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 *  - HUGE Plus Trackball (M-HT1MRBK)
  9 *
 10 *  Copyright (c) 2010 Richard Nauber <Richard.Nauber@gmail.com>
 11 *  Copyright (c) 2016 Yuxuan Shui <yshuiv7@gmail.com>
 12 *  Copyright (c) 2017 Diego Elio Pettenò <flameeyes@flameeyes.eu>
 13 *  Copyright (c) 2017 Alex Manoussakis <amanou@gnu.org>
 14 *  Copyright (c) 2017 Tomasz Kramkowski <tk@the-tk.com>
 15 *  Copyright (c) 2020 YOSHIOKA Takuma <lo48576@hard-wi.red>
 16 *  Copyright (c) 2022 Takahiro Fujii <fujii@xaxxi.net>
 17 */
 18
 19/*
 20 */
 21
 22#include <linux/device.h>
 23#include <linux/hid.h>
 24#include <linux/module.h>
 25
 26#include "hid-ids.h"
 27
 28/*
 29 * Certain ELECOM mice misreport their button count meaning that they only work
 30 * correctly with the ELECOM mouse assistant software which is unavailable for
 31 * Linux. A four extra INPUT reports and a FEATURE report are described by the
 32 * report descriptor but it does not appear that these enable software to
 33 * control what the extra buttons map to. The only simple and straightforward
 34 * solution seems to involve fixing up the report descriptor.
 35 */
 36#define MOUSE_BUTTONS_MAX 8
 37static void mouse_button_fixup(struct hid_device *hdev,
 38			       __u8 *rdesc, unsigned int rsize,
 39			       unsigned int button_bit_count,
 40			       unsigned int padding_bit,
 41			       unsigned int button_report_size,
 42			       unsigned int button_usage_maximum,
 43			       int nbuttons)
 44{
 45	if (rsize < 32 || rdesc[button_bit_count] != 0x95 ||
 46	    rdesc[button_report_size] != 0x75 ||
 47	    rdesc[button_report_size + 1] != 0x01 ||
 48	    rdesc[button_usage_maximum] != 0x29 || rdesc[padding_bit] != 0x75)
 49		return;
 50	hid_info(hdev, "Fixing up Elecom mouse button count\n");
 51	nbuttons = clamp(nbuttons, 0, MOUSE_BUTTONS_MAX);
 52	rdesc[button_bit_count + 1] = nbuttons;
 53	rdesc[button_usage_maximum + 1] = nbuttons;
 54	rdesc[padding_bit + 1] = MOUSE_BUTTONS_MAX - nbuttons;
 55}
 56
 57static const __u8 *elecom_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 58		unsigned int *rsize)
 59{
 60	switch (hdev->product) {
 61	case USB_DEVICE_ID_ELECOM_BM084:
 62		/* The BM084 Bluetooth mouse includes a non-existing horizontal
 63		 * wheel in the HID descriptor. */
 64		if (*rsize >= 48 && rdesc[46] == 0x05 && rdesc[47] == 0x0c) {
 65			hid_info(hdev, "Fixing up Elecom BM084 report descriptor\n");
 66			rdesc[47] = 0x00;
 67		}
 68		break;
 69	case USB_DEVICE_ID_ELECOM_M_XGL20DLBK:
 70		/*
 71		 * Report descriptor format:
 72		 * 20: button bit count
 73		 * 28: padding bit count
 74		 * 22: button report size
 75		 * 14: button usage maximum
 76		 */
 77		mouse_button_fixup(hdev, rdesc, *rsize, 20, 28, 22, 14, 8);
 78		break;
 79	case USB_DEVICE_ID_ELECOM_M_XT3URBK_00FB:
 80	case USB_DEVICE_ID_ELECOM_M_XT3URBK_018F:
 81	case USB_DEVICE_ID_ELECOM_M_XT3DRBK_00FC:
 82	case USB_DEVICE_ID_ELECOM_M_XT4DRBK:
 83		/*
 84		 * Report descriptor format:
 85		 * 12: button bit count
 86		 * 30: padding bit count
 87		 * 14: button report size
 88		 * 20: button usage maximum
 89		 */
 90		mouse_button_fixup(hdev, rdesc, *rsize, 12, 30, 14, 20, 6);
 91		break;
 92	case USB_DEVICE_ID_ELECOM_M_DT1URBK:
 93	case USB_DEVICE_ID_ELECOM_M_DT1DRBK:
 94	case USB_DEVICE_ID_ELECOM_M_HT1URBK_010C:
 95	case USB_DEVICE_ID_ELECOM_M_HT1URBK_019B:
 96	case USB_DEVICE_ID_ELECOM_M_HT1DRBK_010D:
 97		/*
 98		 * Report descriptor format:
 99		 * 12: button bit count
100		 * 30: padding bit count
101		 * 14: button report size
102		 * 20: button usage maximum
103		 */
104		mouse_button_fixup(hdev, rdesc, *rsize, 12, 30, 14, 20, 8);
105		break;
106	case USB_DEVICE_ID_ELECOM_M_XT3DRBK_018C:
107		/*
108		 * Report descriptor format:
109		 * 22: button bit count
110		 * 30: padding bit count
111		 * 24: button report size
112		 * 16: button usage maximum
113		 */
114		mouse_button_fixup(hdev, rdesc, *rsize, 22, 30, 24, 16, 6);
115		break;
116	case USB_DEVICE_ID_ELECOM_M_DT2DRBK:
117	case USB_DEVICE_ID_ELECOM_M_HT1DRBK_011C:
118		/*
119		 * Report descriptor format:
120		 * 22: button bit count
121		 * 30: padding bit count
122		 * 24: button report size
123		 * 16: button usage maximum
124		 */
125		mouse_button_fixup(hdev, rdesc, *rsize, 22, 30, 24, 16, 8);
126		break;
127	case USB_DEVICE_ID_ELECOM_M_HT1MRBK:
128	case USB_DEVICE_ID_ELECOM_M_HT1MRBK_01AB:
129	case USB_DEVICE_ID_ELECOM_M_HT1MRBK_01AC:
130		/*
131		 * Report descriptor format:
132		 * 24: button bit count
133		 * 28: padding bit count
134		 * 22: button report size
135		 * 16: button usage maximum
136		 */
137		mouse_button_fixup(hdev, rdesc, *rsize, 24, 28, 22, 16, 8);
138		break;
139	}
140	return rdesc;
141}
142
143static const struct hid_device_id elecom_devices[] = {
144	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_BM084) },
145	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1MRBK_01AC) },
146	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XGL20DLBK) },
147	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3URBK_00FB) },
148	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3URBK_018F) },
149	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3DRBK_00FC) },
150	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3DRBK_018C) },
151	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT4DRBK) },
152	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT1URBK) },
153	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT1DRBK) },
154	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT2DRBK) },
155	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1URBK_010C) },
156	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1URBK_019B) },
157	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1DRBK_010D) },
158	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1DRBK_011C) },
159	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1MRBK) },
160	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1MRBK_01AB) },
161	{ }
162};
163MODULE_DEVICE_TABLE(hid, elecom_devices);
164
165static struct hid_driver elecom_driver = {
166	.name = "elecom",
167	.id_table = elecom_devices,
168	.report_fixup = elecom_report_fixup
169};
170module_hid_driver(elecom_driver);
171
172MODULE_DESCRIPTION("HID driver for ELECOM devices");
173MODULE_LICENSE("GPL");