.\" -*- nroff -*-
.\"
.\" Copyright (c) 2004 M. Warner Losh <imp@FreeBSD.org>
.\"
.\" 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.
.\"
.Dd April 8, 2018
.Dt BUS_ADD_CHILD 9
.Os
.Sh NAME
.Nm BUS_ADD_CHILD
.Nd "add a device node to the tree with a given priority"
.Sh SYNOPSIS
.In sys/param.h
.In sys/bus.h
.Ft device_t
.Fn BUS_ADD_CHILD "device_t dev" "int order" "const char *name" "int unit"
.Sh DESCRIPTION
The
.Fn BUS_ADD_CHILD
method
is used by the driver identify routine to add devices to the tree.
It can also be used to add children to buses that implement this
routine in other contexts, although the behavior is bus specific.
Please see
.Xr device_add_child 9
for more details.
The interface is the same as
.Xr device_add_child 9
however, the bus'
.Fn BUS_ADD_CHILD
is called.
.Pp
Buses implementing
.Fn BUS_ADD_CHILD
should insert the device into the tree using
.Xr device_add_child 9
before adding things such as their own ivars and resource lists to the device.
.Fn BUS_ADD_CHILD
is not called by
.Xr device_add_child 9 .
.Fn BUS_ADD_CHILD
instead calls
.Xr device_add_child 9 .
.Pp
A panic will result when called for a bus that does not implement
.Fn BUS_ADD_CHILD .
Some buses require a special bus-specific routine to be called instead
of
.Fn BUS_ADD_CHILD .
.Sh RETURN VALUES
The
.Fn BUS_ADD_CHILD
method returns
.Vt device_t
added to the tree, or
.Dv NULL
to indicate failure.
.Sh SEE ALSO
.Xr device 9 ,
.Xr device_add_child 9 ,
.Xr driver 9
.Sh AUTHORS
This manual page was written by
.An M. Warner Losh .