drm_crtc->fb may point to NULL, f.e X server will allocate a new fb
and assign it to the CRTC at startup, when X server exits, it will destroy
the allocated fb, making drm_crtc->fb points to NULL.
Put off registering new outputs with sysfs until they're properly configured,
or we may get duplicates if the type hasn't been set yet (as is the case with
SDVO initialization). This also means moving de-registration into the cleanup
function instead of output destroy, since the latter occurs during the normal
course of setup when an output isn't found (and therefore not registered with
sysfs yet.
This patch ties outputs, output properties and hotplug events into the
DRM core. Each output has a corresponding directory under the primary
DRM device (usually card0) containing dpms, edid, modes, and connection
status files.
New hotplug change events occur when outputs are added or hotplug events
are detected.
Allow mode to be set with fb_id set to -1, meaning set
the mode with the current fb (if we have one bound).
Allow intelfb to hook back up it's fb if modesetting
clears it (maybe temporary).
Move any crtc->fb related register changes to set_base
in intel_fb.
General intelfb cleanups.
so really want to get a list of modes per output not the global hammer list.
also we remove the mode ids and let the user pass back the full mode description
need to fix up add/remove mode for user modes now
This allow the user to retrieve a list of properties for an output.
Properties can either be 32-bit values or an enum with an associated name.
Range properties are to be supported.
This API is probably not all correct, I may make properties part of the general
resource get when I think about it some more.
So basically you can create properties and attached them to whatever outputs you want,
so it should be possible to create some generics and just attach them to every output.