1 /* $OpenBSD: data.c,v 1.3 2004/06/04 00:47:32 deraadt Exp $ */
2 /* $NetBSD: data.c,v 1.1 2001/12/28 17:45:26 augustss Exp $ */
3
4 /*
5 * Copyright (c) 1999 Lennart Augustsson <augustss@netbsd.org>
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include <stdlib.h>
31 #include "usbhid.h"
32
33 int
hid_get_data(const void * p,const hid_item_t * h)34 hid_get_data(const void *p, const hid_item_t *h)
35 {
36 const unsigned char *buf = p;
37 unsigned int hpos = h->pos, hsize = h->report_size;
38 int data, i, end, offs;
39
40 if (hsize == 0)
41 return (0);
42 offs = hpos / 8;
43 end = (hpos + hsize) / 8 - offs;
44 data = 0;
45 for (i = 0; i <= end; i++)
46 data |= buf[offs + i] << (i*8);
47 data >>= hpos % 8;
48 data &= (1 << hsize) - 1;
49 if (h->logical_minimum < 0) {
50 /* Need to sign extend */
51 hsize = sizeof data * 8 - hsize;
52 data = (data << hsize) >> hsize;
53 }
54 return (data);
55 }
56
57 void
hid_set_data(void * p,const hid_item_t * h,int data)58 hid_set_data(void *p, const hid_item_t *h, int data)
59 {
60 unsigned char *buf = p;
61 unsigned int hpos = h->pos, hsize = h->report_size;
62 int i, end, offs, mask;
63
64 if (hsize != 32) {
65 mask = (1 << hsize) - 1;
66 data &= mask;
67 } else
68 mask = ~0;
69
70 data <<= (hpos % 8);
71 mask <<= (hpos % 8);
72 mask = ~mask;
73
74 offs = hpos / 8;
75 end = (hpos + hsize) / 8 - offs;
76
77 for (i = 0; i <= end; i++)
78 buf[offs + i] = (buf[offs + i] & (mask >> (i*8))) |
79 ((data >> (i*8)) & 0xff);
80 }
81