GNU Linux-libre 4.4.289-gnu1
[releases.git] / drivers / hid / hid-gembird.c
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
23 static 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  */
44 static 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
63 static __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
100 static const struct hid_device_id gembird_devices[] = {
101         { HID_USB_DEVICE(USB_VENDOR_ID_GEMBIRD,
102                          USB_DEVICE_ID_GEMBIRD_JPD_DUALFORCE2) },
103         { }
104 };
105 MODULE_DEVICE_TABLE(hid, gembird_devices);
106
107 static struct hid_driver gembird_driver = {
108         .name = "gembird",
109         .id_table = gembird_devices,
110         .report_fixup = gembird_report_fixup,
111 };
112 module_hid_driver(gembird_driver);
113
114 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
115 MODULE_DESCRIPTION("HID Gembird joypad driver");
116 MODULE_LICENSE("GPL");