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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
36static 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
56static const __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_00FB:
79 case USB_DEVICE_ID_ELECOM_M_XT3URBK_018F:
80 case USB_DEVICE_ID_ELECOM_M_XT3DRBK_00FC:
81 case USB_DEVICE_ID_ELECOM_M_XT4DRBK:
82 /*
83 * Report descriptor format:
84 * 12: button bit count
85 * 30: padding bit count
86 * 14: button report size
87 * 20: button usage maximum
88 */
89 mouse_button_fixup(hdev, rdesc, *rsize, 12, 30, 14, 20, 6);
90 break;
91 case USB_DEVICE_ID_ELECOM_M_DT1URBK:
92 case USB_DEVICE_ID_ELECOM_M_DT1DRBK:
93 case USB_DEVICE_ID_ELECOM_M_HT1URBK_010C:
94 case USB_DEVICE_ID_ELECOM_M_HT1URBK_019B:
95 case USB_DEVICE_ID_ELECOM_M_HT1DRBK_010D:
96 /*
97 * Report descriptor format:
98 * 12: button bit count
99 * 30: padding bit count
100 * 14: button report size
101 * 20: button usage maximum
102 */
103 mouse_button_fixup(hdev, rdesc, *rsize, 12, 30, 14, 20, 8);
104 break;
105 case USB_DEVICE_ID_ELECOM_M_XT3DRBK_018C:
106 /*
107 * Report descriptor format:
108 * 22: button bit count
109 * 30: padding bit count
110 * 24: button report size
111 * 16: button usage maximum
112 */
113 mouse_button_fixup(hdev, rdesc, *rsize, 22, 30, 24, 16, 6);
114 break;
115 case USB_DEVICE_ID_ELECOM_M_DT2DRBK:
116 case USB_DEVICE_ID_ELECOM_M_HT1DRBK_011C:
117 /*
118 * Report descriptor format:
119 * 22: button bit count
120 * 30: padding bit count
121 * 24: button report size
122 * 16: button usage maximum
123 */
124 mouse_button_fixup(hdev, rdesc, *rsize, 22, 30, 24, 16, 8);
125 break;
126 }
127 return rdesc;
128}
129
130static const struct hid_device_id elecom_devices[] = {
131 { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_BM084) },
132 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XGL20DLBK) },
133 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3URBK_00FB) },
134 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3URBK_018F) },
135 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3DRBK_00FC) },
136 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3DRBK_018C) },
137 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT4DRBK) },
138 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT1URBK) },
139 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT1DRBK) },
140 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT2DRBK) },
141 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1URBK_010C) },
142 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1URBK_019B) },
143 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1DRBK_010D) },
144 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1DRBK_011C) },
145 { }
146};
147MODULE_DEVICE_TABLE(hid, elecom_devices);
148
149static struct hid_driver elecom_driver = {
150 .name = "elecom",
151 .id_table = elecom_devices,
152 .report_fixup = elecom_report_fixup
153};
154module_hid_driver(elecom_driver);
155
156MODULE_DESCRIPTION("HID driver for ELECOM devices");
157MODULE_LICENSE("GPL");