Known Hardware Info Edit
The sound chip is a Wolfson Micro WM8750, which interfaces with the processor over the I2C (for control) and I2S (for audio) buses. The I2C address of the WM8750 is 0x1A.
Links to further information (which may or may not be of use) can be found on the Handhelds.org wiki.
Current Status Edit
Working :) Code is in my Github kernel repo.