70 lines
2.5 KiB
Groff
70 lines
2.5 KiB
Groff
.\" -*- nroff -*-
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.\"
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.\" Copyright (c) 1998 Doug Rabson
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.\"
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.\" All rights reserved.
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.\"
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.\" This program is free software.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
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.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
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.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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.\"
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.\" $FreeBSD$
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.\"
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.Dd January 21, 2015
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.Dt DEVICE_GET_SOFTC 9
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.Os
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.Sh NAME
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.Nm device_get_softc
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.Nd access driver private instance variables
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.Sh SYNOPSIS
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.In sys/param.h
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.In sys/bus.h
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.Ft void *
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.Fn device_get_softc "device_t dev"
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.Sh DESCRIPTION
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Return the driver-specific software context of
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.Fa dev .
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The softc is automatically allocated and zeroed when the device is
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attached.
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The softc is also initialized and present when a device is probed,
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but is subject to caveats as described in
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.Xr DEVICE_PROBE 9 .
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The size of the allocation is determined by the device's
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.Vt driver_t
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information used to define the driver.
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The softc typically encapsulates the state of this instance of the
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device.
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.Pp
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Driver writers are discouraged from using their own softc management
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mechanisms.
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Driver writers should not copy such mechanisms found in drivers in the
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tree that predate this function.
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.Sh RETURN VALUES
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The pointer to the driver-specific instance variable is returned.
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.Sh SEE ALSO
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.Xr device 9 ,
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.Xr DEVICE_PROBE 9 ,
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.Xr device_set_softc 9 ,
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.Xr driver 9
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.Sh AUTHORS
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This manual page was written by
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.An Doug Rabson .
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