I am working on the TWI driver for the AT91SAM9263 controller. When I am trying to access the TWI registers it gives me the segmentation fault error as follows

Unable to handle kernel paging request at virtual address fef88010.

will anyone please guide me how to calculate the virtual adress for the TWI
I have done the calculations as follows

#define L_TWI_VIRT_BASE (TWI_PHY_BASE - L_IO_PHY_BASE) + L_IO_VIRT_BASE

where

TWI_PHY_BASE 0xFFF88000
L_IO_PHY_BASE 0xFFF78000
L_IO_VIRT_BASE 0xFEF78000

Thank you

It's very difficult to guess what are you doing and how.
Please provide more details and the source code.

Hi there

> will anyone please guide me how to calculate the virtual adress for the TWI

The base virtual address (for the register set) should not be calculated using constants.
You should be calling request_mem_region() and ioremap().

What does your driver's init look like?

Regards