.\" Copyright (c) 2005 Joel Dahl
.\" All rights reserved.
.\"
.\" 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 AUTHOR AND CONTRIBUTORS ``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 AUTHOR OR CONTRIBUTORS 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.
.\"
.Dd November 29, 2006
.Dt SND_VIA8233 4
.Os
.Sh NAME
.Nm snd_via8233
.Nd "VIA Technologies VT8233 bridge device driver"
.Sh SYNOPSIS
To compile this driver into the kernel, place the following lines in your
kernel configuration file:
.Bd -ragged -offset indent
.Cd "device sound"
.Cd "device snd_via8233"
.Ed
.Pp
Alternatively, to load the driver as a module at boot time, place the
following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
snd_via8233_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
bridge driver allows the generic audio driver,
.Xr sound 4 ,
to attach to the VIA VT8233 audio devices.
These audio chipsets are integrated in the southbridge on many VIA based
motherboards.
.Ss Runtime Configuration
The following
.Xr sysctl 8
variables are available in addition to those available to all
.Xr sound 4
devices:
.Bl -tag -width ".Va dev.pcm.%d.polling" -offset indent
.It Va dev.pcm.%d.polling
Experimental polling mode, where the driver operates by querying the device
state on each tick using
.Xr callout 9 .
Polling is disabled by default.
Do not enable it unless you are facing weird interrupt problems or if the
device cannot generate interrupts at all.
.El
.Sh HARDWARE
The
.Nm
driver supports the following audio chipsets:
.Pp
.Bl -bullet -compact
.It
VIA VT8233
.It
VIA VT8233A
.It
VIA VT8233C
.It
VIA VT8235
.It
VIA VT8237
.It
VIA VT8251
.El
.Sh SEE ALSO
.Xr sound 4
.Sh HISTORY
The
.Nm
device driver first appeared in
.Fx 4.7 .
.Sh AUTHORS
This manual page was written by
.An Joel Dahl Aq Mt joel@FreeBSD.org .
.Sh BUGS
The
.Nm
driver
does not support S/PDIF.
There is partial support in the code, so implementing it should be fairly
easy if the right hardware is available.