diff options
author | imp <imp@FreeBSD.org> | 2003-03-28 07:09:17 +0000 |
---|---|---|
committer | imp <imp@FreeBSD.org> | 2003-03-28 07:09:17 +0000 |
commit | 256832481a5d5613f162af09adac9ebc61cc5930 (patch) | |
tree | db2bb668f36589c57804476319e4abfe8a469ba1 /share/man/man9/bus_child_present.9 | |
parent | ad18bcce01bfbacc411cf806953efa12e3c519b5 (diff) | |
download | FreeBSD-src-256832481a5d5613f162af09adac9ebc61cc5930.zip FreeBSD-src-256832481a5d5613f162af09adac9ebc61cc5930.tar.gz |
Create a man page for bus_child_present(9), a function to see if a
given device is considered accessible by its parent device bus driver
(or its parent, etc).
Diffstat (limited to 'share/man/man9/bus_child_present.9')
-rw-r--r-- | share/man/man9/bus_child_present.9 | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/share/man/man9/bus_child_present.9 b/share/man/man9/bus_child_present.9 new file mode 100644 index 0000000..995a482 --- /dev/null +++ b/share/man/man9/bus_child_present.9 @@ -0,0 +1,82 @@ +.\" -*- nroff -*- +.\" +.\" Copyright (c) 2003 M. Warner Losh +.\" +.\" All rights reserved. +.\" +.\" This program is free software. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR +.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES +.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. +.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, +.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT +.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF +.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.Dd March 27, 2003 +.Dt BUS_CHILD_PRESENT 9 +.Os +.Sh NAME +.Nm bus_child_present +.Nd Ask the bus driver to see if this device is still really present. +.Sh SYNOPSIS +.In sys/param.h +.In sys/bus.h +.Pp +.In machine/bus.h +.In sys/rman.h +.In machine/resource.h +.Ft int +.Fn bus_child_present "device_t dev" +.Sh DESCRIPTION +Requests that the parent device driver of +.Fa dev +check to see if the +hardware represented by +.Fa dev +is still physically accessible at this time. +While the notion of accessible varies from bus to bus, generally +hardware that is not acceessible cannot be accessed via the bus_space +methods that would otherwise be used to acceess the device. +.Pp +This does not ask the question 'does this device have children?' which +can better be answered by +.Xr device_get_children 9 . +.Sh RETURN VALUES +A zero return value indicates that the device is not present in the +system. +A non-zero return value indicates that the device is present in the +system, or that the state of the device cannot be determined. +.Sh EXAMPLES +This is some example code. +It only calls stop when the dc device is actually present. +.Bd -literal + device_t dev; + dc_softc *sc; + + sc = device_get_softc(dev); + if (bus_child_present(dev)) + dc_stop(sc); +.Ed +.Sh SEE ALSO +.Xr device 9 , +.Xr driver 9 +.Sh AUTHORS +.An -nosplit +This man page was written by +.An Warner Losh Aq imp@FreeBSD.org . |