Add support for CEC notifiers, which is used to convey CEC physical address
information from video drivers to their CEC counterpart driver(s).
Based on an earlier version from Russell King:
https://patchwork.kernel.org/patch/9277043/
The cec_notifier is a reference counted object containing the CEC physical address
state of a video device.
When a new notifier is registered the current state will be reported to
that notifier at registration time.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
