This issue is for brain storming.

Currently we have several ways to implement board-specific components:

 1. Device API, via writing new code (for example LED)
 2. Device API, via external config (see device.audio).
 3. Args in test list (see usb-storage tests, also button tests)

There are pros and cons, but maybe we want to have some definition or guide line for what to use.

For example, LED & buttons are very similar - usually implemented via gpio or some sysfs node. What if we implement a generic GPIO driver and extend with configs (like audio) so that we can do something like dut.button.GetAllNames(), dut.button.GetStatus(name), dut.led.GetAllNames(), dut.led.GetStatus(name); then we can move the ectool/gpio/input driver code in pytests into board level and simply request the name of button/led in dargs.