// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * HID driver for VRC-2 2-axis Car controller
 *
 * Copyright (C) 2022 Marcus Folkesson <marcus.folkesson@gmail.com>
 */

#include <linux/device.h>
#include <linux/hid.h>
#include <linux/module.h>

/*
 * VID/PID are probably "borrowed", so keep them locally and
 * do not populate hid-ids.h with those.
 */
#define USB_VENDOR_ID_VRC2      (0x07c0)
#define USB_DEVICE_ID_VRC2      (0x1125)

static const __u8 vrc2_rdesc_fixed[] = {
        0x05, 0x01,        // Usage Page (Generic Desktop Ctrls)
        0x09, 0x04,        // Usage (Joystick)
        0xA1, 0x01,        // Collection (Application)
        0x09, 0x01,        //   Usage (Pointer)
        0xA1, 0x00,        //   Collection (Physical)
        0x09, 0x30,        //     Usage (X)
        0x09, 0x31,        //     Usage (Y)
        0x15, 0x00,        //     Logical Minimum (0)
        0x26, 0xFF, 0x07,  //     Logical Maximum (2047)
        0x35, 0x00,        //     Physical Minimum (0)
        0x46, 0xFF, 0x00,  //     Physical Maximum (255)
        0x75, 0x10,        //     Report Size (16)
        0x95, 0x02,        //     Report Count (2)
        0x81, 0x02,        //     Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
        0xC0,              //   End Collection
        0x75, 0x08,        //   Report Size (8)
        0x95, 0x03,        //   Report Count (3)
        0x81, 0x03,        //   Input (Cnst,Var,Abs)
        0xC0,              // End Collection
};

static const __u8 *vrc2_report_fixup(struct hid_device *hdev, __u8 *rdesc,
                                     unsigned int *rsize)
{
        hid_info(hdev, "fixing up VRC-2 report descriptor\n");
        *rsize = sizeof(vrc2_rdesc_fixed);
        return vrc2_rdesc_fixed;
}

static int vrc2_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
        int ret;

        /*
         * The device gives us 2 separate USB endpoints.
         * One of those (the one with report descriptor size of 23) is just bogus so ignore it
         */
        if (hdev->dev_rsize == 23)
                return -ENODEV;

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

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

        return 0;
}

static const struct hid_device_id vrc2_devices[] = {
        { HID_USB_DEVICE(USB_VENDOR_ID_VRC2, USB_DEVICE_ID_VRC2) },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(hid, vrc2_devices);

static struct hid_driver vrc2_driver = {
        .name = "vrc2",
        .id_table = vrc2_devices,
        .report_fixup = vrc2_report_fixup,
        .probe = vrc2_probe,
};
module_hid_driver(vrc2_driver);

MODULE_AUTHOR("Marcus Folkesson <marcus.folkesson@gmail.com>");
MODULE_DESCRIPTION("HID driver for VRC-2 2-axis Car controller");
MODULE_LICENSE("GPL");