I think this PDF describes the same OTC controller as the rpi one:
http://rockchip.fr/RK312X%20TRM/chapter-26-usb-otg-2-0.pdf
I think this PDF describes the same OTC controller as the rpi one:
http:// rockchip. fr/RK312X% 20TRM/chapter- 26-usb- otg-2-0. pdf