hi i am new to device drivers ,we have ported linux to arm board s3c2440
now i need to do some i/o work on board ,,so i wrote a driver for it to access the memory location of the i/o
register i have assigned the register address 0x4c00000c (PORTB address as in datasheet)
by using the function request_mem_region
now when i am doing outb operation to this address it is saying that

"Unable to handle kernel paging request at virtual address 4c00000c"

i googled this problem and i found that i am referring to physical address ,which i should not do
so how to map this physical address of PORTB ?
or else how can i access the PORTB register?

plz suggest me something as i am eager to see my board led glowing as my wish