release/src/router/apcupsd/src/libusbhid/data.c

   1 /*      $NetBSD: data.c,v 1.8 2000/04/02 11:10:53 augustss Exp $        */
   2
   3 /*
   4  * Copyright (c) 1999 Lennart Augustsson <augustss@netbsd.org>
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <assert.h>
  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 = (const unsigned char *)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 &= (1ULL << 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 = (unsigned char *)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 }