fbmem: don't allow too huge resolutions
[linux-2.6-microblaze.git] / drivers / hid / 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  *
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
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
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");