	dev_set_drvdata(&wdev->dev, data);
 48
 49	mutex_init(&data->key_lock);
 50	ret = devm_add_action_or_reset(&wdev->dev, xiaomi_mutex_destroy, &data->key_lock);
 51	if (ret < 0)
 52		return ret;
 53
 54	data->input_dev = devm_input_allocate_device(&wdev->dev);
 55	if (data->input_dev == NULL)
 56		return -ENOMEM;
 57	data->input_dev->name = "Xiaomi WMI keys";
 58	data->input_dev->phys = "wmi/input0";
 59
 60	data->key_code = *((const unsigned int *)context);
 61	set_bit(EV_KEY, data->input_dev->evbit);
 62	set_bit(data->key_code, data->input_dev->keybit);
 63
 64	return input_register_device(data->input_dev);
 65}
 66
 67static void xiaomi_wmi_notify(struct wmi_device *wdev, union acpi_object *dummy)
 68{
 69	struct xiaomi_wmi *data;
 70
 71	if (wdev == NULL)
 72		return;
 73
 74	data = dev_get_drvdata(&wdev->dev);
 75	if (data == NULL)
 76		return;
 77
 78	mutex_lock(&data->key_lock);
 79	input_report_key(data->input_dev, data->key_code, 1);
 80	input_sync(data->input_dev);
 81	input_report_key(data->input_dev, data->key_code, 0);
 82	input_sync(data->input_dev);
 83	mutex_unlock(&data->key_lock);
 84}
 85
 86static const struct wmi_device_id xiaomi_wmi_id_table[] = {
 87	// { XIAOMI_DEVICE(XIAOMI_KEY_FN_ESC_0, KEY_FN_ESC) },
 88	// { XIAOMI_DEVICE(XIAOMI_KEY_FN_ESC_1, KEY_FN_ESC) },
 89	{ XIAOMI_DEVICE(XIAOMI_KEY_FN_FN, KEY_PROG1) },
 90	// { XIAOMI_DEVICE(XIAOMI_KEY_CAPSLOCK, KEY_CAPSLOCK) },
 91	{ XIAOMI_DEVICE(XIAOMI_KEY_FN_F7, KEY_CUT) },
 92
 93	/* Terminating entry */
 94	{ }
 95};
 96
 97static struct wmi_driver xiaomi_wmi_driver = {
 98	.driver = {
 99		.name = "xiaomi-wmi",
100	},
101	.id_table = xiaomi_wmi_id_table,
102	.probe = xiaomi_wmi_probe,
103	.notify = xiaomi_wmi_notify,
104};
105module_wmi_driver(xiaomi_wmi_driver);
106
107MODULE_DEVICE_TABLE(wmi, xiaomi_wmi_id_table);
108MODULE_AUTHOR("Mattias Jacobsson");
109MODULE_DESCRIPTION("Xiaomi WMI driver");
110MODULE_LICENSE("GPL v2");