xref: /freebsd/share/man/man4/acpi_video.4 (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
1.\"
2.\" Copyright (c) 2004 Mark Santcroos <marks@ripe.net>
3.\" All rights reserved.
4.\"
5.\" Redistribution and use in source and binary forms, with or without
6.\" modification, are permitted provided that the following conditions
7.\" are met:
8.\" 1. Redistributions of source code must retain the above copyright
9.\"    notice, this list of conditions and the following disclaimer.
10.\" 2. Redistributions in binary form must reproduce the above copyright
11.\"    notice, this list of conditions and the following disclaimer in the
12.\"    documentation and/or other materials provided with the distribution.
13.\"
14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24.\" SUCH DAMAGE.
25.\"
26.\" $FreeBSD$
27.\"
28.Dd November 8, 2004
29.Dt ACPI_VIDEO 4
30.Os
31.Sh NAME
32.Nm acpi_video
33.Nd ACPI Video Extensions driver
34.Sh SYNOPSIS
35.Cd "device acpi_video"
36.Sh DESCRIPTION
37This driver uses the ACPI Video Extensions to control display switching and
38backlight brightness.
39The availability of the
40.Xr sysctl 8
41variables depends on the functions offered by the host's ACPI implementation.
42.Sh SYSCTL VARIABLES
43The following sysctls are currently implemented,
44where
45.Aq Ar device
46is
47.Va crt , lcd ,
48or
49.Va tv :
50.Bl -tag -width indent
51.It Va hw.acpi.video. Ns Ao Ar device Ac Ns Va .active
52Current state of the output device.
53.It Va hw.acpi.video. Ns Ao Ar device Ac Ns Va .levels
54List of supported brightness levels.
55.It Va hw.acpi.video. Ns Ao Ar device Ac Ns Va .brightness
56Current brightness level of the device.
57.It Va hw.acpi.video. Ns Ao Ar device Ac Ns Va .fullpower
58Preset brightness level to be used in full power mode.
59.It Va hw.acpi.video. Ns Ao Ar device Ac Ns Va .economy
60Preset brightness level to be used in economy mode.
61.El
62.Pp
63Defaults for these variables can be set in
64.Xr sysctl.conf 5 ,
65which is parsed at boot-time.
66.Sh SEE ALSO
67.Xr acpi 4 ,
68.Xr loader.conf 5 ,
69.Xr sysctl.conf 5 ,
70.Xr sysctl 8
71.Sh HISTORY
72The
73.Nm
74driver first appeared in
75.Fx 5.3 .
76.Sh AUTHORS
77.An -nosplit
78The
79.Nm
80driver was written by
81.An Taku YAMAMOTO Aq Mt taku@cent.saitama-u.ac.jp .
82This manual page was written by
83.An Mark Santcroos Aq Mt marks@ripe.net .
84.Sh BUGS
85Some systems only perform output switching via SMM even though they export
86the proper information via ACPI.
87On such systems, the proper hotkeys or OEM driver (for example,
88.Xr acpi_toshiba 4 )
89must be used instead.
90