kernel/Documentation/ABI/obsolete/sysfs-gpio
.. .. @@ -11,7 +11,9 @@ 11 11 Kernel code may export it for complete or partial access. 12 12 13 13 GPIOs are identified as they are inside the kernel, using integers in 14 - the range 0..INT_MAX. See Documentation/gpio for more information.14 + the range 0..INT_MAX. See Documentation/admin-guide/gpio for more information.15 +16 + ::15 17 16 18 /sys/class/gpio 17 19 /export ... asks the kernel to export a GPIO to userspace