1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *  HID driver for ViewSonic devices not fully compliant with HID standard
4  *
5  *  Copyright (c) 2017 Nikolai Kondrashov
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 /* Size of the original descriptor of PD1011 signature pad */
22 #define PD1011_RDESC_ORIG_SIZE	408
23 
24 /* Fixed report descriptor of PD1011 signature pad */
25 static __u8 pd1011_rdesc_fixed[] = {
26 	0x05, 0x0D,             /*  Usage Page (Digitizer),             */
27 	0x09, 0x01,             /*  Usage (Digitizer),                  */
28 	0xA1, 0x01,             /*  Collection (Application),           */
29 	0x85, 0x02,             /*      Report ID (2),                  */
30 	0x09, 0x20,             /*      Usage (Stylus),                 */
31 	0xA0,                   /*      Collection (Physical),          */
32 	0x75, 0x10,             /*          Report Size (16),           */
33 	0x95, 0x01,             /*          Report Count (1),           */
34 	0xA4,                   /*          Push,                       */
35 	0x05, 0x01,             /*          Usage Page (Desktop),       */
36 	0x65, 0x13,             /*          Unit (Inch),                */
37 	0x55, 0xFD,             /*          Unit Exponent (-3),         */
38 	0x34,                   /*          Physical Minimum (0),       */
39 	0x09, 0x30,             /*          Usage (X),                  */
40 	0x46, 0x5D, 0x21,       /*          Physical Maximum (8541),    */
41 	0x27, 0x80, 0xA9,
42 		0x00, 0x00,     /*          Logical Maximum (43392),    */
43 	0x81, 0x02,             /*          Input (Variable),           */
44 	0x09, 0x31,             /*          Usage (Y),                  */
45 	0x46, 0xDA, 0x14,       /*          Physical Maximum (5338),    */
46 	0x26, 0xF0, 0x69,       /*          Logical Maximum (27120),    */
47 	0x81, 0x02,             /*          Input (Variable),           */
48 	0xB4,                   /*          Pop,                        */
49 	0x14,                   /*          Logical Minimum (0),        */
50 	0x25, 0x01,             /*          Logical Maximum (1),        */
51 	0x75, 0x01,             /*          Report Size (1),            */
52 	0x95, 0x01,             /*          Report Count (1),           */
53 	0x81, 0x03,             /*          Input (Constant, Variable), */
54 	0x09, 0x32,             /*          Usage (In Range),           */
55 	0x09, 0x42,             /*          Usage (Tip Switch),         */
56 	0x95, 0x02,             /*          Report Count (2),           */
57 	0x81, 0x02,             /*          Input (Variable),           */
58 	0x95, 0x05,             /*          Report Count (5),           */
59 	0x81, 0x03,             /*          Input (Constant, Variable), */
60 	0x75, 0x10,             /*          Report Size (16),           */
61 	0x95, 0x01,             /*          Report Count (1),           */
62 	0x09, 0x30,             /*          Usage (Tip Pressure),       */
63 	0x15, 0x05,             /*          Logical Minimum (5),        */
64 	0x26, 0xFF, 0x07,       /*          Logical Maximum (2047),     */
65 	0x81, 0x02,             /*          Input (Variable),           */
66 	0x75, 0x10,             /*          Report Size (16),           */
67 	0x95, 0x01,             /*          Report Count (1),           */
68 	0x81, 0x03,             /*          Input (Constant, Variable), */
69 	0xC0,                   /*      End Collection,                 */
70 	0xC0                    /*  End Collection                      */
71 };
72 
viewsonic_report_fixup(struct hid_device * hdev,__u8 * rdesc,unsigned int * rsize)73 static __u8 *viewsonic_report_fixup(struct hid_device *hdev, __u8 *rdesc,
74 				    unsigned int *rsize)
75 {
76 	switch (hdev->product) {
77 	case USB_DEVICE_ID_VIEWSONIC_PD1011:
78 	case USB_DEVICE_ID_SIGNOTEC_VIEWSONIC_PD1011:
79 		if (*rsize == PD1011_RDESC_ORIG_SIZE) {
80 			rdesc = pd1011_rdesc_fixed;
81 			*rsize = sizeof(pd1011_rdesc_fixed);
82 		}
83 		break;
84 	}
85 
86 	return rdesc;
87 }
88 
89 static const struct hid_device_id viewsonic_devices[] = {
90 	{ HID_USB_DEVICE(USB_VENDOR_ID_VIEWSONIC,
91 				USB_DEVICE_ID_VIEWSONIC_PD1011) },
92 	{ HID_USB_DEVICE(USB_VENDOR_ID_SIGNOTEC,
93 				USB_DEVICE_ID_SIGNOTEC_VIEWSONIC_PD1011) },
94 	{ }
95 };
96 MODULE_DEVICE_TABLE(hid, viewsonic_devices);
97 
98 static struct hid_driver viewsonic_driver = {
99 	.name = "viewsonic",
100 	.id_table = viewsonic_devices,
101 	.report_fixup = viewsonic_report_fixup,
102 };
103 module_hid_driver(viewsonic_driver);
104 
105 MODULE_LICENSE("GPL");
106