How to interface AC'97 codec driver with kernel ?

[Pratik Singhal]

Hello  all,

I am writing the driver for AC'97 controller present in Allwinner A10 SoC
as a part of my Google summer of code Project.  I have understood the
theoretical aspects of AC'97 and know "what" to code, but I am unable to
understand , how to interface the code with FreeBSD kernel.

For ex, when making changes in the mmc driver, it was very clear that the
high-level file sys/dev/mmc/mmc.c will call the methods defined in our
implementation of mmc driver,

In the case of AC'97, what all files should I look at ? I have so far
looked at sys/dev/sound/pcm/ directory, but can't seem to understand much
there.
Also,how does FreeBSD control the AC-link , which will be used to control
various parameters related to AC'97 codec I/O ?

I am new to working with sound at this low level, so there might be some
trivial things which I may have missed.
Any help would be very valuable for timely completion of project


Thanks,
Pratik Singhal