drm: Add drm_rotation_simplify()
authorVille Syrjälä <ville.syrjala@linux.intel.com>
Tue, 8 Jul 2014 05:01:56 +0000 (10:31 +0530)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Fri, 11 Jul 2014 21:44:20 +0000 (23:44 +0200)
commit3c9855f6dc1c68f7c4028f49bd8e3df7e4faae67
tree498d4cdc426a6ec39cbc3da562f75c3d20cbef25
parent07074006cd951f7a952512c57d60788ee7ea18db
drm: Add drm_rotation_simplify()

drm_rotation_simplify() can be used to eliminate unsupported rotation
flags. It will check if any unsupported flags are present, and if so
it will modify the rotation to an alternate form by adding 180 degrees
to rotation angle, and flipping the reflect x and y bits. The hope is
that this identity transform will eliminate the unsupported flags.

Of course that might not result in any more supported rotation, so
the caller is still responsible for checking the result afterwards.

Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Acked-by: Dave Airlie <airlied@linux.ie>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/drm_crtc.c
include/drm/drm_crtc.h