1 /* $OpenBSD: data.c,v 1.1 2001/12/30 07:04:38 pvalchev Exp $ */ 2 /* $NetBSD: data.c,v 1.8 2000/04/02 11:10:53 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 34 hid_get_data(const void *p, const hid_item_t *h) 35 { 36 const unsigned char *buf; 37 unsigned int hpos; 38 unsigned int hsize; 39 int data; 40 int i, end, offs; 41 42 buf = p; 43 hpos = h->pos; /* bit position of data */ 44 hsize = h->report_size; /* bit length of data */ 45 46 if (hsize == 0) 47 return (0); 48 offs = hpos / 8; 49 end = (hpos + hsize) / 8 - offs; 50 data = 0; 51 for (i = 0; i <= end; i++) 52 data |= buf[offs + i] << (i*8); 53 data >>= hpos % 8; 54 data &= (1 << hsize) - 1; 55 if (h->logical_minimum < 0) { 56 /* Need to sign extend */ 57 hsize = sizeof data * 8 - hsize; 58 data = (data << hsize) >> hsize; 59 } 60 return (data); 61 } 62 63 void 64 hid_set_data(void *p, const hid_item_t *h, int data) 65 { 66 unsigned char *buf; 67 unsigned int hpos; 68 unsigned int hsize; 69 int i, end, offs, mask; 70 71 buf = p; 72 hpos = h->pos; /* bit position of data */ 73 hsize = h->report_size; /* bit length of data */ 74 75 if (hsize != 32) { 76 mask = (1 << hsize) - 1; 77 data &= mask; 78 } else 79 mask = ~0; 80 81 data <<= (hpos % 8); 82 mask <<= (hpos % 8); 83 mask = ~mask; 84 85 offs = hpos / 8; 86 end = (hpos + hsize) / 8 - offs; 87 88 for (i = 0; i <= end; i++) 89 buf[offs + i] = (buf[offs + i] & (mask >> (i*8))) | 90 ((data >> (i*8)) & 0xff); 91 } 92