LXR linux/drivers/hid/hid-gembird.c

   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
  20static 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 */
  41static 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
  60static __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
  97static const struct hid_device_id gembird_devices[] = {
  98        { HID_USB_DEVICE(USB_VENDOR_ID_GEMBIRD,
  99                         USB_DEVICE_ID_GEMBIRD_JPD_DUALFORCE2) },
 100        { }
 101};
 102MODULE_DEVICE_TABLE(hid, gembird_devices);
 103
 104static struct hid_driver gembird_driver = {
 105        .name = "gembird",
 106        .id_table = gembird_devices,
 107        .report_fixup = gembird_report_fixup,
 108};
 109module_hid_driver(gembird_driver);
 110
 111MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
 112MODULE_DESCRIPTION("HID Gembird joypad driver");
 113MODULE_LICENSE("GPL");
 114