74 lines
1.9 KiB
Groff
74 lines
1.9 KiB
Groff
.\" $NetBSD: gpioow.4,v 1.5 2014/03/18 18:20:39 riastradh Exp $
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.\" $OpenBSD: gpioow.4,v 1.3 2006/03/06 10:24:46 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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.Dd July 19, 2009
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.Dt GPIOOW 4
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.Os
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.Sh NAME
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.Nm gpioow
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.Nd 1-Wire bus bit-banging through GPIO pin
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.Sh SYNOPSIS
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.Cd "gpioow* at gpio? offset 0 mask 0x1"
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.Cd "gpioow* at gpio?"
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.Cd "onewire* at gpioow?"
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.Sh DESCRIPTION
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The
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.Nm
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driver allows bit-banging a 1-Wire bus as a master using one GPIO pin.
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The pin is used as a data signal.
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The GPIO pin must be able to drive an output and read an input.
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.Pp
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The pin number is specified in the kernel configuration with the
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.Ar offset
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locator.
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The
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.Ar mask
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locator should always be 0x1.
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The
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.Ar offset
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and
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.Ar mask
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can also be specified when
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.Nm
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is attached at runtime using the
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.Dv GPIOATTACH
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.Xr ioctl 2
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on the
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.Xr gpio 4
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device.
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.Sh SEE ALSO
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.Xr gpio 4 ,
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.Xr intro 4 ,
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.Xr onewire 4
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.Sh HISTORY
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The
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.Nm
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driver first appeared in
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.Ox 4.0
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and
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.Nx 4.0 .
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.Sh AUTHORS
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.An -nosplit
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The
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.Nm
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driver was written by
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.An Alexander Yurchenko Aq Mt grange@openbsd.org
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and was ported to
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.Nx
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by
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.An Jeff Rizzo Aq Mt riz@NetBSD.org .
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