Keyspan PDA-type USB Serial

[Matt]

I have a Xircom PortGear USB->Serial device which is the same as an 
Entrega USB->Serial. This device operates (and attaches) with Keyspan 
PDA driver for linux, by downloading the appropriate firmware to the device.

We (FreeBSD) used to have support for these sorts of devices via the 
ezdownload utility, I think. It is no longer in ports, and does not 
compile on current.

Is there a driver for keyspan-pda type devices that I am missing? I have 
the actual firmware file the device requires. I know I should go buy a 
$6 PL2303-based device, but I hate trashing good hardware (build quality 
is excellent).

Thanks!
Matt