which driver for mmap-able battery-backed SRAM ?

[Philippe De Muyter]

Hi mtd experts,

I try to find the right driver for a memory-mapped battery-backed SRAM chip.
I have tried two drivers : 
	"mmio-sram"	drivers/misc/sram.c
and
	"mtd-ram"	drivers/mtd/chips/map_ram.c
but none of them provides me the expected interface : being able to mmap
it in a user program, and ensure that every write access to it happens
at the moment it is executed in the user program.

Is there already a driver that has those functionalities, or which one should
I enhance ?

TIA

-- 
Philippe De Muyter +32 2 6101532 Macq SA rue de l'Aeronef 2 B-1140 Bruxelles