snd_maestro3(4)

NAME

snd_maestro3 - ESS Maestro3/Allegro-1 bridge device driver

SYNOPSIS

To compile this driver into the kernel, place the  following
lines in your
kernel configuration file:
      device sound
      device snd_maestro3
Alternatively,  to load the driver as a module at boot time,
place the
following line in loader.conf(5):
      snd_maestro3_load="YES"

DESCRIPTION

The snd_maestro3 driver provides support for the ESS Mae

stro3 and Allegro-1 sound chips under the PCM framework. These chips are

mostly found
in laptop computers and feature an AC97 mixer, a multi-chan

nel sample
rate converter that can mix up to four digital audio streams

in hardware,
recording support, and external volume control buttons.

The firmware for the sound processor is licensed under the

GNU Public
License, and thus this driver is not included in the default

GENERIC kernel.

HARDWARE

The snd_maestro3 driver supports the following audio de

vices:

+o ESS Technology Allegro-1
+o ESS Technology Maestro3

DIAGNOSTICS

The hardware volume control buttons can be connected to two

different pin
sets (GPIO or GD) on the chip, depending on the manufactur

er. The driver
has no way of determining this configuration, so a hint may

be used to
override the default guess. The default setting for hard

ware volume control assumes that GD pins are wired to control the hardware

volume. For
systems that have the GPIO pins wired to the hardware volume

control buttons, add the line ``hint.pcm.0.hwvol_config="0"'' to the

file
/boot/device.hints to override the default setting.

SEE ALSO

sound(4), loader.conf(5)

HISTORY

The snd_maestro3 driver first appeared in FreeBSD 4.3.

AUTHORS

Scott Long <scottl@FreeBSD.org>
Darrel Anderson <anderson@cs.duke.edu>

BSD December 15, 2005

BSD