// SPDX-License-Identifier: GPL-2.0

/*
 * HID driver for WinWing Orion 2 throttle
 *
 * Copyright (c) 2023 Ivan Gorinov
 */

#include <linux/device.h>
#include <linux/hid.h>
#include <linux/hidraw.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>

#define MAX_REPORT 16

struct winwing_led {
        struct led_classdev cdev;
        struct hid_device *hdev;
        int number;
};

struct winwing_led_info {
        int number;
        int max_brightness;
        const char *led_name;
};

static const struct winwing_led_info led_info[3] = {
        { 0, 255, "backlight" },
        { 1, 1, "a-a" },
        { 2, 1, "a-g" },
};

struct winwing_drv_data {
        struct hid_device *hdev;
        __u8 *report_buf;
        struct mutex lock;
        int map_more_buttons;
        unsigned int num_leds;
        struct winwing_led leds[];
};

static int winwing_led_write(struct led_classdev *cdev,
                enum led_brightness br)
{
        struct winwing_led *led = (struct winwing_led *) cdev;
        struct winwing_drv_data *data = hid_get_drvdata(led->hdev);
        __u8 *buf = data->report_buf;
        int ret;

        mutex_lock(&data->lock);

        buf[0] = 0x02;
        buf[1] = 0x60;
        buf[2] = 0xbe;
        buf[3] = 0x00;
        buf[4] = 0x00;
        buf[5] = 0x03;
        buf[6] = 0x49;
        buf[7] = led->number;
        buf[8] = br;
        buf[9] = 0x00;
        buf[10] = 0;
        buf[11] = 0;
        buf[12] = 0;
        buf[13] = 0;

        ret = hid_hw_output_report(led->hdev, buf, 14);

        mutex_unlock(&data->lock);

        return ret;
}

static int winwing_init_led(struct hid_device *hdev,
                struct input_dev *input)
{
        struct winwing_drv_data *data;
        struct winwing_led *led;
        int ret;
        int i;

        data = hid_get_drvdata(hdev);

        if (!data)
                return -EINVAL;

        data->report_buf = devm_kmalloc(&hdev->dev, MAX_REPORT, GFP_KERNEL);

        if (!data->report_buf)
                return -ENOMEM;

        for (i = 0; i < 3; i += 1) {
                const struct winwing_led_info *info = &led_info[i];

                led = &data->leds[i];
                led->hdev = hdev;
                led->number = info->number;
                led->cdev.max_brightness = info->max_brightness;
                led->cdev.brightness_set_blocking = winwing_led_write;
                led->cdev.flags = LED_HW_PLUGGABLE;
                led->cdev.name = devm_kasprintf(&hdev->dev, GFP_KERNEL,
                                                "%s::%s",
                                                dev_name(&input->dev),
                                                info->led_name);

                if (!led->cdev.name)
                        return -ENOMEM;

                ret = devm_led_classdev_register(&hdev->dev, &led->cdev);
                if (ret)
                        return ret;
        }

        return ret;
}

static int winwing_map_button(int button, int map_more_buttons)
{
        if (button < 1)
                return KEY_RESERVED;

        if (button > 112)
                return KEY_RESERVED;

        if (button <= 16) {
                /*
                 * Grip buttons [1 .. 16] are mapped to
                 * key codes BTN_TRIGGER .. BTN_DEAD
                 */
                return (button - 1) + BTN_JOYSTICK;
        }

        if (button >= 65) {
                /*
                 * Base buttons [65 .. 112] are mapped to
                 * key codes BTN_TRIGGER_HAPPY17 .. KEY_MAX
                 */
                return (button - 65) + BTN_TRIGGER_HAPPY17;
        }

        if (!map_more_buttons) {
                /*
                 * Not mapping numbers [33 .. 64] which
                 * are not assigned to any real buttons
                 */
                if (button >= 33)
                        return KEY_RESERVED;
                /*
                 * Grip buttons [17 .. 32] are mapped to
                 * BTN_TRIGGER_HAPPY1 .. BTN_TRIGGER_HAPPY16
                 */
                return (button - 17) + BTN_TRIGGER_HAPPY1;
        }

        if (button >= 49) {
                /*
                 * Grip buttons [49 .. 64] are mapped to
                 * BTN_TRIGGER_HAPPY1 .. BTN_TRIGGER_HAPPY16
                 */
                return (button - 49) + BTN_TRIGGER_HAPPY1;
        }

        /*
         * Grip buttons [17 .. 44] are mapped to
         * key codes KEY_MACRO1 .. KEY_MACRO28;
         * also mapping numbers [45 .. 48] which
         * are not assigned to any real buttons.
         */
        return (button - 17) + KEY_MACRO1;
}

static int winwing_input_mapping(struct hid_device *hdev,
        struct hid_input *hi, struct hid_field *field, struct hid_usage *usage,
        unsigned long **bit, int *max)
{
        struct winwing_drv_data *data;
        int code = KEY_RESERVED;
        int button = 0;

        data = hid_get_drvdata(hdev);

        if (!data)
                return -EINVAL;

        if ((usage->hid & HID_USAGE_PAGE) != HID_UP_BUTTON)
                return 0;

        if (field->application != HID_GD_JOYSTICK)
                return 0;

        /* Button numbers start with 1 */
        button = usage->hid & HID_USAGE;

        code = winwing_map_button(button, data->map_more_buttons);

        hid_map_usage(hi, usage, bit, max, EV_KEY, code);

        return 1;
}

static int winwing_probe(struct hid_device *hdev,
                const struct hid_device_id *id)
{
        struct winwing_drv_data *data;
        size_t data_size = struct_size(data, leds, 3);
        int ret;

        ret = hid_parse(hdev);
        if (ret) {
                hid_err(hdev, "parse failed\n");
                return ret;
        }

        data = devm_kzalloc(&hdev->dev, data_size, GFP_KERNEL);

        if (!data)
                return -ENOMEM;

        data->map_more_buttons = id->driver_data;

        hid_set_drvdata(hdev, data);

        ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
        if (ret) {
                hid_err(hdev, "hw start failed\n");
                return ret;
        }

        return 0;
}

static int winwing_input_configured(struct hid_device *hdev,
                struct hid_input *hidinput)
{
        int ret;

        ret = winwing_init_led(hdev, hidinput->input);

        if (ret)
                hid_err(hdev, "led init failed\n");

        return ret;
}

static const struct hid_device_id winwing_devices[] = {
        { HID_USB_DEVICE(0x4098, 0xbd65), .driver_data = 1 },  /* TGRIP-15E  */
        { HID_USB_DEVICE(0x4098, 0xbd64), .driver_data = 1 },  /* TGRIP-15EX */
        { HID_USB_DEVICE(0x4098, 0xbe68), .driver_data = 0 },  /* TGRIP-16EX */
        { HID_USB_DEVICE(0x4098, 0xbe62), .driver_data = 0 },  /* TGRIP-18   */
        {}
};

MODULE_DEVICE_TABLE(hid, winwing_devices);

static struct hid_driver winwing_driver = {
        .name = "winwing",
        .id_table = winwing_devices,
        .input_configured = winwing_input_configured,
        .input_mapping = winwing_input_mapping,
        .probe = winwing_probe,
};
module_hid_driver(winwing_driver);

MODULE_DESCRIPTION("HID driver for WinWing Orion 2 throttle");
MODULE_LICENSE("GPL");