82 lines
1.9 KiB
C
82 lines
1.9 KiB
C
/* $NetBSD: onewire_bitbang.c,v 1.1 2006/04/07 18:55:22 riz Exp $ */
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/* $OpenBSD: onewire_bitbang.c,v 1.1 2006/03/04 16:27:03 grange Exp $ */
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/*
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* Copyright (c) 2006 Alexander Yurchenko <grange@openbsd.org>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: onewire_bitbang.c,v 1.1 2006/04/07 18:55:22 riz Exp $");
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/*
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* 1-Wire bus bit-banging routines.
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/device.h>
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#include <dev/onewire/onewirevar.h>
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int
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onewire_bb_reset(const struct onewire_bbops *ops, void *arg)
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{
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int s, rv = 0, i;
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s = splhigh();
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ops->bb_tx(arg);
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ops->bb_set(arg, 0);
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DELAY(480);
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ops->bb_set(arg, 1);
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ops->bb_rx(arg);
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DELAY(30);
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for (i = 0; i < 6; i++) {
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if ((rv = ops->bb_get(arg)) == 0)
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break;
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DELAY(20);
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}
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DELAY(450);
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splx(s);
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return (rv);
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}
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int
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onewire_bb_bit(const struct onewire_bbops *ops, void *arg, int value)
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{
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int s, rv = 0, i;
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s = splhigh();
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ops->bb_tx(arg);
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ops->bb_set(arg, 0);
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DELAY(2);
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if (value) {
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ops->bb_set(arg, 1);
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ops->bb_rx(arg);
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for (i = 0; i < 15; i++) {
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if ((rv = ops->bb_get(arg)) == 0)
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break;
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DELAY(2);
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}
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ops->bb_tx(arg);
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}
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DELAY(60);
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ops->bb_set(arg, 1);
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DELAY(5);
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splx(s);
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return (rv);
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}
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