.\"	$OpenBSD: acpibtn.4,v 1.6 2021/09/03 12:11:15 kn Exp $
.\"
.\" Copyright (c) 2006 Michael Knudsen <mk@openbsd.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd $Mdocdate: September 3 2021 $
.Dt ACPIBTN 4
.Os
.Sh NAME
.Nm acpibtn
.Nd ACPI button
.Sh SYNOPSIS
.Cd "acpibtn* at acpi?"
.Sh DESCRIPTION
The
.Nm
driver handles events triggered by ACPI buttons.
Currently, only power button, sleep button and lid status events are supported.
.Pp
The power button event is handled according to the
.Va machdep.pwraction
.Xr sysctl 8 .
Valid values are:
.Pp
.Bl -tag -width 3n -offset indent -compact
.It 0
Do nothing.
.It 1
Perform a regular system shutdown and power off the machine if the
.Va hw.allowpowerdown
sysctl is set to 1.
.It 2
Put the system into suspend (deep sleep) state.
.El
.Pp
The sleep button event puts the system into suspend (deep sleep) state.
.Pp
The lid status event is handled according to the
.Va machdep.lidaction
sysctl.
Valid values are:
.Pp
.Bl -tag -width 3n -offset indent -compact
.It 0
Do nothing.
.It 1
Put the system into suspend (deep sleep) state.
.It 2
Put the system into hibernation.
System memory is saved to disk (swap space)
and the machine is powered down.
For machines supporting the
.Xr acpi 4
style hibernate functionality, on resume a full kernel
boot will occur, followed by the reading of the saved
memory image.
The image will then be unpacked and the system resumed
at the point immediately after the hibernation request.
.El
.Pp
The lid status is set up as a sensor and can be monitored using
.Xr sysctl 8
or
.Xr sensorsd 8 .
.Sh SEE ALSO
.Xr acpi 4 ,
.Xr intro 4 ,
.Xr sensorsd 8 ,
.Xr sysctl 8
.Sh HISTORY
The
.Nm
driver first appeared in
.Ox 3.9 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Marco Peereboom Aq Mt marco@openbsd.org .