8260 fcc_enet driver newbie question

[Vijay Kumar]

I was going through the fcc_enet driver
(linux-2.6.12.2/arch/ppc/8260_io/fcc_enet.c).

The driver accesses the CPM memory map using 
immap = (cpm2_map_t *)CPM_MAP_ADDR;

There is also a global variable cpm2_immr defined in
arch/ppc/syslib/cpm2_common.c

If I were to write a new driver which one should I use
to access the CPM memory map?

Vijay