// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  HID driver for Ravcore Javelin & VKB Joysticks
 *  Currently supported devices are:
 *
 *    Ravcore Javelin: v11C0 p5607
 *    VKB Gladiator MKII: v231d p0121
 *
 *  Copyright (c) 2019 John Grs <johnpgrs@gmail.com>
*/

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

#define USB_VENDOR_ID_RAVCORE		0x11C0
#define USB_DEVICE_ID_RAVCORE_VKB5607	0x5607
#define USB_VENDOR_ID_VKB     0x231d
#define USB_DEVICE_ID_GLADIATOR 0x0121

static const struct {
	__s32 x;
	__s32 y;
}  hid_hat_to_axis[] = {{ 0, 0}, { 0,-1}, { 1,-1}, { 1, 0}, { 1, 1}, { 0, 1}, {-1, 1}, {-1, 0}, {-1,-1}};

static __u8 *gladiator_report_fixup(struct hid_device *hdev, __u8 *rdesc,	unsigned int *rsize)
{
	hid_info(hdev, "Fix HAT for Gladiator MKII Joystick\n");
	rdesc[177]=0x08;		// Logigal Maximum = 8
	return rdesc;
}

static int gladiator_event(struct hid_device *hdev, struct hid_field *field, struct hid_usage *usage, __s32 value)
{
   struct input_dev *input = field->hidinput->input;

   if (usage->type == EV_ABS && usage->code == 16) {
      if (value > 239) { value=-1; } else { value /= 30; }
      value +=1;
      input_event(input, usage->type, usage->code, hid_hat_to_axis[value].x);
      input_event(input, usage->type, usage->code+1, hid_hat_to_axis[value].y);
      return 1;
   }
   return 0;
}

static const struct hid_device_id gladiator_devices[] = {
    { HID_USB_DEVICE(USB_VENDOR_ID_RAVCORE, USB_DEVICE_ID_RAVCORE_VKB5607) },
	{ HID_USB_DEVICE(USB_VENDOR_ID_VKB, USB_DEVICE_ID_GLADIATOR) },
	{ }
};

MODULE_DEVICE_TABLE(hid, gladiator_devices);

static struct hid_driver gladiator_driver = {
	.name = "VKB Gladiator MKII",
	.id_table = gladiator_devices,
    .report_fixup = gladiator_report_fixup,
    .event = gladiator_event,
};

module_hid_driver(gladiator_driver);

MODULE_AUTHOR("John Grs <johnpgrs@gmail.com>");
MODULE_DESCRIPTION("VKB Gladiator MKII driver");
MODULE_LICENSE("GPL");