Return to onewire_bitbang.c CVS log

Up to [local] / sys / dev / onewire

Annotation of sys/dev/onewire/onewire_bitbang.c, Revision 1.1.1.1

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: }