linux-imx/Documentation/sound/oss/ALS

ALS-007/ALS-100/ALS-200 based sound cards
=========================================

Support for sound cards based around the Avance Logic
ALS-007/ALS-100/ALS-200 chip is included.  These chips are a single
chip PnP sound solution which is mostly hardware compatible with the
Sound Blaster 16 card, with most differences occurring in the use of
the mixer registers.  For this reason the ALS code is integrated
as part of the Sound Blaster 16 driver (adding only 800 bytes to the
SB16 driver).

To use an ALS sound card under Linux, enable the following options as
modules in the sound configuration section of the kernel config:
  - 100% Sound Blaster compatibles (SB16/32/64, ESS, Jazz16) support
  - FM synthesizer (YM3812/OPL-3) support 
  - standalone MPU401 support may be required for some cards; for the
    ALS-007, when using isapnptools, it is required
Since the ALS-007/100/200 are PnP cards, ISAPnP support should probably be
compiled in.  If kernel level PnP support is not included, isapnptools will
be required to configure the card before the sound modules are loaded.

When using kernel level ISAPnP, the kernel should correctly identify and
configure all resources required by the card when the "sb" module is
inserted.  Note that the ALS-007 does not have a 16 bit DMA channel and that
the MPU401 interface on this card uses a different interrupt to the audio
section.  This should all be correctly configured by the kernel; if problems
with the MPU401 interface surface, try using the standalone MPU401 module,
passing "0" as the "sb" module's "mpu_io" module parameter to prevent the
soundblaster driver attempting to register the MPU401 itself.  The onboard
synth device can be accessed using the "opl3" module.

If isapnptools is used to wake up the sound card (as in 2.2.x), the settings
of the card's resources should be passed to the kernel modules ("sb", "opl3"
and "mpu401") using the module parameters.  When configuring an ALS-007, be
sure to specify different IRQs for the audio and MPU401 sections - this card
requires they be different.  For "sb", "io", "irq" and "dma" should be set
to the same values used to configure the audio section of the card with
isapnp.  "dma16" should be explicitly set to "-1" for an ALS-007 since this
card does not have a 16 bit dma channel; if not specified the kernel will
default to using channel 5 anyway which will cause audio not to work. 
"mpu_io" should be set to 0.  The "io" parameter of the "opl3" module should
also agree with the setting used by isapnp.  To get the MPU401 interface
working on an ALS-007 card, the "mpu401" module will be required since this
card uses separate IRQs for the audio and MPU401 sections and there is no
parameter available to pass a different IRQ to the "sb" driver (whose
inbuilt MPU401 driver would otherwise be fine).  Insert the mpu401 module
passing appropriate values using the "io" and "irq" parameters.

The resulting sound driver will provide the following capabilities:
  - 8 and 16 bit audio playback
  - 8 and 16 bit audio recording
  - Software selection of record source (line in, CD, FM, mic, master)
  - Record and playback of midi data via the external MPU-401
  - Playback of midi data using inbuilt FM synthesizer
  - Control of the ALS-007 mixer via any OSS-compatible mixer programs. 
    Controls available are Master (L&R), Line in (L&R), CD (L&R), 
    DSP/PCM/audio out (L&R), FM (L&R) and Mic in (mono).

Jonathan Woithe
jwoithe@just42.net
30 March 1998

Modified 2000-02-26 by Dave Forrest, drf5n@virginia.edu to add ALS100/ALS200
Modified 2000-04-10 by Paul Laufer, pelaufer@csupomona.edu to add ISAPnP info.
Modified 2000-11-19 by Jonathan Woithe, jwoithe@just42.net
 - updated information for kernel 2.4.x.