drivers/hid/hid-elecom.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  *  HID driver for ELECOM devices:
0004  *  - BM084 Bluetooth Mouse
0005  *  - EX-G Trackballs (M-XT3DRBK, M-XT3URBK, M-XT4DRBK)
0006  *  - DEFT Trackballs (M-DT1DRBK, M-DT1URBK, M-DT2DRBK, M-DT2URBK)
0007  *  - HUGE Trackballs (M-HT1DRBK, M-HT1URBK)
0008  *
0009  *  Copyright (c) 2010 Richard Nauber <Richard.Nauber@gmail.com>
0010  *  Copyright (c) 2016 Yuxuan Shui <yshuiv7@gmail.com>
0011  *  Copyright (c) 2017 Diego Elio Pettenò <flameeyes@flameeyes.eu>
0012  *  Copyright (c) 2017 Alex Manoussakis <amanou@gnu.org>
0013  *  Copyright (c) 2017 Tomasz Kramkowski <tk@the-tk.com>
0014  *  Copyright (c) 2020 YOSHIOKA Takuma <lo48576@hard-wi.red>
0015  */
0016
0017 /*
0018  */
0019
0020 #include <linux/device.h>
0021 #include <linux/hid.h>
0022 #include <linux/module.h>
0023
0024 #include "hid-ids.h"
0025
0026 /*
0027  * Certain ELECOM mice misreport their button count meaning that they only work
0028  * correctly with the ELECOM mouse assistant software which is unavailable for
0029  * Linux. A four extra INPUT reports and a FEATURE report are described by the
0030  * report descriptor but it does not appear that these enable software to
0031  * control what the extra buttons map to. The only simple and straightforward
0032  * solution seems to involve fixing up the report descriptor.
0033  */
0034 #define MOUSE_BUTTONS_MAX 8
0035 static void mouse_button_fixup(struct hid_device *hdev,
0036                    __u8 *rdesc, unsigned int rsize,
0037                    unsigned int button_bit_count,
0038                    unsigned int padding_bit,
0039                    unsigned int button_report_size,
0040                    unsigned int button_usage_maximum,
0041                    int nbuttons)
0042 {
0043     if (rsize < 32 || rdesc[button_bit_count] != 0x95 ||
0044         rdesc[button_report_size] != 0x75 ||
0045         rdesc[button_report_size + 1] != 0x01 ||
0046         rdesc[button_usage_maximum] != 0x29 || rdesc[padding_bit] != 0x75)
0047         return;
0048     hid_info(hdev, "Fixing up Elecom mouse button count\n");
0049     nbuttons = clamp(nbuttons, 0, MOUSE_BUTTONS_MAX);
0050     rdesc[button_bit_count + 1] = nbuttons;
0051     rdesc[button_usage_maximum + 1] = nbuttons;
0052     rdesc[padding_bit + 1] = MOUSE_BUTTONS_MAX - nbuttons;
0053 }
0054
0055 static __u8 *elecom_report_fixup(struct hid_device *hdev, __u8 *rdesc,
0056         unsigned int *rsize)
0057 {
0058     switch (hdev->product) {
0059     case USB_DEVICE_ID_ELECOM_BM084:
0060         /* The BM084 Bluetooth mouse includes a non-existing horizontal
0061          * wheel in the HID descriptor. */
0062         if (*rsize >= 48 && rdesc[46] == 0x05 && rdesc[47] == 0x0c) {
0063             hid_info(hdev, "Fixing up Elecom BM084 report descriptor\n");
0064             rdesc[47] = 0x00;
0065         }
0066         break;
0067     case USB_DEVICE_ID_ELECOM_M_XGL20DLBK:
0068         /*
0069          * Report descriptor format:
0070          * 20: button bit count
0071          * 28: padding bit count
0072          * 22: button report size
0073          * 14: button usage maximum
0074          */
0075         mouse_button_fixup(hdev, rdesc, *rsize, 20, 28, 22, 14, 8);
0076         break;
0077     case USB_DEVICE_ID_ELECOM_M_XT3URBK:
0078     case USB_DEVICE_ID_ELECOM_M_XT3DRBK:
0079     case USB_DEVICE_ID_ELECOM_M_XT4DRBK:
0080         /*
0081          * Report descriptor format:
0082          * 12: button bit count
0083          * 30: padding bit count
0084          * 14: button report size
0085          * 20: button usage maximum
0086          */
0087         mouse_button_fixup(hdev, rdesc, *rsize, 12, 30, 14, 20, 6);
0088         break;
0089     case USB_DEVICE_ID_ELECOM_M_DT1URBK:
0090     case USB_DEVICE_ID_ELECOM_M_DT1DRBK:
0091     case USB_DEVICE_ID_ELECOM_M_HT1URBK:
0092     case USB_DEVICE_ID_ELECOM_M_HT1DRBK:
0093         /*
0094          * Report descriptor format:
0095          * 12: button bit count
0096          * 30: padding bit count
0097          * 14: button report size
0098          * 20: button usage maximum
0099          */
0100         mouse_button_fixup(hdev, rdesc, *rsize, 12, 30, 14, 20, 8);
0101         break;
0102     }
0103     return rdesc;
0104 }
0105
0106 static const struct hid_device_id elecom_devices[] = {
0107     { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_BM084) },
0108     { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XGL20DLBK) },
0109     { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3URBK) },
0110     { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3DRBK) },
0111     { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT4DRBK) },
0112     { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT1URBK) },
0113     { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT1DRBK) },
0114     { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1URBK) },
0115     { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1DRBK) },
0116     { }
0117 };
0118 MODULE_DEVICE_TABLE(hid, elecom_devices);
0119
0120 static struct hid_driver elecom_driver = {
0121     .name = "elecom",
0122     .id_table = elecom_devices,
0123     .report_fixup = elecom_report_fixup
0124 };
0125 module_hid_driver(elecom_driver);
0126
0127 MODULE_LICENSE("GPL");