Can not find /dev/gpio node?

hello,

I use the lastest nios2 linux, I have tried to use altera gpio ip, well, the kernel support it, and it probed the gpio device during kernel boot, but when I try to check the /dev/gpio and /proc/devices, I can't find any thing about gpio, what's wrong ?

Shell I write c code to communicate with it or something else?

:(

regards