Make gpio drivers fully replaceable by each other. Prepare general GPIO class for reuse with module classes. Ideally compatible with some external drivers (eg. for Odroids gpio pins) <bountysource-plugin> --- Want to back this issue? **[Post a bounty on it!](https://www.bountysource.com/issues/56032523-unify-methods-of-gpio-drivers?utm_campaign=plugin&utm_content=tracker%2F563374&utm_medium=issues&utm_source=github)** We accept bounties via [Bountysource](https://www.bountysource.com/?utm_campaign=plugin&utm_content=tracker%2F563374&utm_medium=issues&utm_source=github). </bountysource-plugin>