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: src/share/man/man4/acpi_video.4,v 1.4 2005/07/15 17:35:25 hrs Exp $ 27.\" $DragonFly: src/share/man/man4/acpi_video.4,v 1.1 2008/08/28 09:47:04 hasso Exp $ 28.\" 29.Dd November 8, 2004 30.Dt ACPI_VIDEO 4 31.Os 32.Sh NAME 33.Nm acpi_video 34.Nd ACPI Video Extensions driver 35.Sh SYNOPSIS 36.Cd "device acpi_video" 37.Sh DESCRIPTION 38This driver uses the ACPI Video Extensions to control display switching and 39backlight brightness. 40The availability of the 41.Xr sysctl 8 42variables depends on the functions offered by the host's ACPI implementation. 43.Sh SYSCTL VARIABLES 44The following sysctls are currently implemented, 45where 46.Aq Ar device 47is 48.Va crt , lcd , 49or 50.Va tv : 51.Bl -tag -width indent 52.It Va hw.acpi.video. Ns Ao Ar device Ac Ns Va .active 53Current state of the output device. 54.It Va hw.acpi.video. Ns Ao Ar device Ac Ns Va .levels 55List of supported brightness levels. 56.It Va hw.acpi.video. Ns Ao Ar device Ac Ns Va .brightness 57Current brightness level of the device. 58.It Va hw.acpi.video. Ns Ao Ar device Ac Ns Va .fullpower 59Preset brightness level to be used in full power mode. 60.It Va hw.acpi.video. Ns Ao Ar device Ac Ns Va .economy 61Preset brightness level to be used in economy mode. 62.El 63.Pp 64Defaults for these variables can be set in 65.Xr sysctl.conf 5 , 66which is parsed at boot-time. 67.Sh SEE ALSO 68.Xr acpi 4 , 69.Xr loader.conf 5 , 70.Xr sysctl.conf 5 , 71.Xr sysctl 8 72.Sh HISTORY 73The 74.Nm 75driver first appeared in 76.Fx 5.3 77and was imported into 78.Dx 2.1 . 79.Sh AUTHORS 80.An -nosplit 81The 82.Nm 83driver was written by 84.An Taku YAMAMOTO Aq taku@cent.saitama-u.ac.jp . 85This manual page was written by 86.An Mark Santcroos Aq marks@ripe.net . 87.Sh BUGS 88Some systems only perform output switching via SMM even though they export 89the proper information via ACPI. 90On such systems, the proper hotkeys or OEM driver (for example, 91.Xr acpi_toshiba 4 ) 92must be used instead. 93