.\" Copyright (c) 2006 Joel Dahl <joel@FreeBSD.org>
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.Dd October 1, 2006
.Dt SND_HDA 4
.Os
.Sh NAME
.Nm snd_hda
.Nd "Intel High Definition Audio 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_hda"
.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_hda_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
bridge device driver allows the generic audio driver,
.Xr sound 4 ,
to attach to Intel High Definition Audio devices.
The
.Nm
driver supports hardware that conforms with revision 1.0 of the Intel High
Definition Audio specification and tries to behave much like the Microsoft
Universal Audio Architecture (UAA) draft (revision 0.7b) for handling audio
devices.
HDA acts like a primary bus, similar to
.Xr miibus 4 ,
for handling various child buses such as audio, modem and HDMI (High Definition
Multimedia Interface).
Only audio is implemented in the
.Nm
driver.
.Pp
The High Definition (HD) Audio specification was developed by Intel as the
logical successor of the old AC'97 specification and has several advantages,
such as higher bandwidth which allows more channels and more detailed formats,
support for several logical audio devices, and general purpose DMA channels.
.Pp
The HDA specification defines the register-level interface, physical link
characteristics, codec programming models, and codec architectural components.
This specification is intended for both device driver developers and hardware
component designers.
.Sh HARDWARE
The
.Nm
driver supports the following audio chipsets:
.Pp
.Bl -bullet -compact
.It
ATI SB450
.It
Intel 82801F
.It
Intel 82801G
.It
nVidia MCP51
.It
nVidia MCP55
.El
.Pp
Generic Audio chipsets compatible with the Intel HDA specification should work,
but have not been verified yet.
The following codecs have been verified to work:
.Pp
.Bl -bullet -compact
.It
Analog Device AD1981HD
.It
Analog Device AD1983
.It
Analog Device AD1986A
.It
CMedia CMI9880
.It
Conexant Venice
.It
Realtek ALC260
.It
Realtek ALC861
.It
Realtek ALC880
.It
Realtek ALC882
.It
Sigmatel STAC9220
.It
Sigmatel STAC9221
.It
Sigmatel STAC9221D
.It
Sigmatel STAC922XD
.El
.Sh SEE ALSO
.Xr sound 4 ,
.Xr loader.conf 5
.Sh HISTORY
The
.Nm
device driver first appeared in
.Fx 7.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Stephane E. Potvin Aq sepotvin@videotron.ca
and
.An Ariff Abdullah Aq ariff@FreeBSD.org .
This manual page was written by
.An Joel Dahl Aq joel@FreeBSD.org .
.Sh BUGS
There are a couple of missing features, such as support for Digital
S/PDIF and multichannel output.
.Pp
A few Hardware/OEM vendors tend to screw up BIOS settings, thus
rendering the
.Nm
driver useless, which usually results in a state where the
.Nm
driver seems to attach and work, but without any sound.