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 Maestro3 and
Allegro-1 sound chips under the PCM framework. These chips are mostly
found in laptop computers and feature an AC97 mixer, a multi-channel
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 devices:
· ESS Technology Allegro-1
· 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 manufacturer. The driver
has no way of determining this configuration, so a hint may be used to
override the default guess. The default setting for hardware 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〉