xref: /openbmc/linux/drivers/hid/hid-elecom.c (revision 5a244f48)
1 /*
2  *  HID driver for ELECOM devices.
3  *  Copyright (c) 2010 Richard Nauber <Richard.Nauber@gmail.com>
4  *  Copyright (c) 2016 Yuxuan Shui <yshuiv7@gmail.com>
5  *  Copyright (c) 2017 Diego Elio Pettenò <flameeyes@flameeyes.eu>
6  */
7 
8 /*
9  * This program is free software; you can redistribute it and/or modify it
10  * under the terms of the GNU General Public License as published by the Free
11  * Software Foundation; either version 2 of the License, or (at your option)
12  * any later version.
13  */
14 
15 #include <linux/device.h>
16 #include <linux/hid.h>
17 #include <linux/module.h>
18 
19 #include "hid-ids.h"
20 
21 static __u8 *elecom_report_fixup(struct hid_device *hdev, __u8 *rdesc,
22 		unsigned int *rsize)
23 {
24 	switch (hdev->product) {
25 	case USB_DEVICE_ID_ELECOM_BM084:
26 		/* The BM084 Bluetooth mouse includes a non-existing horizontal
27 		 * wheel in the HID descriptor. */
28 		if (*rsize >= 48 && rdesc[46] == 0x05 && rdesc[47] == 0x0c) {
29 			hid_info(hdev, "Fixing up Elecom BM084 report descriptor\n");
30 			rdesc[47] = 0x00;
31 		}
32 		break;
33 	case USB_DEVICE_ID_ELECOM_DEFT_WIRED:
34 	case USB_DEVICE_ID_ELECOM_DEFT_WIRELESS:
35 		/* The DEFT trackball has eight buttons, but its descriptor only
36 		 * reports five, disabling the three Fn buttons on the top of
37 		 * the mouse.
38 		 *
39 		 * Apply the following diff to the descriptor:
40 		 *
41 		 * Collection (Physical),              Collection (Physical),
42 		 *     Report ID (1),                      Report ID (1),
43 		 *     Report Count (5),           ->      Report Count (8),
44 		 *     Report Size (1),                    Report Size (1),
45 		 *     Usage Page (Button),                Usage Page (Button),
46 		 *     Usage Minimum (01h),                Usage Minimum (01h),
47 		 *     Usage Maximum (05h),        ->      Usage Maximum (08h),
48 		 *     Logical Minimum (0),                Logical Minimum (0),
49 		 *     Logical Maximum (1),                Logical Maximum (1),
50 		 *     Input (Variable),                   Input (Variable),
51 		 *     Report Count (1),           ->      Report Count (0),
52 		 *     Report Size (3),                    Report Size (3),
53 		 *     Input (Constant),                   Input (Constant),
54 		 *     Report Size (16),                   Report Size (16),
55 		 *     Report Count (2),                   Report Count (2),
56 		 *     Usage Page (Desktop),               Usage Page (Desktop),
57 		 *     Usage (X),                          Usage (X),
58 		 *     Usage (Y),                          Usage (Y),
59 		 *     Logical Minimum (-32768),           Logical Minimum (-32768),
60 		 *     Logical Maximum (32767),            Logical Maximum (32767),
61 		 *     Input (Variable, Relative),         Input (Variable, Relative),
62 		 * End Collection,                     End Collection,
63 		 */
64 		if (*rsize == 213 && rdesc[13] == 5 && rdesc[21] == 5) {
65 			hid_info(hdev, "Fixing up Elecom DEFT Fn buttons\n");
66 			rdesc[13] = 8; /* Button/Variable Report Count */
67 			rdesc[21] = 8; /* Button/Variable Usage Maximum */
68 			rdesc[29] = 0; /* Button/Constant Report Count */
69 		}
70 		break;
71 	}
72 	return rdesc;
73 }
74 
75 static const struct hid_device_id elecom_devices[] = {
76 	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_BM084) },
77 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_DEFT_WIRED) },
78 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_DEFT_WIRELESS) },
79 	{ }
80 };
81 MODULE_DEVICE_TABLE(hid, elecom_devices);
82 
83 static struct hid_driver elecom_driver = {
84 	.name = "elecom",
85 	.id_table = elecom_devices,
86 	.report_fixup = elecom_report_fixup
87 };
88 module_hid_driver(elecom_driver);
89 
90 MODULE_LICENSE("GPL");
91