1 /* $OpenBSD: data.c,v 1.5 2012/07/12 10:17:43 yuo 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 uint8_t *buf; 37 uint32_t hpos, hsize, data; 38 int i, end, offs; 39 40 buf = p; 41 42 /* skip report ID byte */ 43 if (h->report_ID > 0) 44 buf++; 45 46 hpos = h->pos; /* bit position of data */ 47 hsize = h->report_size; /* bit length of data */ 48 49 if (hsize == 0) 50 return (0); 51 if (hsize > 32) 52 hsize = 32; 53 54 offs = hpos / 8; 55 end = (hpos + hsize) / 8 - offs; 56 data = 0; 57 for (i = 0; i <= end; i++) 58 data |= buf[offs + i] << (i*8); 59 60 /* Correctly shift down data */ 61 data >>= hpos % 8; 62 hsize = 32 - hsize; 63 64 /* Mask and sign extend in one */ 65 if ((h->logical_minimum < 0) || (h->logical_maximum < 0)) 66 data = (int32_t)((int32_t)data << hsize) >> hsize; 67 else 68 data = (uint32_t)((uint32_t)data << hsize) >> hsize; 69 70 return (data); 71 } 72 73 void 74 hid_set_data(void *p, const hid_item_t *h, int data) 75 { 76 uint32_t *buf; 77 uint32_t hpos, hsize; 78 int i, end, offs, mask; 79 80 buf = p; 81 82 /* Set report ID byte */ 83 if (h->report_ID > 0) 84 *buf++ = h->report_ID & 0xff; 85 86 hpos = h->pos; /* bit position of data */ 87 hsize = h->report_size; /* bit length of data */ 88 89 if (hsize != 32) { 90 mask = (1 << hsize) - 1; 91 data &= mask; 92 } else 93 mask = ~0; 94 95 data <<= (hpos % 8); 96 mask <<= (hpos % 8); 97 mask = ~mask; 98 99 offs = hpos / 8; 100 end = (hpos + hsize) / 8 - offs; 101 102 for (i = 0; i <= end; i++) 103 buf[offs + i] = (buf[offs + i] & (mask >> (i*8))) | 104 ((data >> (i*8)) & 0xff); 105 } 106