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.\" 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 76and was imported into 77.Dx 2.1 . 78.Sh AUTHORS 79.An -nosplit 80The 81.Nm 82driver was written by 83.An Taku YAMAMOTO Aq Mt taku@cent.saitama-u.ac.jp . 84This manual page was written by 85.An Mark Santcroos Aq Mt marks@ripe.net . 86.Sh BUGS 87Some systems only perform output switching via SMM even though they export 88the proper information via ACPI. 89On such systems, the proper hotkeys or OEM driver (for example, 90.Xr acpi_toshiba 4 ) 91must be used instead. 92