Realtek I2C codec datasheet

[Paul Mansfield]

The way I think sound works is this...

looking at this diagram:
http://cdn.arstechnica.net/wp-content/uploads/2013/09/Screen-Shot-2013-09-13-at-6.32.07-PM.jpg

the baytrail has the subsystem required for streaming digital audio,
in the I2S format (basically just a way of framing a bit stream). It
spits out this I2S stream to the outside world, and it's up to the
computer's implementers to do with it what they want.

Some devices will have a simple DAC and amp, others will have mixers
and switches to route audio to bluetooth, HDMI or speaker etc.

Toshiba chose the Realtek 5640 codec in our case, and I just stumbled
on its datasheet:
http://www.datasheetbank.com/datasheet/Realtek/ALC5640.html

The datasheet says the Realtek codec is entirely controlled by I2C.
I2C is a *slow* control bus, a bit like USB. I don't know if any GPIOs
are also used to control the audio circuits, such as headphone switch
detection. This is where having a wiring diagram of the Click Mini
would help to verify what I2C and GPIOs are connected to the audio
circuits.

Nicholas has pored over the Sharks Cove specs and thinks the TCM is
pretty similar, so hopefully we'll make some progress into making
sound work.


I submitted the TCM's DSDT table to this bug, in the hope that some
patches would work, but the one the guy responded with simply breaks
compilation.
https://bugzilla.kernel.org/show_bug.cgi?id=117141


please correct me if you think I'm wrong.