forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
186 lines
5.9 KiB
186 lines
5.9 KiB
================================= |
|
Notes on Maya44 USB Audio Support |
|
================================= |
|
|
|
.. note:: |
|
The following is the original document of Rainer's patch that the |
|
current maya44 code based on. Some contents might be obsoleted, but I |
|
keep here as reference -- tiwai |
|
|
|
Feb 14, 2008 |
|
|
|
Rainer Zimmermann <[email protected]> |
|
|
|
STATE OF DEVELOPMENT |
|
==================== |
|
|
|
This driver is being developed on the initiative of Piotr Makowski ([email protected]) and financed by Lars Bergmann. |
|
Development is carried out by Rainer Zimmermann ([email protected]). |
|
|
|
ESI provided a sample Maya44 card for the development work. |
|
|
|
However, unfortunately it has turned out difficult to get detailed programming information, so I (Rainer Zimmermann) had to find out some card-specific information by experiment and conjecture. Some information (in particular, several GPIO bits) is still missing. |
|
|
|
This is the first testing version of the Maya44 driver released to the alsa-devel mailing list (Feb 5, 2008). |
|
|
|
|
|
The following functions work, as tested by Rainer Zimmermann and Piotr Makowski: |
|
|
|
- playback and capture at all sampling rates |
|
- input/output level |
|
- crossmixing |
|
- line/mic switch |
|
- phantom power switch |
|
- analogue monitor a.k.a bypass |
|
|
|
|
|
The following functions *should* work, but are not fully tested: |
|
|
|
- Channel 3+4 analogue - S/PDIF input switching |
|
- S/PDIF output |
|
- all inputs/outputs on the M/IO/DIO extension card |
|
- internal/external clock selection |
|
|
|
|
|
*In particular, we would appreciate testing of these functions by anyone who has access to an M/IO/DIO extension card.* |
|
|
|
|
|
Things that do not seem to work: |
|
|
|
- The level meters ("multi track") in 'alsamixer' do not seem to react to signals in (if this is a bug, it would probably be in the existing ICE1724 code). |
|
|
|
- Ardour 2.1 seems to work only via JACK, not using ALSA directly or via OSS. This still needs to be tracked down. |
|
|
|
|
|
DRIVER DETAILS |
|
============== |
|
|
|
the following files were added: |
|
|
|
* pci/ice1724/maya44.c - Maya44 specific code |
|
* pci/ice1724/maya44.h |
|
* pci/ice1724/ice1724.patch |
|
* pci/ice1724/ice1724.h.patch - PROPOSED patch to ice1724.h (see SAMPLING RATES) |
|
* i2c/other/wm8776.c - low-level access routines for Wolfson WM8776 codecs |
|
* include/wm8776.h |
|
|
|
|
|
Note that the wm8776.c code is meant to be card-independent and does not actually register the codec with the ALSA infrastructure. |
|
This is done in maya44.c, mainly because some of the WM8776 controls are used in Maya44-specific ways, and should be named appropriately. |
|
|
|
|
|
the following files were created in pci/ice1724, simply #including the corresponding file from the alsa-kernel tree: |
|
|
|
* wtm.h |
|
* vt1720_mobo.h |
|
* revo.h |
|
* prodigy192.h |
|
* pontis.h |
|
* phase.h |
|
* maya44.h |
|
* juli.h |
|
* aureon.h |
|
* amp.h |
|
* envy24ht.h |
|
* se.h |
|
* prodigy_hifi.h |
|
|
|
|
|
*I hope this is the correct way to do things.* |
|
|
|
|
|
SAMPLING RATES |
|
============== |
|
|
|
The Maya44 card (or more exactly, the Wolfson WM8776 codecs) allow a maximum sampling rate of 192 kHz for playback and 92 kHz for capture. |
|
|
|
As the ICE1724 chip only allows one global sampling rate, this is handled as follows: |
|
|
|
* setting the sampling rate on any open PCM device on the maya44 card will always set the *global* sampling rate for all playback and capture channels. |
|
|
|
* In the current state of the driver, setting rates of up to 192 kHz is permitted even for capture devices. |
|
|
|
*AVOID CAPTURING AT RATES ABOVE 96kHz*, even though it may appear to work. The codec cannot actually capture at such rates, meaning poor quality. |
|
|
|
|
|
I propose some additional code for limiting the sampling rate when setting on a capture pcm device. However because of the global sampling rate, this logic would be somewhat problematic. |
|
|
|
The proposed code (currently deactivated) is in ice1712.h.patch, ice1724.c and maya44.c (in pci/ice1712). |
|
|
|
|
|
SOUND DEVICES |
|
============= |
|
|
|
PCM devices correspond to inputs/outputs as follows (assuming Maya44 is card #0): |
|
|
|
* hw:0,0 input - stereo, analog input 1+2 |
|
* hw:0,0 output - stereo, analog output 1+2 |
|
* hw:0,1 input - stereo, analog input 3+4 OR S/PDIF input |
|
* hw:0,1 output - stereo, analog output 3+4 (and SPDIF out) |
|
|
|
|
|
NAMING OF MIXER CONTROLS |
|
======================== |
|
|
|
(for more information about the signal flow, please refer to the block diagram on p.24 of the ESI Maya44 manual, or in the ESI windows software). |
|
|
|
|
|
PCM |
|
(digital) output level for channel 1+2 |
|
PCM 1 |
|
same for channel 3+4 |
|
|
|
Mic Phantom+48V |
|
switch for +48V phantom power for electrostatic microphones on input 1/2. |
|
|
|
Make sure this is not turned on while any other source is connected to input 1/2. |
|
It might damage the source and/or the maya44 card. |
|
|
|
Mic/Line input |
|
if switch is on, input jack 1/2 is microphone input (mono), otherwise line input (stereo). |
|
|
|
Bypass |
|
analogue bypass from ADC input to output for channel 1+2. Same as "Monitor" in the windows driver. |
|
Bypass 1 |
|
same for channel 3+4. |
|
|
|
Crossmix |
|
cross-mixer from channels 1+2 to channels 3+4 |
|
Crossmix 1 |
|
cross-mixer from channels 3+4 to channels 1+2 |
|
|
|
IEC958 Output |
|
switch for S/PDIF output. |
|
|
|
This is not supported by the ESI windows driver. |
|
S/PDIF should output the same signal as channel 3+4. [untested!] |
|
|
|
|
|
Digitial output selectors |
|
These switches allow a direct digital routing from the ADCs to the DACs. |
|
Each switch determines where the digital input data to one of the DACs comes from. |
|
They are not supported by the ESI windows driver. |
|
For normal operation, they should all be set to "PCM out". |
|
|
|
H/W |
|
Output source channel 1 |
|
H/W 1 |
|
Output source channel 2 |
|
H/W 2 |
|
Output source channel 3 |
|
H/W 3 |
|
Output source channel 4 |
|
|
|
H/W 4 ... H/W 9 |
|
unknown function, left in to enable testing. |
|
|
|
Possibly some of these control S/PDIF output(s). |
|
If these turn out to be unused, they will go away in later driver versions. |
|
|
|
Selectable values for each of the digital output selectors are: |
|
|
|
PCM out |
|
DAC output of the corresponding channel (default setting) |
|
Input 1 ... Input 4 |
|
direct routing from ADC output of the selected input channel |
|
|
|
|