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Annotation of sys/dev/onewire/onewire_bitbang.c, Revision 1.1

1.1     ! nbrk        1: /*     $OpenBSD: onewire_bitbang.c,v 1.1 2006/03/04 16:27:03 grange 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 bit-banging routines.
        !            21:  */
        !            22:
        !            23: #include <sys/param.h>
        !            24: #include <sys/systm.h>
        !            25: #include <sys/device.h>
        !            26:
        !            27: #include <dev/onewire/onewirevar.h>
        !            28:
        !            29: int
        !            30: onewire_bb_reset(const struct onewire_bbops *ops, void *arg)
        !            31: {
        !            32:        int s, rv, i;
        !            33:
        !            34:        s = splhigh();
        !            35:        ops->bb_tx(arg);
        !            36:        ops->bb_set(arg, 0);
        !            37:        DELAY(480);
        !            38:        ops->bb_set(arg, 1);
        !            39:        ops->bb_rx(arg);
        !            40:        DELAY(30);
        !            41:        for (i = 0; i < 6; i++) {
        !            42:                if ((rv = ops->bb_get(arg)) == 0)
        !            43:                        break;
        !            44:                DELAY(20);
        !            45:        }
        !            46:        DELAY(450);
        !            47:        splx(s);
        !            48:
        !            49:        return (rv);
        !            50: }
        !            51:
        !            52: int
        !            53: onewire_bb_bit(const struct onewire_bbops *ops, void *arg, int value)
        !            54: {
        !            55:        int s, rv, i;
        !            56:
        !            57:        s = splhigh();
        !            58:        ops->bb_tx(arg);
        !            59:        ops->bb_set(arg, 0);
        !            60:        DELAY(2);
        !            61:        if (value) {
        !            62:                ops->bb_set(arg, 1);
        !            63:                ops->bb_rx(arg);
        !            64:                for (i = 0; i < 15; i++) {
        !            65:                        if ((rv = ops->bb_get(arg)) == 0)
        !            66:                                break;
        !            67:                        DELAY(2);
        !            68:                }
        !            69:                ops->bb_tx(arg);
        !            70:        }
        !            71:        DELAY(60);
        !            72:        ops->bb_set(arg, 1);
        !            73:        DELAY(5);
        !            74:        splx(s);
        !            75:
        !            76:        return (rv);
        !            77: }