/sys/class/gpio/... (sysfs interface)

modulename: gpiolib-sysfs.ko


Linux Kernel Configuration
└─>Device Drivers
└─>GPIO Support
└─>/sys/class/gpio/... (sysfs interface)
In linux kernel since version 2.6.27 (release Date: 2008-10-09)  
Say Y here to add the legacy sysfs interface for GPIOs.

This ABI is deprecated. If you want to use GPIO from userspace,
use the character device /dev/gpiochipN with the appropriate
ioctl() operations instead.

source code: