Good question - I'd like to know the answer myself........
I think...I think, that recognising the USB will be no problem, but you need a module to recognise and control the serial, so you MUST find one that has LINUX drivers. I suspect the chance of this is vanishingly small, as most hardware suppliers support LINUX grudgingly at best, and only where the hardware is reasonably expensive (video cards). Otherwise, you need someone who writes a driver for their own satisfaction. I think the market segment is very small for USB/serial conversion - most people who care would just make sure their laptop came with USB. You and I probably should have done the same
I hope someone more experienced has a better idea.
best wishes
Jim