Scatter-gather driver for char device

Hello all:

    A colleague of mine wants to do a scatter-gather-type driver for a 
high-speed communications interface, but he can't find any Linux example 
code.  (Yes, there were plenty of examples for block devices, but not for 
char devices.)  They all seem to require a contiguous buffer.  He says the 
scatter-gather mode is easy to implement in NT.  Anybody have any knowledge 
of this, or know of a place we might look?
Thanks,

Vaughn Treude
Nakota Software, Inc.