linux-wandboard

MLK-16771 drm/imx: dpu: kms: Change to use a better KMS

This patch improves DPU KMS by the following means:
1) Wait for shadow registers being loaded in ->atomic_flush()
   to make sure there is no intermediate register values being
   loaded when doing atomic update.
2) Improve CRTC enablement/disablement sequences/configurations
   according to spec.
3) Remove the FGDM__PRIM framegen display mode from ->mode_set_nofb()
   and always use FGDM__SEC_ON_TOP mode so that we may prepare
   for introducing a safety stream solution in the future.
4) Better vblank on/off and vblank event handling, though there
   should be no essential improvements.
5) Some fixes for adding correct CRTC/plane/connector states
   in the full atomic state in dpu_drm_atomic_check().
6) Remove CRTC and plane states from the full atomic state where
   possible to improve atomic update performance.
7) Introduce a plane group mutex to protect plane source mask and
   vproc source mask.  This is a little bit superfluous due to
   the protection provided by the atomic helper, but just one of
   the DPU core itself.

The changes are in a bundle to avoid any unexpected drawbacks
of introducing them at a smaller granularity.

Signed-off-by: Liu Ying <victor.liu@nxp.com>