I have finally managed to successfully porting the USB Host controller code by M. Elizabeth Scott from Spin to C++.
Took me a while to make it working due to a very nasty issue with the received bytes count calculation that was very hard to debug.
The attached zip file contains the USBHost class and two demo applications: enumerate.elf shows the informations about the attached device, and hid.elf that polls a keyboard or mouse and shows the data from it.
Can be compiled with propeller-gcc using the included Makefile and uploaded and run on the Propeller with propeller-load:
propeller-load -p /dev/ttyUSB0 -t -r enumerate.elf
propeller-load -p /dev/ttyUSB0 -t -r hid.elf
The code is not fully tested and I'm sure it needs some more revisions so use with cautions.
Hope you enjoy!