/*      $OpenBSD: onewire_subr.c,v 1.4 2010/07/19 23:44:09 deraadt Exp $        */

/*
 * Copyright (c) 2006 Alexander Yurchenko <grange@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * 1-Wire bus miscellaneous routines.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>

#include <dev/onewire/onewiredevs.h>
#include <dev/onewire/onewirereg.h>
#include <dev/onewire/onewirevar.h>

#ifdef ONEWIREVERBOSE
#include <dev/onewire/onewiredevs_data.h>
#endif

static const u_int8_t crc8_table[] = {
        0x00, 0x5e, 0xbc, 0xe2, 0x61, 0x3f, 0xdd, 0x83,
        0xc2, 0x9c, 0x7e, 0x20, 0xa3, 0xfd, 0x1f, 0x41,
        0x9d, 0xc3, 0x21, 0x7f, 0xfc, 0xa2, 0x40, 0x1e,
        0x5f, 0x01, 0xe3, 0xbd, 0x3e, 0x60, 0x82, 0xdc,
        0x23, 0x7d, 0x9f, 0xc1, 0x42, 0x1c, 0xfe, 0xa0,
        0xe1, 0xbf, 0x5d, 0x03, 0x80, 0xde, 0x3c, 0x62,
        0xbe, 0xe0, 0x02, 0x5c, 0xdf, 0x81, 0x63, 0x3d,
        0x7c, 0x22, 0xc0, 0x9e, 0x1d, 0x43, 0xa1, 0xff,
        0x46, 0x18, 0xfa, 0xa4, 0x27, 0x79, 0x9b, 0xc5,
        0x84, 0xda, 0x38, 0x66, 0xe5, 0xbb, 0x59, 0x07,
        0xdb, 0x85, 0x67, 0x39, 0xba, 0xe4, 0x06, 0x58,
        0x19, 0x47, 0xa5, 0xfb, 0x78, 0x26, 0xc4, 0x9a,
        0x65, 0x3b, 0xd9, 0x87, 0x04, 0x5a, 0xb8, 0xe6,
        0xa7, 0xf9, 0x1b, 0x45, 0xc6, 0x98, 0x7a, 0x24,
        0xf8, 0xa6, 0x44, 0x1a, 0x99, 0xc7, 0x25, 0x7b,
        0x3a, 0x64, 0x86, 0xd8, 0x5b, 0x05, 0xe7, 0xb9,
        0x8c, 0xd2, 0x30, 0x6e, 0xed, 0xb3, 0x51, 0x0f,
        0x4e, 0x10, 0xf2, 0xac, 0x2f, 0x71, 0x93, 0xcd,
        0x11, 0x4f, 0xad, 0xf3, 0x70, 0x2e, 0xcc, 0x92,
        0xd3, 0x8d, 0x6f, 0x31, 0xb2, 0xec, 0x0e, 0x50,
        0xaf, 0xf1, 0x13, 0x4d, 0xce, 0x90, 0x72, 0x2c,
        0x6d, 0x33, 0xd1, 0x8f, 0x0c, 0x52, 0xb0, 0xee,
        0x32, 0x6c, 0x8e, 0xd0, 0x53, 0x0d, 0xef, 0xb1,
        0xf0, 0xae, 0x4c, 0x12, 0x91, 0xcf, 0x2d, 0x73,
        0xca, 0x94, 0x76, 0x28, 0xab, 0xf5, 0x17, 0x49,
        0x08, 0x56, 0xb4, 0xea, 0x69, 0x37, 0xd5, 0x8b,
        0x57, 0x09, 0xeb, 0xb5, 0x36, 0x68, 0x8a, 0xd4,
        0x95, 0xcb, 0x29, 0x77, 0xf4, 0xaa, 0x48, 0x16,
        0xe9, 0xb7, 0x55, 0x0b, 0x88, 0xd6, 0x34, 0x6a,
        0x2b, 0x75, 0x97, 0xc9, 0x4a, 0x14, 0xf6, 0xa8,
        0x74, 0x2a, 0xc8, 0x96, 0x15, 0x4b, 0xa9, 0xf7,
        0xb6, 0xe8, 0x0a, 0x54, 0xd7, 0x89, 0x6b, 0x35
};

static const u_int8_t crc16_table_low[] = {
        0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
        0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
        0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
        0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
        0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
        0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
        0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
        0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
        0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
        0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
        0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
        0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
        0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
        0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
        0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
        0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
        0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
        0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
        0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
        0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
        0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
        0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
        0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
        0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
        0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
        0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
        0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
        0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
        0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
        0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
        0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
        0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40
};

static const u_int8_t crc16_table_high[] = {
        0x00, 0xc0, 0xc1, 0x01, 0xc3, 0x03, 0x02, 0xc2,
        0xc6, 0x06, 0x07, 0xc7, 0x05, 0xc5, 0xc4, 0x04,
        0xcc, 0x0c, 0x0d, 0xcd, 0x0f, 0xcf, 0xce, 0x0e,
        0x0a, 0xca, 0xcb, 0x0b, 0xc9, 0x09, 0x08, 0xc8,
        0xd8, 0x18, 0x19, 0xd9, 0x1b, 0xdb, 0xda, 0x1a,
        0x1e, 0xde, 0xdf, 0x1f, 0xdd, 0x1d, 0x1c, 0xdc,
        0x14, 0xd4, 0xd5, 0x15, 0xd7, 0x17, 0x16, 0xd6,
        0xd2, 0x12, 0x13, 0xd3, 0x11, 0xd1, 0xd0, 0x10,
        0xf0, 0x30, 0x31, 0xf1, 0x33, 0xf3, 0xf2, 0x32,
        0x36, 0xf6, 0xf7, 0x37, 0xf5, 0x35, 0x34, 0xf4,
        0x3c, 0xfc, 0xfd, 0x3d, 0xff, 0x3f, 0x3e, 0xfe,
        0xfa, 0x3a, 0x3b, 0xfb, 0x39, 0xf9, 0xf8, 0x38,
        0x28, 0xe8, 0xe9, 0x29, 0xeb, 0x2b, 0x2a, 0xea,
        0xee, 0x2e, 0x2f, 0xef, 0x2d, 0xed, 0xec, 0x2c,
        0xe4, 0x24, 0x25, 0xe5, 0x27, 0xe7, 0xe6, 0x26,
        0x22, 0xe2, 0xe3, 0x23, 0xe1, 0x21, 0x20, 0xe0,
        0xa0, 0x60, 0x61, 0xa1, 0x63, 0xa3, 0xa2, 0x62,
        0x66, 0xa6, 0xa7, 0x67, 0xa5, 0x65, 0x64, 0xa4,
        0x6c, 0xac, 0xad, 0x6d, 0xaf, 0x6f, 0x6e, 0xae,
        0xaa, 0x6a, 0x6b, 0xab, 0x69, 0xa9, 0xa8, 0x68,
        0x78, 0xb8, 0xb9, 0x79, 0xbb, 0x7b, 0x7a, 0xba,
        0xbe, 0x7e, 0x7f, 0xbf, 0x7d, 0xbd, 0xbc, 0x7c,
        0xb4, 0x74, 0x75, 0xb5, 0x77, 0xb7, 0xb6, 0x76,
        0x72, 0xb2, 0xb3, 0x73, 0xb1, 0x71, 0x70, 0xb0,
        0x50, 0x90, 0x91, 0x51, 0x93, 0x53, 0x52, 0x92,
        0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54,
        0x9c, 0x5c, 0x5d, 0x9d, 0x5f, 0x9f, 0x9e, 0x5e,
        0x5a, 0x9a, 0x9b, 0x5b, 0x99, 0x59, 0x58, 0x98,
        0x88, 0x48, 0x49, 0x89, 0x4b, 0x8b, 0x8a, 0x4a,
        0x4e, 0x8e, 0x8f, 0x4f, 0x8d, 0x4d, 0x4c, 0x8c,
        0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86,
        0x82, 0x42, 0x43, 0x83, 0x41, 0x81, 0x80, 0x40
};

int
onewire_crc(const void *buf, int len)
{
        const u_int8_t *p = buf;
        u_int8_t crc = 0;

        while (len--)
                crc = crc8_table[crc ^ *p++];

        return (crc);
}

u_int16_t
onewire_crc16(const void *buf, int len)
{
        const u_int8_t *p = buf;
        u_int16_t crc = 0;
        u_int16_t tmpcrc;
        int idx;

        while (len--) {
                idx = (crc & 0xff) ^ *p++;
                tmpcrc = crc16_table_high[idx] << 8;
                tmpcrc |= crc16_table_low[idx] ^ (crc >> 8);
                crc = tmpcrc;
        }

        return (crc);
}

const char *
onewire_famname(int type)
{
#ifdef ONEWIREVERBOSE
        const struct onewire_family *of;

        for (of = onewire_famtab; of->of_name != NULL; of++)
                if (of->of_type == type)
                        return (of->of_name);
#endif

        return (NULL);
}

int
onewire_matchbyfam(struct onewire_attach_args *oa,
    const struct onewire_matchfam *fams, int nent)
{
        const struct onewire_matchfam *om;
        int i;

        for (i = 0, om = fams; i < nent; i++, om++)
                if (ONEWIRE_ROM_FAMILY_TYPE(oa->oa_rom) == om->om_type)
                        return (1);

        return (0);
}