1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * HID driver for Gembird Joypad, "PC Game Controller"
4 *
5 * Copyright (c) 2015 Red Hat, Inc
6 * Copyright (c) 2015 Benjamin Tissoires
7 */
8
9 /*
10 */
11
12 #include <linux/device.h>
13 #include <linux/hid.h>
14 #include <linux/module.h>
15
16 #include "hid-ids.h"
17
18 #define GEMBIRD_START_FAULTY_RDESC 8
19
20 static const __u8 gembird_jpd_faulty_rdesc[] = {
21 0x75, 0x08, /* Report Size (8) */
22 0x95, 0x05, /* Report Count (5) */
23 0x15, 0x00, /* Logical Minimum (0) */
24 0x26, 0xff, 0x00, /* Logical Maximum (255) */
25 0x35, 0x00, /* Physical Minimum (0) */
26 0x46, 0xff, 0x00, /* Physical Maximum (255) */
27 0x09, 0x30, /* Usage (X) */
28 0x09, 0x31, /* Usage (Y) */
29 0x09, 0x32, /* Usage (Z) */
30 0x09, 0x32, /* Usage (Z) */
31 0x09, 0x35, /* Usage (Rz) */
32 0x81, 0x02, /* Input (Data,Var,Abs) */
33 };
34
35 /*
36 * we fix the report descriptor by:
37 * - marking the first Z axis as constant (so it is ignored by HID)
38 * - assign the original second Z to Rx
39 * - assign the original Rz to Ry
40 */
41 static const __u8 gembird_jpd_fixed_rdesc[] = {
42 0x75, 0x08, /* Report Size (8) */
43 0x95, 0x02, /* Report Count (2) */
44 0x15, 0x00, /* Logical Minimum (0) */
45 0x26, 0xff, 0x00, /* Logical Maximum (255) */
46 0x35, 0x00, /* Physical Minimum (0) */
47 0x46, 0xff, 0x00, /* Physical Maximum (255) */
48 0x09, 0x30, /* Usage (X) */
49 0x09, 0x31, /* Usage (Y) */
50 0x81, 0x02, /* Input (Data,Var,Abs) */
51 0x95, 0x01, /* Report Count (1) */
52 0x09, 0x32, /* Usage (Z) */
53 0x81, 0x01, /* Input (Cnst,Arr,Abs) */
54 0x95, 0x02, /* Report Count (2) */
55 0x09, 0x33, /* Usage (Rx) */
56 0x09, 0x34, /* Usage (Ry) */
57 0x81, 0x02, /* Input (Data,Var,Abs) */
58 };
59
60 static __u8 *gembird_report_fixup(struct hid_device *hdev, __u8 *rdesc,
61 unsigned int *rsize)
62 {
63 __u8 *new_rdesc;
64 /* delta_size is > 0 */
65 size_t delta_size = sizeof(gembird_jpd_fixed_rdesc) -
66 sizeof(gembird_jpd_faulty_rdesc);
67 size_t new_size = *rsize + delta_size;
68
69 if (*rsize >= 31 && !memcmp(&rdesc[GEMBIRD_START_FAULTY_RDESC],
70 gembird_jpd_faulty_rdesc,
71 sizeof(gembird_jpd_faulty_rdesc))) {
72 new_rdesc = devm_kzalloc(&hdev->dev, new_size, GFP_KERNEL);
73 if (new_rdesc == NULL)
74 return rdesc;
75
76 dev_info(&hdev->dev,
77 "fixing Gembird JPD-DualForce 2 report descriptor.\n");
78
79 /* start by copying the end of the rdesc */
80 memcpy(new_rdesc + delta_size, rdesc, *rsize);
81
82 /* add the correct beginning */
83 memcpy(new_rdesc, rdesc, GEMBIRD_START_FAULTY_RDESC);
84
85 /* replace the faulty part with the fixed one */
86 memcpy(new_rdesc + GEMBIRD_START_FAULTY_RDESC,
87 gembird_jpd_fixed_rdesc,
88 sizeof(gembird_jpd_fixed_rdesc));
89
90 *rsize = new_size;
91 rdesc = new_rdesc;
92 }
93
94 return rdesc;
95 }
96
97 static const struct hid_device_id gembird_devices[] = {
98 { HID_USB_DEVICE(USB_VENDOR_ID_GEMBIRD,
99 USB_DEVICE_ID_GEMBIRD_JPD_DUALFORCE2) },
100 { }
101 };
102 MODULE_DEVICE_TABLE(hid, gembird_devices);
103
104 static struct hid_driver gembird_driver = {
105 .name = "gembird",
106 .id_table = gembird_devices,
107 .report_fixup = gembird_report_fixup,
108 };
109 module_hid_driver(gembird_driver);
110
111 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
112 MODULE_DESCRIPTION("HID Gembird joypad driver");
113 MODULE_LICENSE("GPL");