USB device for ppc440epx

[Leonid]

Hi:

does somebody have code example for USB 2.0 device implementation for
ppc440epx, preferably Mass Storage device, but any will do.

If not for ppc440epx (Sequoia board), ppc440ep (Yosemite) code will also
help (according to CPU user manual USB device interface is practically
the same).

If this is already present in Linux kernel tree (from what version?),
where it is located? 

Thanks,

Leonid.