HelenOS sources

root/uspace/drv/bus/usb/xhci/

[..]
bus.c bus.h commands.c commands.h debug.c
debug.h device.c device.h doc/ endpoint.c
endpoint.h hc.c hc.h hw_struct/ isoch.c
isoch.h main.c rh.c rh.h scratchpad.c
scratchpad.h streams.c streams.h test/ transfers.c
transfers.h trb_ring.c trb_ring.h
[..]
HelenOS homepage, sources at GitHub