.\" Copyright (c) 2001 Alexander Langer
.\"
.\" 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: src/share/man/man9/DEV_MODULE.9,v 1.1.2.3 2001/12/17 11:30:18 ru Exp $
.\"
.Dd February 10, 2009
.Dt DEV_MODULE 9
.Os
.Sh NAME
.Nm DEV_MODULE
.Nd device driver module declaration macro
.Sh SYNOPSIS
.In sys/module.h
.In sys/conf.h
.Fn DEV_MODULE "name" "modeventhand_t evh" "void *arg"
.Sh DESCRIPTION
The
.Fn DEV_MODULE
macro declares a device driver kernel module.
It fills in a
.Vt moduledata_t
structure and then calls
.Fn DECLARE_MODULE
with the correct args, where
.Fa name
is the name of the module and
.Fa evh
(with its argument
.Fa arg )
is the event handler for the module (refer to
.Xr DECLARE_MODULE 9
for more information).
The event handler is supposed to create the device with
.Fn make_dev
on load and to destroy it when it is unloaded using
.Fn destroy_dev .
.Sh EXAMPLES
.Bd -literal
#include <sys/module.h>
#include <sys/conf.h>

static struct dev_ops foo_ops = { ... };

static cdev_t sdev;

static int
foo_load(module_t mod, int cmd, void *arg)
{
    int err = 0;

    dev_ops_add(&foo_ops, ...);

    switch (cmd) {
    case MOD_LOAD:
        sdev = make_dev(&foo_ops, 0, UID_ROOT, GID_WHEEL, 0600, "foo");

        /* We must obtain a reference to sdev, so we can destroy it later */
        reference_dev(sdev);
        break;          /* Success*/

    case MOD_UNLOAD:
    case MOD_SHUTDOWN:
        destroy_dev(sdev);

        /* The same mask and match must be specified, as in dev_ops_add() */
        dev_ops_remove(&foo_ops, ...);
        break;          /* Success*/

    default:
        err = EINVAL;
        break;
    }

    return(err);
}

DEV_MODULE(foo, foo_load, NULL);
.Ed
.Sh SEE ALSO
.Xr DECLARE_MODULE 9 ,
.Xr destroy_dev 9 ,
.Xr make_dev 9 ,
.Xr module 9
.Sh AUTHORS
This manual page was written by
.An Alexander Langer Aq Mt alex@FreeBSD.org .