Removable flash storage

[Brad Beveridge]

Hello all.
I am working with a device that has 3 nand flash slots, two are internal 
and not removable, one is external and is removable.
We currently have a single driver that registers partitions on each card 
at kernel boot time.  All three cards work, and we use yaffs as a 
filesystem on top of MTD.
I am trying to come up with a clean way of allowing the external card to 
be inserted/removed at runtime.
One solution is to have a seperate nand driver for that card & build it 
as a module, then simply modprobe/rmmod.  However, that solution isn't 
so great because we then have two driver source files that are 
essentially the same.
We also thought that a /proc based solution might work, where you write 
"eject 3" or something to /proc/mtd.

What will play nicest with MTD as it stands?  If I need to break the 
driver up, is there any suggestions for minimising code duplication?

Cheers
Brad