122 lines
3.8 KiB
Groff
122 lines
3.8 KiB
Groff
.\" -*- nroff -*-
|
|
.\"
|
|
.\" Copyright (c) 1998 Doug Rabson
|
|
.\"
|
|
.\" 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 April 30, 2020
|
|
.Dt DRIVER 9
|
|
.Os
|
|
.Sh NAME
|
|
.Nm driver
|
|
.Nd structure describing a device driver
|
|
.Sh SYNOPSIS
|
|
.Bd -literal
|
|
#include <sys/param.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/bus.h>
|
|
#include <sys/module.h>
|
|
|
|
static int foo_probe(device_t);
|
|
static int foo_attach(device_t);
|
|
static int foo_detach(device_t);
|
|
static int foo_frob(device_t, int, int);
|
|
static int foo_twiddle(device_t, char *);
|
|
|
|
static device_method_t foo_methods[] = {
|
|
/* Methods from the device interface */
|
|
DEVMETHOD(device_probe, foo_probe),
|
|
DEVMETHOD(device_attach, foo_attach),
|
|
DEVMETHOD(device_detach, foo_detach),
|
|
|
|
/* Methods from the bogo interface */
|
|
DEVMETHOD(bogo_frob, foo_frob),
|
|
DEVMETHOD(bogo_twiddle, foo_twiddle),
|
|
|
|
/* Terminate method list */
|
|
DEVMETHOD_END
|
|
};
|
|
|
|
static driver_t foo_driver = {
|
|
"foo",
|
|
foo_methods,
|
|
sizeof(struct foo_softc)
|
|
};
|
|
|
|
static devclass_t foo_devclass;
|
|
|
|
DRIVER_MODULE(foo, bogo, foo_driver, foo_devclass, NULL, NULL);
|
|
.Ed
|
|
.Sh DESCRIPTION
|
|
Each driver in the kernel is described by a
|
|
.Dv driver_t
|
|
structure.
|
|
The structure contains the name of the device, a pointer
|
|
to a list of methods, an indication of the kind of device which the
|
|
driver implements and the size of the private data which the driver
|
|
needs to associate with a device instance.
|
|
Each driver will implement
|
|
one or more sets of methods (called interfaces).
|
|
The example driver
|
|
implements the standard "driver" interface and the fictitious "bogo"
|
|
interface.
|
|
.Pp
|
|
When a driver is registered with the system (by the
|
|
.Dv DRIVER_MODULE
|
|
macro, see
|
|
.Xr DRIVER_MODULE 9 ) ,
|
|
it is added to the list of drivers contained in the devclass
|
|
of its parent bus type.
|
|
For instance all PCI drivers would be
|
|
contained in the devclass named "pci" and all ISA drivers would be
|
|
in the devclass named "isa".
|
|
The reason the drivers are not held in the device object of the parent
|
|
bus is to handle multiple instances of a given type of bus.
|
|
The
|
|
.Dv DRIVER_MODULE
|
|
macro will also create the devclass with the name of the driver and
|
|
can optionally call extra initialisation code in the driver by
|
|
specifying an extra module event handler and argument as the last two
|
|
arguments.
|
|
.Sh SEE ALSO
|
|
.Xr devclass 9 ,
|
|
.Xr device 9 ,
|
|
.Xr DEVICE_ATTACH 9 ,
|
|
.Xr DEVICE_DETACH 9 ,
|
|
.Xr DEVICE_IDENTIFY 9 ,
|
|
.Xr DEVICE_PROBE 9 ,
|
|
.Xr DEVICE_SHUTDOWN 9 ,
|
|
.Xr DRIVER_MODULE 9
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
framework first appeared in
|
|
.Fx 2.2.7 .
|
|
.Sh AUTHORS
|
|
This manual page was written by
|
|
.An Doug Rabson .
|