help on USB programming of TWL4030A

Hi, ALL,

I want to study the code of the USB programming of TWL4030A OTG port
on beagle board, namely I want to know 1. how to read/write the
TWL4030A USB related registers through ULPI interface? 2. how to
transceive patterns through ULPI interface?

Can anyone point me to the right place so that I can be on the subject

Thank you very much