1 /* 2 * HID driver for Redragon keyboards 3 * 4 * Copyright (c) 2017 Robert Munteanu 5 * SPDX-License-Identifier: GPL-2.0+ 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 22 /* 23 * The Redragon Asura keyboard sends an incorrect HID descriptor. 24 * At byte 100 it contains 25 * 26 * 0x81, 0x00 27 * 28 * which is Input (Data, Arr, Abs), but it should be 29 * 30 * 0x81, 0x02 31 * 32 * which is Input (Data, Var, Abs), which is consistent with the way 33 * key codes are generated. 34 */ 35 36 static __u8 *redragon_report_fixup(struct hid_device *hdev, __u8 *rdesc, 37 unsigned int *rsize) 38 { 39 if (*rsize >= 102 && rdesc[100] == 0x81 && rdesc[101] == 0x00) { 40 dev_info(&hdev->dev, "Fixing Redragon ASURA report descriptor.\n"); 41 rdesc[101] = 0x02; 42 } 43 44 return rdesc; 45 } 46 47 static int redragon_probe(struct hid_device *dev, 48 const struct hid_device_id *id) 49 { 50 int ret; 51 52 ret = hid_parse(dev); 53 if (ret) { 54 hid_err(dev, "parse failed\n"); 55 return ret; 56 } 57 58 /* do not register unused input device */ 59 if (dev->maxapplication == 1) 60 return 0; 61 62 ret = hid_hw_start(dev, HID_CONNECT_DEFAULT); 63 if (ret) { 64 hid_err(dev, "hw start failed\n"); 65 return ret; 66 } 67 68 return 0; 69 } 70 static const struct hid_device_id redragon_devices[] = { 71 {HID_USB_DEVICE(USB_VENDOR_ID_JESS, USB_DEVICE_ID_REDRAGON_ASURA)}, 72 {} 73 }; 74 75 MODULE_DEVICE_TABLE(hid, redragon_devices); 76 77 static struct hid_driver redragon_driver = { 78 .name = "redragon", 79 .id_table = redragon_devices, 80 .report_fixup = redragon_report_fixup, 81 .probe = redragon_probe 82 }; 83 84 module_hid_driver(redragon_driver); 85 86 MODULE_LICENSE("GPL"); 87