drivers/hid/hid-elecom.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  HID driver for ELECOM devices:
   4  *  - BM084 Bluetooth Mouse
   5  *  - EX-G Trackballs (M-XT3DRBK, M-XT3URBK, M-XT4DRBK)
   6  *  - DEFT Trackballs (M-DT1DRBK, M-DT1URBK, M-DT2DRBK, M-DT2URBK)
   7  *  - HUGE Trackballs (M-HT1DRBK, M-HT1URBK)
   8  *
   9  *  Copyright (c) 2010 Richard Nauber <Richard.Nauber@gmail.com>
  10  *  Copyright (c) 2016 Yuxuan Shui <yshuiv7@gmail.com>
  11  *  Copyright (c) 2017 Diego Elio Pettenò <flameeyes@flameeyes.eu>
  12  *  Copyright (c) 2017 Alex Manoussakis <amanou@gnu.org>
  13  *  Copyright (c) 2017 Tomasz Kramkowski <tk@the-tk.com>
  14  *  Copyright (c) 2020 YOSHIOKA Takuma <lo48576@hard-wi.red>
  15  *  Copyright (c) 2022 Takahiro Fujii <fujii@xaxxi.net>
  16  */
  17
  18 /*
  19  */
  20
  21 #include <linux/device.h>
  22 #include <linux/hid.h>
  23 #include <linux/module.h>
  24
  25 #include "hid-ids.h"
  26
  27 /*
  28  * Certain ELECOM mice misreport their button count meaning that they only work
  29  * correctly with the ELECOM mouse assistant software which is unavailable for
  30  * Linux. A four extra INPUT reports and a FEATURE report are described by the
  31  * report descriptor but it does not appear that these enable software to
  32  * control what the extra buttons map to. The only simple and straightforward
  33  * solution seems to involve fixing up the report descriptor.
  34  */
  35 #define MOUSE_BUTTONS_MAX 8
  36 static void mouse_button_fixup(struct hid_device *hdev,
  37                                __u8 *rdesc, unsigned int rsize,
  38                                unsigned int button_bit_count,
  39                                unsigned int padding_bit,
  40                                unsigned int button_report_size,
  41                                unsigned int button_usage_maximum,
  42                                int nbuttons)
  43 {
  44         if (rsize < 32 || rdesc[button_bit_count] != 0x95 ||
  45             rdesc[button_report_size] != 0x75 ||
  46             rdesc[button_report_size + 1] != 0x01 ||
  47             rdesc[button_usage_maximum] != 0x29 || rdesc[padding_bit] != 0x75)
  48                 return;
  49         hid_info(hdev, "Fixing up Elecom mouse button count\n");
  50         nbuttons = clamp(nbuttons, 0, MOUSE_BUTTONS_MAX);
  51         rdesc[button_bit_count + 1] = nbuttons;
  52         rdesc[button_usage_maximum + 1] = nbuttons;
  53         rdesc[padding_bit + 1] = MOUSE_BUTTONS_MAX - nbuttons;
  54 }
  55
  56 static __u8 *elecom_report_fixup(struct hid_device *hdev, __u8 *rdesc,
  57                 unsigned int *rsize)
  58 {
  59         switch (hdev->product) {
  60         case USB_DEVICE_ID_ELECOM_BM084:
  61                 /* The BM084 Bluetooth mouse includes a non-existing horizontal
  62                  * wheel in the HID descriptor. */
  63                 if (*rsize >= 48 && rdesc[46] == 0x05 && rdesc[47] == 0x0c) {
  64                         hid_info(hdev, "Fixing up Elecom BM084 report descriptor\n");
  65                         rdesc[47] = 0x00;
  66                 }
  67                 break;
  68         case USB_DEVICE_ID_ELECOM_M_XGL20DLBK:
  69                 /*
  70                  * Report descriptor format:
  71                  * 20: button bit count
  72                  * 28: padding bit count
  73                  * 22: button report size
  74                  * 14: button usage maximum
  75                  */
  76                 mouse_button_fixup(hdev, rdesc, *rsize, 20, 28, 22, 14, 8);
  77                 break;
  78         case USB_DEVICE_ID_ELECOM_M_XT3URBK:
  79         case USB_DEVICE_ID_ELECOM_M_XT3DRBK:
  80         case USB_DEVICE_ID_ELECOM_M_XT4DRBK:
  81                 /*
  82                  * Report descriptor format:
  83                  * 12: button bit count
  84                  * 30: padding bit count
  85                  * 14: button report size
  86                  * 20: button usage maximum
  87                  */
  88                 mouse_button_fixup(hdev, rdesc, *rsize, 12, 30, 14, 20, 6);
  89                 break;
  90         case USB_DEVICE_ID_ELECOM_M_DT1URBK:
  91         case USB_DEVICE_ID_ELECOM_M_DT1DRBK:
  92         case USB_DEVICE_ID_ELECOM_M_HT1URBK:
  93         case USB_DEVICE_ID_ELECOM_M_HT1DRBK_010D:
  94                 /*
  95                  * Report descriptor format:
  96                  * 12: button bit count
  97                  * 30: padding bit count
  98                  * 14: button report size
  99                  * 20: button usage maximum
 100                  */
 101                 mouse_button_fixup(hdev, rdesc, *rsize, 12, 30, 14, 20, 8);
 102                 break;
 103         case USB_DEVICE_ID_ELECOM_M_HT1DRBK_011C:
 104                 /*
 105                  * Report descriptor format:
 106                  * 22: button bit count
 107                  * 30: padding bit count
 108                  * 24: button report size
 109                  * 16: button usage maximum
 110                  */
 111                 mouse_button_fixup(hdev, rdesc, *rsize, 22, 30, 24, 16, 8);
 112                 break;
 113         }
 114         return rdesc;
 115 }
 116
 117 static const struct hid_device_id elecom_devices[] = {
 118         { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_BM084) },
 119         { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XGL20DLBK) },
 120         { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3URBK) },
 121         { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3DRBK) },
 122         { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT4DRBK) },
 123         { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT1URBK) },
 124         { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT1DRBK) },
 125         { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1URBK) },
 126         { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1DRBK_010D) },
 127         { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1DRBK_011C) },
 128         { }
 129 };
 130 MODULE_DEVICE_TABLE(hid, elecom_devices);
 131
 132 static struct hid_driver elecom_driver = {
 133         .name = "elecom",
 134         .id_table = elecom_devices,
 135         .report_fixup = elecom_report_fixup
 136 };
 137 module_hid_driver(elecom_driver);
 138
 139 MODULE_LICENSE("GPL");