xref: /linux/drivers/hid/hid-elecom.c (revision b8e5fdf0bd022cd5493a5987ef66f5a24f8352d8)
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
37 static 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 
57 static 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 
143 static 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 };
163 MODULE_DEVICE_TABLE(hid, elecom_devices);
164 
165 static struct hid_driver elecom_driver = {
166 	.name = "elecom",
167 	.id_table = elecom_devices,
168 	.report_fixup = elecom_report_fixup
169 };
170 module_hid_driver(elecom_driver);
171 
172 MODULE_DESCRIPTION("HID driver for ELECOM devices");
173 MODULE_LICENSE("GPL");
174