| 1 | /* $NetBSD: onewire_bitbang.c,v 1.1 2006/04/07 18:55:22 riz Exp $ */ |
| 2 | /* $OpenBSD: onewire_bitbang.c,v 1.1 2006/03/04 16:27:03 grange Exp $ */ |
| 3 | |
| 4 | /* |
| 5 | * Copyright (c) 2006 Alexander Yurchenko <grange@openbsd.org> |
| 6 | * |
| 7 | * Permission to use, copy, modify, and distribute this software for any |
| 8 | * purpose with or without fee is hereby granted, provided that the above |
| 9 | * copyright notice and this permission notice appear in all copies. |
| 10 | * |
| 11 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
| 12 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| 13 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
| 14 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| 15 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| 16 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
| 17 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| 18 | */ |
| 19 | |
| 20 | #include <sys/cdefs.h> |
| 21 | __KERNEL_RCSID(0, "$NetBSD: onewire_bitbang.c,v 1.1 2006/04/07 18:55:22 riz Exp $" ); |
| 22 | |
| 23 | /* |
| 24 | * 1-Wire bus bit-banging routines. |
| 25 | */ |
| 26 | |
| 27 | #include <sys/param.h> |
| 28 | #include <sys/systm.h> |
| 29 | #include <sys/device.h> |
| 30 | |
| 31 | #include <dev/onewire/onewirevar.h> |
| 32 | |
| 33 | int |
| 34 | onewire_bb_reset(const struct onewire_bbops *ops, void *arg) |
| 35 | { |
| 36 | int s, rv = 0, i; |
| 37 | |
| 38 | s = splhigh(); |
| 39 | ops->bb_tx(arg); |
| 40 | ops->bb_set(arg, 0); |
| 41 | DELAY(480); |
| 42 | ops->bb_set(arg, 1); |
| 43 | ops->bb_rx(arg); |
| 44 | DELAY(30); |
| 45 | for (i = 0; i < 6; i++) { |
| 46 | if ((rv = ops->bb_get(arg)) == 0) |
| 47 | break; |
| 48 | DELAY(20); |
| 49 | } |
| 50 | DELAY(450); |
| 51 | splx(s); |
| 52 | |
| 53 | return (rv); |
| 54 | } |
| 55 | |
| 56 | int |
| 57 | onewire_bb_bit(const struct onewire_bbops *ops, void *arg, int value) |
| 58 | { |
| 59 | int s, rv = 0, i; |
| 60 | |
| 61 | s = splhigh(); |
| 62 | ops->bb_tx(arg); |
| 63 | ops->bb_set(arg, 0); |
| 64 | DELAY(2); |
| 65 | if (value) { |
| 66 | ops->bb_set(arg, 1); |
| 67 | ops->bb_rx(arg); |
| 68 | for (i = 0; i < 15; i++) { |
| 69 | if ((rv = ops->bb_get(arg)) == 0) |
| 70 | break; |
| 71 | DELAY(2); |
| 72 | } |
| 73 | ops->bb_tx(arg); |
| 74 | } |
| 75 | DELAY(60); |
| 76 | ops->bb_set(arg, 1); |
| 77 | DELAY(5); |
| 78 | splx(s); |
| 79 | |
| 80 | return (rv); |
| 81 | } |
| 82 | |