WM8994 GPIOs

modulename: gpio-wm8994.ko

configname: CONFIG_GPIO_WM8994

Linux Kernel Configuration
└─>Device Drivers
└─>GPIO Support
└─>MFD GPIO expanders
└─>WM8994 GPIOs
In linux kernel since version 2.6.34 (release Date: 2010-05-16)  
Say yes here to access the GPIO signals of WM8994 audio hub
CODECs from Wolfson Microelectronics.

source code:
drivers/gpio/gpio-wm8994.c