1 /* $OpenBSD: onewire_subr.c,v 1.2 2007/02/28 22:31:32 deraadt Exp $ */ 2 3 /* 4 * Copyright (c) 2006 Alexander Yurchenko <grange@openbsd.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 /* 20 * 1-Wire bus miscellaneous routines. 21 */ 22 23 #include <sys/param.h> 24 #include <sys/systm.h> 25 #include <sys/device.h> 26 27 #include <dev/onewire/onewiredevs.h> 28 #include <dev/onewire/onewirereg.h> 29 #include <dev/onewire/onewirevar.h> 30 31 #ifdef ONEWIREVERBOSE 32 #include <dev/onewire/onewiredevs_data.h> 33 #endif 34 35 static const u_int8_t crctable[] = { 36 0x00, 0x5e, 0xbc, 0xe2, 0x61, 0x3f, 0xdd, 0x83, 37 0xc2, 0x9c, 0x7e, 0x20, 0xa3, 0xfd, 0x1f, 0x41, 38 0x9d, 0xc3, 0x21, 0x7f, 0xfc, 0xa2, 0x40, 0x1e, 39 0x5f, 0x01, 0xe3, 0xbd, 0x3e, 0x60, 0x82, 0xdc, 40 0x23, 0x7d, 0x9f, 0xc1, 0x42, 0x1c, 0xfe, 0xa0, 41 0xe1, 0xbf, 0x5d, 0x03, 0x80, 0xde, 0x3c, 0x62, 42 0xbe, 0xe0, 0x02, 0x5c, 0xdf, 0x81, 0x63, 0x3d, 43 0x7c, 0x22, 0xc0, 0x9e, 0x1d, 0x43, 0xa1, 0xff, 44 0x46, 0x18, 0xfa, 0xa4, 0x27, 0x79, 0x9b, 0xc5, 45 0x84, 0xda, 0x38, 0x66, 0xe5, 0xbb, 0x59, 0x07, 46 0xdb, 0x85, 0x67, 0x39, 0xba, 0xe4, 0x06, 0x58, 47 0x19, 0x47, 0xa5, 0xfb, 0x78, 0x26, 0xc4, 0x9a, 48 0x65, 0x3b, 0xd9, 0x87, 0x04, 0x5a, 0xb8, 0xe6, 49 0xa7, 0xf9, 0x1b, 0x45, 0xc6, 0x98, 0x7a, 0x24, 50 0xf8, 0xa6, 0x44, 0x1a, 0x99, 0xc7, 0x25, 0x7b, 51 0x3a, 0x64, 0x86, 0xd8, 0x5b, 0x05, 0xe7, 0xb9, 52 0x8c, 0xd2, 0x30, 0x6e, 0xed, 0xb3, 0x51, 0x0f, 53 0x4e, 0x10, 0xf2, 0xac, 0x2f, 0x71, 0x93, 0xcd, 54 0x11, 0x4f, 0xad, 0xf3, 0x70, 0x2e, 0xcc, 0x92, 55 0xd3, 0x8d, 0x6f, 0x31, 0xb2, 0xec, 0x0e, 0x50, 56 0xaf, 0xf1, 0x13, 0x4d, 0xce, 0x90, 0x72, 0x2c, 57 0x6d, 0x33, 0xd1, 0x8f, 0x0c, 0x52, 0xb0, 0xee, 58 0x32, 0x6c, 0x8e, 0xd0, 0x53, 0x0d, 0xef, 0xb1, 59 0xf0, 0xae, 0x4c, 0x12, 0x91, 0xcf, 0x2d, 0x73, 60 0xca, 0x94, 0x76, 0x28, 0xab, 0xf5, 0x17, 0x49, 61 0x08, 0x56, 0xb4, 0xea, 0x69, 0x37, 0xd5, 0x8b, 62 0x57, 0x09, 0xeb, 0xb5, 0x36, 0x68, 0x8a, 0xd4, 63 0x95, 0xcb, 0x29, 0x77, 0xf4, 0xaa, 0x48, 0x16, 64 0xe9, 0xb7, 0x55, 0x0b, 0x88, 0xd6, 0x34, 0x6a, 65 0x2b, 0x75, 0x97, 0xc9, 0x4a, 0x14, 0xf6, 0xa8, 66 0x74, 0x2a, 0xc8, 0x96, 0x15, 0x4b, 0xa9, 0xf7, 67 0xb6, 0xe8, 0x0a, 0x54, 0xd7, 0x89, 0x6b, 0x35 68 }; 69 70 int 71 onewire_crc(const void *buf, int len) 72 { 73 const u_int8_t *p = buf; 74 u_int8_t crc = 0; 75 76 while (len--) 77 crc = crctable[crc ^ *p++]; 78 79 return (crc); 80 } 81 82 const char * 83 onewire_famname(int type) 84 { 85 #ifdef ONEWIREVERBOSE 86 const struct onewire_family *of; 87 88 for (of = onewire_famtab; of->of_name != NULL; of++) 89 if (of->of_type == type) 90 return (of->of_name); 91 #endif 92 93 return (NULL); 94 } 95 96 int 97 onewire_matchbyfam(struct onewire_attach_args *oa, 98 const struct onewire_matchfam *fams, int nent) 99 { 100 const struct onewire_matchfam *om; 101 int i; 102 103 for (i = 0, om = fams; i < nent; i++, om++) 104 if (ONEWIRE_ROM_FAMILY_TYPE(oa->oa_rom) == om->om_type) 105 return (1); 106 107 return (0); 108 } 109