Some display controllers can be hardware programmed to show non-black
colors for pixels that are either not covered by any plane or are
exposed through transparent regions of higher planes.  This feature can
help reduce memory bandwidth usage, e.g. in compositors managing a UI
with a solid background color while using smaller planes to render the
remaining content.

To support this capability, introduce the BACKGROUND_COLOR standard DRM
mode property, which can be attached to a CRTC through the
drm_crtc_attach_background_color_property() helper function.

Additionally, define a 64-bit ARGB format value to be built with the
help of a dedicated drm_argb64() utility macro.  Individual color
components can be extracted with desired precision using the
corresponding DRM_ARGB64_*() macros.

Co-developed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>

VOP2 allows configuring the background color of each video output port.

Since a previous patch introduced the BACKGROUND_COLOR CRTC property,
which defaults to solid black, take it into account when programming the
hardware.

Note that only the 10 least significant bits of each color component are
used, as this is the maximum precision supported by the display
controller.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>

Since a previous patch introduced the BACKGROUND_COLOR CRTC property,
which defaults to solid black, take it into account when programming the
hardware.
The exact registers used varies between the hardware generations,
but is supported by all of them.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

When adding the register definitions for the GEN_6D hardware, 6
defines managed to get added twice.

Remove that duplication.

Fixes: 3ca2940 ("drm/vc4: hvs: Add in support for 2712 D-step.")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>