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
mouse_button_fixup(struct hid_device * hdev,__u8 * rdesc,unsigned int rsize,unsigned int button_bit_count,unsigned int padding_bit,unsigned int button_report_size,unsigned int button_usage_maximum,int nbuttons)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
elecom_report_fixup(struct hid_device * hdev,__u8 * rdesc,unsigned int * rsize)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");
128