Representing a rotary encoder input device

[Jason Thorpe <thorpej%me.com@localhost>]

Hey folks...

As part of a long-running hardware project I have been playing with, I'm experimenting with using a rotary encoder for input.  For reference, here is the Devicetree binding for rotary encoders:

	https://github.com/devicetree-org/devicetree-source/blob/master/Bindings/input/rotary-encoder.txt

Rotary encoders come in a bunch of different forms, of course... ranging from simple knobs with detents to devices similar to the original iPod click wheel.  Some include built-in push buttons (that signal a separate GPIO from the two GPIOs used to signal the rotary control itself).

Trying to think about the best way to represent such a device, I guess within wscons (they almost seem sort of like a 1-axis mouse, but I could be convinced otherwise).

Personally I'm seeing my use cases teetering towards using relative events (value selection that from 0-9 that wraps around back to 0, and also volume control that simply saturates at 0 or 100).  But I want to make sure I cover the absolute cases, as well.

Thoughts?

-- thorpej