1*5c773007Smpi /* $OpenBSD: data.c,v 1.8 2014/06/04 12:13:30 mpi Exp $ */
27517eab2Snate /* $NetBSD: data.c,v 1.1 2001/12/28 17:45:26 augustss Exp $ */
3be8f1931Spvalchev
4be8f1931Spvalchev /*
5be8f1931Spvalchev * Copyright (c) 1999 Lennart Augustsson <augustss@netbsd.org>
6be8f1931Spvalchev * All rights reserved.
7be8f1931Spvalchev *
8be8f1931Spvalchev * Redistribution and use in source and binary forms, with or without
9be8f1931Spvalchev * modification, are permitted provided that the following conditions
10be8f1931Spvalchev * are met:
11be8f1931Spvalchev * 1. Redistributions of source code must retain the above copyright
12be8f1931Spvalchev * notice, this list of conditions and the following disclaimer.
13be8f1931Spvalchev * 2. Redistributions in binary form must reproduce the above copyright
14be8f1931Spvalchev * notice, this list of conditions and the following disclaimer in the
15be8f1931Spvalchev * documentation and/or other materials provided with the distribution.
16be8f1931Spvalchev *
17be8f1931Spvalchev * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18be8f1931Spvalchev * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19be8f1931Spvalchev * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20be8f1931Spvalchev * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21be8f1931Spvalchev * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22be8f1931Spvalchev * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23be8f1931Spvalchev * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24be8f1931Spvalchev * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25be8f1931Spvalchev * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26be8f1931Spvalchev * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27be8f1931Spvalchev * SUCH DAMAGE.
28be8f1931Spvalchev */
29be8f1931Spvalchev
30be8f1931Spvalchev #include <stdlib.h>
31be8f1931Spvalchev #include "usbhid.h"
32be8f1931Spvalchev
33b3eedbb4Smpi int32_t
hid_get_data(const void * p,const hid_item_t * h)34be8f1931Spvalchev hid_get_data(const void *p, const hid_item_t *h)
35be8f1931Spvalchev {
36b3eedbb4Smpi const uint8_t *buf;
37b3eedbb4Smpi uint32_t hpos;
38b3eedbb4Smpi uint32_t hsize;
39b3eedbb4Smpi uint32_t data;
40b3eedbb4Smpi int i, end, offs;
41be8f1931Spvalchev
42b3eedbb4Smpi buf = p;
43b3eedbb4Smpi
44*5c773007Smpi #if 0
45b3eedbb4Smpi /* Skip report ID byte. */
46b3eedbb4Smpi if (h->report_ID > 0)
47b3eedbb4Smpi buf++;
48*5c773007Smpi #endif
49b3eedbb4Smpi
50b3eedbb4Smpi hpos = h->pos; /* bit position of data */
51b3eedbb4Smpi hsize = h->report_size; /* bit length of data */
52b3eedbb4Smpi
53b3eedbb4Smpi /* Range check and limit */
54be8f1931Spvalchev if (hsize == 0)
55be8f1931Spvalchev return (0);
56b3eedbb4Smpi if (hsize > 32)
57b3eedbb4Smpi hsize = 32;
58b3eedbb4Smpi
59be8f1931Spvalchev offs = hpos / 8;
60be8f1931Spvalchev end = (hpos + hsize) / 8 - offs;
61be8f1931Spvalchev data = 0;
62be8f1931Spvalchev for (i = 0; i <= end; i++)
63be8f1931Spvalchev data |= buf[offs + i] << (i*8);
64b3eedbb4Smpi
65b3eedbb4Smpi /* Correctly shift down data */
66be8f1931Spvalchev data >>= hpos % 8;
67b3eedbb4Smpi hsize = 32 - hsize;
68b3eedbb4Smpi
69b3eedbb4Smpi /* Mask and sign extend in one */
70b3eedbb4Smpi if ((h->logical_minimum < 0) || (h->logical_maximum < 0))
71b3eedbb4Smpi data = (int32_t)((int32_t)data << hsize) >> hsize;
72b3eedbb4Smpi else
73b3eedbb4Smpi data = (uint32_t)((uint32_t)data << hsize) >> hsize;
74b3eedbb4Smpi
75be8f1931Spvalchev return (data);
76be8f1931Spvalchev }
77be8f1931Spvalchev
78be8f1931Spvalchev void
hid_set_data(void * p,const hid_item_t * h,int32_t data)79b3eedbb4Smpi hid_set_data(void *p, const hid_item_t *h, int32_t data)
80be8f1931Spvalchev {
81b3eedbb4Smpi uint8_t *buf;
82b3eedbb4Smpi uint32_t hpos;
83b3eedbb4Smpi uint32_t hsize;
84b3eedbb4Smpi uint32_t mask;
85b3eedbb4Smpi int i;
86b3eedbb4Smpi int end;
87b3eedbb4Smpi int offs;
88b3eedbb4Smpi
89b3eedbb4Smpi buf = p;
90b3eedbb4Smpi
91*5c773007Smpi #if 0
92b3eedbb4Smpi /* Set report ID byte. */
93b3eedbb4Smpi if (h->report_ID > 0)
94b3eedbb4Smpi *buf++ = h->report_ID & 0xff;
95*5c773007Smpi #endif
96b3eedbb4Smpi
97b3eedbb4Smpi hpos = h->pos; /* bit position of data */
98b3eedbb4Smpi hsize = h->report_size; /* bit length of data */
99be8f1931Spvalchev
100be8f1931Spvalchev if (hsize != 32) {
101be8f1931Spvalchev mask = (1 << hsize) - 1;
102be8f1931Spvalchev data &= mask;
103be8f1931Spvalchev } else
104be8f1931Spvalchev mask = ~0;
105be8f1931Spvalchev
106be8f1931Spvalchev data <<= (hpos % 8);
107be8f1931Spvalchev mask <<= (hpos % 8);
108be8f1931Spvalchev mask = ~mask;
109be8f1931Spvalchev
110be8f1931Spvalchev offs = hpos / 8;
111be8f1931Spvalchev end = (hpos + hsize) / 8 - offs;
112be8f1931Spvalchev
113be8f1931Spvalchev for (i = 0; i <= end; i++)
114be8f1931Spvalchev buf[offs + i] = (buf[offs + i] & (mask >> (i*8))) |
115be8f1931Spvalchev ((data >> (i*8)) & 0xff);
116be8f1931Spvalchev }
117