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