Mediatek GPIO Support

modulename: gpio-mt7621.ko

configname: CONFIG_GPIO_MT7621

Linux Kernel Configuration
└─>Device Drivers
└─>Staging drivers
└─>Mediatek GPIO Support
In linux kernel since version 4.2 (release Date: 2015-08-30)  
Say yes here to support the Mediatek SoC GPIO device

source code:
drivers/staging/mt7621-gpio/gpio-mt7621.c