93 lines
2.7 KiB
Groff
93 lines
2.7 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 June 16, 1998
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.Dt DEVICE_GET_STATE 9
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.Os
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.Sh NAME
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.Nm device_get_state ,
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.Nm device_busy ,
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.Nm device_unbusy ,
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.Nm device_is_alive
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.Nd manipulate device state
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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 device_state_t
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.Fn device_get_state "device_t dev"
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.Ft void
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.Fn device_busy "device_t dev"
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.Ft void
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.Fn device_unbusy "device_t dev"
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.Ft int
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.Fn device_is_alive "device_t dev"
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.Sh DESCRIPTION
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The current state of a device is accessed by calling
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.Fn device_get_state
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which returns
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.Dv DS_NOTPRESENT ,
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.Dv DS_ALIVE ,
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.Dv DS_ATTACHED
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or
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.Dv DS_BUSY
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(described in
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.Xr device 9 ) .
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To test see if a device was successfully probed, call
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.Fn device_is_alive
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which simply returns if the state is greater or equal to
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.Dv DS_ALIVE .
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.Pp
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Each device has a busy count which is incremented when
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.Fn device_busy
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is called and decremented when
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.Fn device_unbusy
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is called. Both routines return an error if the device state is less
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than
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.Dv DS_ATTACHED .
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.Pp
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When
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.Fn device_busy
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is called on a device in the
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.Dv DS_ATTACHED
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state, the device changes to the
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.Dv DS_BUSY
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state.
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When
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.Fn device_unbusy
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is called and after decrementing, the busy count for the device is
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zero, the device changes to the
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.Dv DS_ATTACHED
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state.
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.Sh SEE ALSO
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.Xr device 9
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.Sh AUTHORS
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This man page was written by
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.An Doug Rabson .
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