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 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 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