Anyone know the SuperI/O found in Dell XPS m1530 (and possible m1330/m1730) laptops?

[andrew at ishiboo.com (Andrew Paprocki)]

Running sensors-detect finds an unknown National Semiconductor chip
with ID 0xfc11 at 0x4e. I haven't been able to find any info on what
kind of chip this is by looking through datasheets. Is there any work
being done to support these laptops already?

Thanks,
-Andrew