// SPDX-License-Identifier: GPL-2.0
/* WMI driver for Xiaomi Laptops */

#include <linux/device.h>
#include <linux/input.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/wmi.h>

#include <uapi/linux/input-event-codes.h>

#define XIAOMI_KEY_FN_ESC_0     "A2095CCE-0491-44E7-BA27-F8ED8F88AA86"
#define XIAOMI_KEY_FN_ESC_1     "7BBE8E39-B486-473D-BA13-66F75C5805CD"
#define XIAOMI_KEY_FN_FN        "409B028D-F06B-4C7C-8BBB-EE133A6BD87E"
#define XIAOMI_KEY_CAPSLOCK     "83FE7607-053A-4644-822A-21532C621FC7"
#define XIAOMI_KEY_FN_F7        "76E9027C-95D0-4180-8692-DA6747DD1C2D"

#define XIAOMI_DEVICE(guid, key)                \
        .guid_string = (guid),                  \
        .context = &(const unsigned int){key}

struct xiaomi_wmi {
        struct input_dev *input_dev;
        struct mutex key_lock;  /* Protects the key event sequence */
        unsigned int key_code;
};

static int xiaomi_wmi_probe(struct wmi_device *wdev, const void *context)
{
        struct xiaomi_wmi *data;
        int ret;

        if (!context)
                return -EINVAL;

        data = devm_kzalloc(&wdev->dev, sizeof(struct xiaomi_wmi), GFP_KERNEL);
        if (data == NULL)
                return -ENOMEM;
        dev_set_drvdata(&wdev->dev, data);

        ret = devm_mutex_init(&wdev->dev, &data->key_lock);
        if (ret < 0)
                return ret;

        data->input_dev = devm_input_allocate_device(&wdev->dev);
        if (data->input_dev == NULL)
                return -ENOMEM;
        data->input_dev->name = "Xiaomi WMI keys";
        data->input_dev->phys = "wmi/input0";

        data->key_code = *((const unsigned int *)context);
        set_bit(EV_KEY, data->input_dev->evbit);
        set_bit(data->key_code, data->input_dev->keybit);

        return input_register_device(data->input_dev);
}

static void xiaomi_wmi_notify(struct wmi_device *wdev, const struct wmi_buffer *dummy)
{
        struct xiaomi_wmi *data = dev_get_drvdata(&wdev->dev);

        mutex_lock(&data->key_lock);
        input_report_key(data->input_dev, data->key_code, 1);
        input_sync(data->input_dev);
        input_report_key(data->input_dev, data->key_code, 0);
        input_sync(data->input_dev);
        mutex_unlock(&data->key_lock);
}

static const struct wmi_device_id xiaomi_wmi_id_table[] = {
        // { XIAOMI_DEVICE(XIAOMI_KEY_FN_ESC_0, KEY_FN_ESC) },
        // { XIAOMI_DEVICE(XIAOMI_KEY_FN_ESC_1, KEY_FN_ESC) },
        { XIAOMI_DEVICE(XIAOMI_KEY_FN_FN, KEY_PROG1) },
        // { XIAOMI_DEVICE(XIAOMI_KEY_CAPSLOCK, KEY_CAPSLOCK) },
        { XIAOMI_DEVICE(XIAOMI_KEY_FN_F7, KEY_CUT) },

        /* Terminating entry */
        { }
};

static struct wmi_driver xiaomi_wmi_driver = {
        .driver = {
                .name = "xiaomi-wmi",
        },
        .id_table = xiaomi_wmi_id_table,
        .probe = xiaomi_wmi_probe,
        .notify_new = xiaomi_wmi_notify,
        .no_singleton = true,
};
module_wmi_driver(xiaomi_wmi_driver);

MODULE_DEVICE_TABLE(wmi, xiaomi_wmi_id_table);
MODULE_AUTHOR("Mattias Jacobsson");
MODULE_DESCRIPTION("Xiaomi WMI driver");
MODULE_LICENSE("GPL v2");