xref: /freebsd/lib/libusbhid/data.c (revision 1843dfb05ed80149f5a412180af882e3cb8f451b)
1 /*	$NetBSD: data.c,v 1.8 2000/04/02 11:10:53 augustss Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-2-Clause
5  *
6  * Copyright (c) 1999 Lennart Augustsson <augustss@netbsd.org>
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 #include <sys/param.h>
33 #include <assert.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <dev/usb/usb_ioctl.h>
37 #include "usbhid.h"
38 #include "usbvar.h"
39 
40 int32_t
41 hid_get_data(const void *p, const hid_item_t *h)
42 {
43 	const uint8_t *buf;
44 	uint32_t hpos;
45 	uint32_t hsize;
46 	uint32_t data;
47 	int i, end, offs;
48 
49 	buf = p;
50 
51 	/* Skip report ID byte. */
52 	if (h->report_ID > 0)
53 		buf++;
54 
55 	hpos = h->pos;			/* bit position of data */
56 	hsize = h->report_size;		/* bit length of data */
57 
58 	/* Range check and limit */
59 	if (hsize == 0)
60 		return (0);
61 	if (hsize > 32)
62 		hsize = 32;
63 
64 	offs = hpos / 8;
65 	end = (hpos + hsize) / 8 - offs;
66 	data = 0;
67 	for (i = 0; i <= end; i++)
68 		data |= buf[offs + i] << (i*8);
69 
70 	/* Correctly shift down data */
71 	data >>= hpos % 8;
72 	hsize = 32 - hsize;
73 
74 	/* Mask and sign extend in one */
75 	if ((h->logical_minimum < 0) || (h->logical_maximum < 0))
76 		data = (int32_t)((int32_t)data << hsize) >> hsize;
77 	else
78 		data = (uint32_t)((uint32_t)data << hsize) >> hsize;
79 
80 	return (data);
81 }
82 
83 void
84 hid_set_data(void *p, const hid_item_t *h, int32_t data)
85 {
86 	uint8_t *buf;
87 	uint32_t hpos;
88 	uint32_t hsize;
89 	uint32_t mask;
90 	int i;
91 	int end;
92 	int offs;
93 
94 	buf = p;
95 
96 	/* Set report ID byte. */
97 	if (h->report_ID > 0)
98 		*buf++ = h->report_ID & 0xff;
99 
100 	hpos = h->pos;			/* bit position of data */
101 	hsize = h->report_size;		/* bit length of data */
102 
103 	if (hsize != 32) {
104 		mask = (1 << hsize) - 1;
105 		data &= mask;
106 	} else
107 		mask = ~0;
108 
109 	data <<= (hpos % 8);
110 	mask <<= (hpos % 8);
111 	mask = ~mask;
112 
113 	offs = hpos / 8;
114 	end = (hpos + hsize) / 8 - offs;
115 
116 	for (i = 0; i <= end; i++)
117 		buf[offs + i] = (buf[offs + i] & (mask >> (i*8))) |
118 		    ((data >> (i*8)) & 0xff);
119 }
120 
121 int
122 hid_get_report(int fd, enum hid_kind k, unsigned char *data, unsigned int size)
123 {
124 	struct usb_gen_descriptor ugd;
125 
126 	memset(&ugd, 0, sizeof(ugd));
127 	ugd.ugd_data = data;
128 	ugd.ugd_maxlen = size;
129 	ugd.ugd_report_type = k + 1;
130 	return (ioctl(fd, USB_GET_REPORT, &ugd));
131 }
132 
133 int
134 hid_set_report(int fd, enum hid_kind k, unsigned char *data, unsigned int size)
135 {
136 	struct usb_gen_descriptor ugd;
137 
138 	memset(&ugd, 0, sizeof(ugd));
139 	ugd.ugd_data = data;
140 	ugd.ugd_maxlen = size;
141 	ugd.ugd_report_type = k + 1;
142 	return (ioctl(fd, USB_SET_REPORT, &ugd));
143 }
144