AT91 pinctrl driver

modulename: pinctrl-at91.ko

configname: CONFIG_PINCTRL_AT91

Linux Kernel Configuration
└─>Device Drivers
└─>Pin controllers
└─>Device Tree and Open Firmware support
└─>AT91 pinctrl driver
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Say Y here to enable the at91 pinctrl driver

source code: