SAMA5D2 PIOBU GPIO support

modulename: gpio-sama5d2-piobu.ko

configname: CONFIG_GPIO_SAMA5D2_PIOBU

Linux Kernel Configuration
└─>Device Drivers
└─>GPIO Support
└─>Memory mapped GPIO drivers
└─>SAMA5D2 PIOBU GPIO support
In linux kernel since version 5 (release Date: 2019-03-03)  
Say yes here to use the PIOBU pins as GPIOs.

PIOBU pins on the SAMA5D2 can be used as GPIOs.
The difference from regular GPIOs is that they
maintain their value during backup/self-refresh.

source code:
drivers/gpio/gpio-sama5d2-piobu.c