GPIOLIB Support

Has anyone attempted to enable GPIOLIB support? Trying to enable support for the pcf8575 I2C GPIO expander requires GPIOLIB to be enabled, however, I am getting compilation errors referring to:

/linux-2.6/drivers/gpio/gpiolib.c:57: error: `ARCH_NR_GPIOS' undeclared here (not in a function)

After doing alot of searching I find that ARCH_WANT_OPTIONAL_GPIOLIB must be selected witch I have done via:

config ALTERA_DE2

bool "Altera DE2 Development board support"

depends on NIOS2

select ARCH_WANT_OPTIONAL_GPIOLIB

help

Support for the Altera Cyclone Development board. Includes

support for 10/100 ethernet, FLASH, SDRAM, VGA, I2C.

There seems to be more required but I am not sure where?

I am using the 2.6.28.2 kernel.

Thank you.