sys/dev/onewire/onewire_subr.c

   1 /* $NetBSD: onewire_subr.c,v 1.5 2006/11/16 01:33:08 christos Exp $ */
   2 /*      $OpenBSD: onewire_subr.c,v 1.1 2006/03/04 16:27:03 grange Exp $ */
   3
   4 /*
   5  * Copyright (c) 2006 Alexander Yurchenko <grange@openbsd.org>
   6  *
   7  * Permission to use, copy, modify, and distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 /*
  21  * 1-Wire bus miscellaneous routines.
  22  */
  23
  24 #include <sys/cdefs.h>
  25 __KERNEL_RCSID(0, "$NetBSD$");
  26
  27 #include <sys/param.h>
  28 #include <sys/systm.h>
  29 #include <sys/device.h>
  30
  31 #include <dev/onewire/onewiredevs.h>
  32 #include <dev/onewire/onewirereg.h>
  33 #include <dev/onewire/onewirevar.h>
  34
  35 #ifdef ONEWIREVERBOSE
  36 struct onewire_family {
  37         int             of_type;
  38         const char *    of_name;
  39 };
  40 #include <dev/onewire/onewiredevs_data.h>
  41 #endif
  42
  43 static const u_int8_t crctable[] = {
  44         0x00, 0x5e, 0xbc, 0xe2, 0x61, 0x3f, 0xdd, 0x83,
  45         0xc2, 0x9c, 0x7e, 0x20, 0xa3, 0xfd, 0x1f, 0x41,
  46         0x9d, 0xc3, 0x21, 0x7f, 0xfc, 0xa2, 0x40, 0x1e,
  47         0x5f, 0x01, 0xe3, 0xbd, 0x3e, 0x60, 0x82, 0xdc,
  48         0x23, 0x7d, 0x9f, 0xc1, 0x42, 0x1c, 0xfe, 0xa0,
  49         0xe1, 0xbf, 0x5d, 0x03, 0x80, 0xde, 0x3c, 0x62,
  50         0xbe, 0xe0, 0x02, 0x5c, 0xdf, 0x81, 0x63, 0x3d,
  51         0x7c, 0x22, 0xc0, 0x9e, 0x1d, 0x43, 0xa1, 0xff,
  52         0x46, 0x18, 0xfa, 0xa4, 0x27, 0x79, 0x9b, 0xc5,
  53         0x84, 0xda, 0x38, 0x66, 0xe5, 0xbb, 0x59, 0x07,
  54         0xdb, 0x85, 0x67, 0x39, 0xba, 0xe4, 0x06, 0x58,
  55         0x19, 0x47, 0xa5, 0xfb, 0x78, 0x26, 0xc4, 0x9a,
  56         0x65, 0x3b, 0xd9, 0x87, 0x04, 0x5a, 0xb8, 0xe6,
  57         0xa7, 0xf9, 0x1b, 0x45, 0xc6, 0x98, 0x7a, 0x24,
  58         0xf8, 0xa6, 0x44, 0x1a, 0x99, 0xc7, 0x25, 0x7b,
  59         0x3a, 0x64, 0x86, 0xd8, 0x5b, 0x05, 0xe7, 0xb9,
  60         0x8c, 0xd2, 0x30, 0x6e, 0xed, 0xb3, 0x51, 0x0f,
  61         0x4e, 0x10, 0xf2, 0xac, 0x2f, 0x71, 0x93, 0xcd,
  62         0x11, 0x4f, 0xad, 0xf3, 0x70, 0x2e, 0xcc, 0x92,
  63         0xd3, 0x8d, 0x6f, 0x31, 0xb2, 0xec, 0x0e, 0x50,
  64         0xaf, 0xf1, 0x13, 0x4d, 0xce, 0x90, 0x72, 0x2c,
  65         0x6d, 0x33, 0xd1, 0x8f, 0x0c, 0x52, 0xb0, 0xee,
  66         0x32, 0x6c, 0x8e, 0xd0, 0x53, 0x0d, 0xef, 0xb1,
  67         0xf0, 0xae, 0x4c, 0x12, 0x91, 0xcf, 0x2d, 0x73,
  68         0xca, 0x94, 0x76, 0x28, 0xab, 0xf5, 0x17, 0x49,
  69         0x08, 0x56, 0xb4, 0xea, 0x69, 0x37, 0xd5, 0x8b,
  70         0x57, 0x09, 0xeb, 0xb5, 0x36, 0x68, 0x8a, 0xd4,
  71         0x95, 0xcb, 0x29, 0x77, 0xf4, 0xaa, 0x48, 0x16,
  72         0xe9, 0xb7, 0x55, 0x0b, 0x88, 0xd6, 0x34, 0x6a,
  73         0x2b, 0x75, 0x97, 0xc9, 0x4a, 0x14, 0xf6, 0xa8,
  74         0x74, 0x2a, 0xc8, 0x96, 0x15, 0x4b, 0xa9, 0xf7,
  75         0xb6, 0xe8, 0x0a, 0x54, 0xd7, 0x89, 0x6b, 0x35
  76 };
  77
  78 int
  79 onewire_crc(const void *buf, int len)
  80 {
  81         const u_int8_t *p = buf;
  82         u_int8_t crc = 0;
  83
  84         while (len--)
  85                 crc = crctable[crc ^ *p++];
  86
  87         return (crc);
  88 }
  89
  90 const char *
  91 onewire_famname(int type)
  92 {
  93 #ifdef ONEWIREVERBOSE
  94         const struct onewire_family *of;
  95
  96         for (of = onewire_famtab; of->of_name != NULL; of++)
  97                 if (of->of_type == type)
  98                         return (of->of_name);
  99 #endif
 100
 101         return (NULL);
 102 }
 103
 104 int
 105 onewire_matchbyfam(struct onewire_attach_args *oa,
 106     const struct onewire_matchfam *fams, int nent)
 107 {
 108         const struct onewire_matchfam *om;
 109         int i;
 110
 111         for (i = 0, om = fams; i < nent; i++, om++)
 112                 if (ONEWIRE_ROM_FAMILY_TYPE(oa->oa_rom) == om->om_type)
 113                         return (1);
 114
 115         return (0);
 116 }