1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * HID driver for PhoenixRC 8-axis flight controller
  4 *
  5 * Copyright (C) 2022 Marcus Folkesson <marcus.folkesson@gmail.com>
  6 */
  7
  8#include <linux/device.h>
  9#include <linux/hid.h>
 10#include <linux/module.h>
 11
 12#include "hid-ids.h"
 13
 14struct pxrc_priv {
 15	u8 slider;
 16	u8 dial;
 17	bool alternate;
 18};
 19
 20static const __u8 pxrc_rdesc_fixed[] = {
 21	0x05, 0x01,        // Usage Page (Generic Desktop Ctrls)
 22	0x09, 0x04,        // Usage (Joystick)
 23	0xA1, 0x01,        // Collection (Application)
 24	0x09, 0x01,        //   Usage (Pointer)
 25	0xA1, 0x00,        //   Collection (Physical)
 26	0x09, 0x30,        //     Usage (X)
 27	0x09, 0x36,        //     Usage (Slider)
 28	0x09, 0x31,        //     Usage (Y)
 29	0x09, 0x32,        //     Usage (Z)
 30	0x09, 0x33,        //     Usage (Rx)
 31	0x09, 0x34,        //     Usage (Ry)
 32	0x09, 0x35,        //     Usage (Rz)
 33	0x09, 0x37,        //     Usage (Dial)
 34	0x15, 0x00,        //     Logical Minimum (0)
 35	0x26, 0xFF, 0x00,  //     Logical Maximum (255)
 36	0x35, 0x00,        //     Physical Minimum (0)
 37	0x46, 0xFF, 0x00,  //     Physical Maximum (255)
 38	0x75, 0x08,        //     Report Size (8)
 39	0x95, 0x08,        //     Report Count (8)
 40	0x81, 0x02,        //     Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
 41	0xC0,              //   End Collection
 42	0xC0,              // End Collection
 43};
 44
 45static const __u8 *pxrc_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 46				     unsigned int *rsize)
 47{
 48	hid_info(hdev, "fixing up PXRC report descriptor\n");
 49	*rsize = sizeof(pxrc_rdesc_fixed);
 50	return pxrc_rdesc_fixed;
 51}
 52
 53static int pxrc_raw_event(struct hid_device *hdev, struct hid_report *report,
 54	 u8 *data, int size)
 55{
 56	struct pxrc_priv *priv = hid_get_drvdata(hdev);
 57
 58	if (priv->alternate)
 59		priv->slider = data[7];
 60	else
 61		priv->dial = data[7];
 62
 63	data[1] = priv->slider;
 64	data[7] = priv->dial;
 65
 66	priv->alternate = !priv->alternate;
 67	return 0;
 68}
 69
 70static int pxrc_probe(struct hid_device *hdev, const struct hid_device_id *id)
 71{
 72	int ret;
 73	struct pxrc_priv *priv;
 74
 75	priv = devm_kzalloc(&hdev->dev, sizeof(*priv), GFP_KERNEL);
 76	if (!priv)
 77		return -ENOMEM;
 78	hid_set_drvdata(hdev, priv);
 79
 80	ret = hid_parse(hdev);
 81	if (ret) {
 82		hid_err(hdev, "parse failed\n");
 83		return ret;
 84	}
 85
 86	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 87	if (ret) {
 88		hid_err(hdev, "hw start failed\n");
 89		return ret;
 90	}
 91
 92	return 0;
 93}
 94
 95static const struct hid_device_id pxrc_devices[] = {
 96	{ HID_USB_DEVICE(USB_VENDOR_ID_MULTIPLE_1781, USB_DEVICE_ID_PHOENIXRC) },
 97	{ /* sentinel */ }
 98};
 99MODULE_DEVICE_TABLE(hid, pxrc_devices);
100
101static struct hid_driver pxrc_driver = {
102	.name = "hid-pxrc",
103	.id_table = pxrc_devices,
104	.report_fixup = pxrc_report_fixup,
105	.probe = pxrc_probe,
106	.raw_event = pxrc_raw_event,
107};
108module_hid_driver(pxrc_driver);
109
110MODULE_AUTHOR("Marcus Folkesson <marcus.folkesson@gmail.com>");
111MODULE_DESCRIPTION("HID driver for PXRC 8-axis flight controller");
112MODULE_LICENSE("GPL");