And it will be removed in 2020. See https://www.kernel.org/doc/Documentation/ABI/obsolete/sysfs-gpio And the new https://www.kernel.org/doc/Documentation/ABI/testing/gpio-cdev You can also see this talk from the last Embedded Linux Conference Europe (posted yesterday by the Linux Foundation): https://www.youtube.com/watch?v=cdTLewJCL1Y&list=PLbzoR-pLrL6pISWAq-1cXP4_UZAyRtesk&index=56