Hi all,
  the WMI interfaces in some Lenovo Ideapad laptops provide notification
callbacks when the laptop orientation changes, reporting 4 different
values defining the new orientation.

I'd like to extend the ideapad-laptop driver with this information; but
how should it be reported to userspace? I initially thought of the input
subsystem, but I cannot find any suitable event codes; then I would
probably export it as a device under /sys, or are there better options?

Are there other devices which provide coarse orientation data to
userspace, which I might want to use as a reference?
I guess that at least some display screens have this feature.

TIA,
  Alberto

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