Here is a patch adding the PID for the FT232RL to ftdi_sio. The patch
generates a warning during compilation because get_ftdi_divisor doesn't
explicitly handle the FT232RL with this patch, so I guess you don't want
to use it in its current state. It is all I could come up with with the
knowledge I have of the drivers at the moment, though, and I hope you
can have some use for it at least. It works fine with my DLP-TILT with
an FT232RL.