1/*
2 * HID driver for Gembird Joypad, "PC Game Controller"
3 *
4 * Copyright (c) 2015 Red Hat, Inc
5 * Copyright (c) 2015 Benjamin Tissoires
6 */
7
8/*
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the Free
11 * Software Foundation; either version 2 of the License, or (at your option)
12 * any later version.
13 */
14
15#include <linux/device.h>
16#include <linux/hid.h>
17#include <linux/module.h>
18
19#include "hid-ids.h"
20
21#define GEMBIRD_START_FAULTY_RDESC 8
22
23static const __u8 gembird_jpd_faulty_rdesc[] = {
24 0x75, 0x08, /* Report Size (8) */
25 0x95, 0x05, /* Report Count (5) */
26 0x15, 0x00, /* Logical Minimum (0) */
27 0x26, 0xff, 0x00, /* Logical Maximum (255) */
28 0x35, 0x00, /* Physical Minimum (0) */
29 0x46, 0xff, 0x00, /* Physical Maximum (255) */
30 0x09, 0x30, /* Usage (X) */
31 0x09, 0x31, /* Usage (Y) */
32 0x09, 0x32, /* Usage (Z) */
33 0x09, 0x32, /* Usage (Z) */
34 0x09, 0x35, /* Usage (Rz) */
35 0x81, 0x02, /* Input (Data,Var,Abs) */
36};
37
38/*
39 * we fix the report descriptor by:
40 * - marking the first Z axis as constant (so it is ignored by HID)
41 * - assign the original second Z to Rx
42 * - assign the original Rz to Ry
43 */
44static const __u8 gembird_jpd_fixed_rdesc[] = {
45 0x75, 0x08, /* Report Size (8) */
46 0x95, 0x02, /* Report Count (2) */
47 0x15, 0x00, /* Logical Minimum (0) */
48 0x26, 0xff, 0x00, /* Logical Maximum (255) */
49 0x35, 0x00, /* Physical Minimum (0) */
50 0x46, 0xff, 0x00, /* Physical Maximum (255) */
51 0x09, 0x30, /* Usage (X) */
52 0x09, 0x31, /* Usage (Y) */
53 0x81, 0x02, /* Input (Data,Var,Abs) */
54 0x95, 0x01, /* Report Count (1) */
55 0x09, 0x32, /* Usage (Z) */
56 0x81, 0x01, /* Input (Cnst,Arr,Abs) */
57 0x95, 0x02, /* Report Count (2) */
58 0x09, 0x33, /* Usage (Rx) */
59 0x09, 0x34, /* Usage (Ry) */
60 0x81, 0x02, /* Input (Data,Var,Abs) */
61};
62
63static __u8 *gembird_report_fixup(struct hid_device *hdev, __u8 *rdesc,
64 unsigned int *rsize)
65{
66 __u8 *new_rdesc;
67 /* delta_size is > 0 */
68 size_t delta_size = sizeof(gembird_jpd_fixed_rdesc) -
69 sizeof(gembird_jpd_faulty_rdesc);
70 size_t new_size = *rsize + delta_size;
71
72 if (*rsize >= 31 && !memcmp(&rdesc[GEMBIRD_START_FAULTY_RDESC],
73 gembird_jpd_faulty_rdesc,
74 sizeof(gembird_jpd_faulty_rdesc))) {
75 new_rdesc = devm_kzalloc(&hdev->dev, new_size, GFP_KERNEL);
76 if (new_rdesc == NULL)
77 return rdesc;
78
79 dev_info(&hdev->dev,
80 "fixing Gembird JPD-DualForce 2 report descriptor.\n");
81
82 /* start by copying the end of the rdesc */
83 memcpy(new_rdesc + delta_size, rdesc, *rsize);
84
85 /* add the correct beginning */
86 memcpy(new_rdesc, rdesc, GEMBIRD_START_FAULTY_RDESC);
87
88 /* replace the faulty part with the fixed one */
89 memcpy(new_rdesc + GEMBIRD_START_FAULTY_RDESC,
90 gembird_jpd_fixed_rdesc,
91 sizeof(gembird_jpd_fixed_rdesc));
92
93 *rsize = new_size;
94 rdesc = new_rdesc;
95 }
96
97 return rdesc;
98}
99
100static const struct hid_device_id gembird_devices[] = {
101 { HID_USB_DEVICE(USB_VENDOR_ID_GEMBIRD,
102 USB_DEVICE_ID_GEMBIRD_JPD_DUALFORCE2) },
103 { }
104};
105MODULE_DEVICE_TABLE(hid, gembird_devices);
106
107static struct hid_driver gembird_driver = {
108 .name = "gembird",
109 .id_table = gembird_devices,
110 .report_fixup = gembird_report_fixup,
111};
112module_hid_driver(gembird_driver);
113
114MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
115MODULE_DESCRIPTION("HID Gembird joypad driver");
116MODULE_LICENSE("GPL");
117