xref: /openbmc/linux/drivers/hid/hid-vrc2.c (revision 2c5e8e61)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * HID driver for VRC-2 2-axis Car 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 /*
13  * VID/PID are probably "borrowed", so keep them locally and
14  * do not populate hid-ids.h with those.
15  */
16 #define USB_VENDOR_ID_VRC2	(0x07c0)
17 #define USB_DEVICE_ID_VRC2	(0x1125)
18 
19 static __u8 vrc2_rdesc_fixed[] = {
20 	0x05, 0x01,        // Usage Page (Generic Desktop Ctrls)
21 	0x09, 0x04,        // Usage (Joystick)
22 	0xA1, 0x01,        // Collection (Application)
23 	0x09, 0x01,        //   Usage (Pointer)
24 	0xA1, 0x00,        //   Collection (Physical)
25 	0x09, 0x30,        //     Usage (X)
26 	0x09, 0x31,        //     Usage (Y)
27 	0x15, 0x00,        //     Logical Minimum (0)
28 	0x26, 0xFF, 0x07,  //     Logical Maximum (2047)
29 	0x35, 0x00,        //     Physical Minimum (0)
30 	0x46, 0xFF, 0x00,  //     Physical Maximum (255)
31 	0x75, 0x10,        //     Report Size (16)
32 	0x95, 0x02,        //     Report Count (2)
33 	0x81, 0x02,        //     Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
34 	0xC0,              //   End Collection
35 	0x75, 0x08,        //   Report Size (8)
36 	0x95, 0x03,        //   Report Count (3)
37 	0x81, 0x03,        //   Input (Cnst,Var,Abs)
38 	0xC0,              // End Collection
39 };
40 
vrc2_report_fixup(struct hid_device * hdev,__u8 * rdesc,unsigned int * rsize)41 static __u8 *vrc2_report_fixup(struct hid_device *hdev, __u8 *rdesc,
42 				unsigned int *rsize)
43 {
44 	hid_info(hdev, "fixing up VRC-2 report descriptor\n");
45 	*rsize = sizeof(vrc2_rdesc_fixed);
46 	return vrc2_rdesc_fixed;
47 }
48 
vrc2_probe(struct hid_device * hdev,const struct hid_device_id * id)49 static int vrc2_probe(struct hid_device *hdev, const struct hid_device_id *id)
50 {
51 	int ret;
52 
53 	/*
54 	 * The device gives us 2 separate USB endpoints.
55 	 * One of those (the one with report descriptor size of 23) is just bogus so ignore it
56 	 */
57 	if (hdev->dev_rsize == 23)
58 		return -ENODEV;
59 
60 	ret = hid_parse(hdev);
61 	if (ret) {
62 		hid_err(hdev, "parse failed\n");
63 		return ret;
64 	}
65 
66 	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
67 	if (ret) {
68 		hid_err(hdev, "hw start failed\n");
69 		return ret;
70 	}
71 
72 	return 0;
73 }
74 
75 static const struct hid_device_id vrc2_devices[] = {
76 	{ HID_USB_DEVICE(USB_VENDOR_ID_VRC2, USB_DEVICE_ID_VRC2) },
77 	{ /* sentinel */ }
78 };
79 MODULE_DEVICE_TABLE(hid, vrc2_devices);
80 
81 static struct hid_driver vrc2_driver = {
82 	.name = "vrc2",
83 	.id_table = vrc2_devices,
84 	.report_fixup = vrc2_report_fixup,
85 	.probe = vrc2_probe,
86 };
87 module_hid_driver(vrc2_driver);
88 
89 MODULE_AUTHOR("Marcus Folkesson <marcus.folkesson@gmail.com>");
90 MODULE_DESCRIPTION("HID driver for VRC-2 2-axis Car controller");
91 MODULE_LICENSE("GPL");
92