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  */
  16
  17 /*
  18  */
  19
  20 #include <linux/device.h>
  21 #include <linux/hid.h>
  22 #include <linux/module.h>
  23
  24 #include "hid-ids.h"
  25
  26 /*
  27  * Certain ELECOM mice misreport their button count meaning that they only work
  28  * correctly with the ELECOM mouse assistant software which is unavailable for
  29  * Linux. A four extra INPUT reports and a FEATURE report are described by the
  30  * report descriptor but it does not appear that these enable software to
  31  * control what the extra buttons map to. The only simple and straightforward
  32  * solution seems to involve fixing up the report descriptor.
  33  */
  34 #define MOUSE_BUTTONS_MAX 8
  35 static void mouse_button_fixup(struct hid_device *hdev,
  36                                __u8 *rdesc, unsigned int rsize,
  37                                unsigned int button_bit_count,
  38                                unsigned int padding_bit,
  39                                unsigned int button_report_size,
  40                                unsigned int button_usage_maximum,
  41                                int nbuttons)
  42 {
  43         if (rsize < 32 || rdesc[button_bit_count] != 0x95 ||
  44             rdesc[button_report_size] != 0x75 ||
  45             rdesc[button_report_size + 1] != 0x01 ||
  46             rdesc[button_usage_maximum] != 0x29 || rdesc[padding_bit] != 0x75)
  47                 return;
  48         hid_info(hdev, "Fixing up Elecom mouse button count\n");
  49         nbuttons = clamp(nbuttons, 0, MOUSE_BUTTONS_MAX);
  50         rdesc[button_bit_count + 1] = nbuttons;
  51         rdesc[button_usage_maximum + 1] = nbuttons;
  52         rdesc[padding_bit + 1] = MOUSE_BUTTONS_MAX - nbuttons;
  53 }
  54
  55 static __u8 *elecom_report_fixup(struct hid_device *hdev, __u8 *rdesc,
  56                 unsigned int *rsize)
  57 {
  58         switch (hdev->product) {
  59         case USB_DEVICE_ID_ELECOM_BM084:
  60                 /* The BM084 Bluetooth mouse includes a non-existing horizontal
  61                  * wheel in the HID descriptor. */
  62                 if (*rsize >= 48 && rdesc[46] == 0x05 && rdesc[47] == 0x0c) {
  63                         hid_info(hdev, "Fixing up Elecom BM084 report descriptor\n");
  64                         rdesc[47] = 0x00;
  65                 }
  66                 break;
  67         case USB_DEVICE_ID_ELECOM_M_XGL20DLBK:
  68                 /*
  69                  * Report descriptor format:
  70                  * 20: button bit count
  71                  * 28: padding bit count
  72                  * 22: button report size
  73                  * 14: button usage maximum
  74                  */
  75                 mouse_button_fixup(hdev, rdesc, *rsize, 20, 28, 22, 14, 8);
  76                 break;
  77         case USB_DEVICE_ID_ELECOM_M_XT3URBK:
  78         case USB_DEVICE_ID_ELECOM_M_XT3DRBK:
  79         case USB_DEVICE_ID_ELECOM_M_XT4DRBK:
  80                 /*
  81                  * Report descriptor format:
  82                  * 12: button bit count
  83                  * 30: padding bit count
  84                  * 14: button report size
  85                  * 20: button usage maximum
  86                  */
  87                 mouse_button_fixup(hdev, rdesc, *rsize, 12, 30, 14, 20, 6);
  88                 break;
  89         case USB_DEVICE_ID_ELECOM_M_DT1URBK:
  90         case USB_DEVICE_ID_ELECOM_M_DT1DRBK:
  91         case USB_DEVICE_ID_ELECOM_M_HT1URBK:
  92         case USB_DEVICE_ID_ELECOM_M_HT1DRBK:
  93                 /*
  94                  * Report descriptor format:
  95                  * 12: button bit count
  96                  * 30: padding bit count
  97                  * 14: button report size
  98                  * 20: button usage maximum
  99                  */
 100                 mouse_button_fixup(hdev, rdesc, *rsize, 12, 30, 14, 20, 8);
 101                 break;
 102         }
 103         return rdesc;
 104 }
 105
 106 static const struct hid_device_id elecom_devices[] = {
 107         { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_BM084) },
 108         { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XGL20DLBK) },
 109         { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3URBK) },
 110         { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3DRBK) },
 111         { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT4DRBK) },
 112         { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT1URBK) },
 113         { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT1DRBK) },
 114         { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1URBK) },
 115         { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1DRBK) },
 116         { }
 117 };
 118 MODULE_DEVICE_TABLE(hid, elecom_devices);
 119
 120 static struct hid_driver elecom_driver = {
 121         .name = "elecom",
 122         .id_table = elecom_devices,
 123         .report_fixup = elecom_report_fixup
 124 };
 125 module_hid_driver(elecom_driver);
 126
 127 MODULE_LICENSE("GPL");