drivers/hid/hid-vrc2.c

   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
  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
  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");