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>
This commit is contained in:
Ville Syrjälä
2014-07-08 10:31:56 +05:30
committed by Daniel Vetter
parent 07074006cd
commit 3c9855f6dc
2 changed files with 32 additions and 0 deletions

View File

@@ -1115,6 +1115,8 @@ extern int drm_format_vert_chroma_subsampling(uint32_t format);
extern const char *drm_get_format_name(uint32_t format);
extern struct drm_property *drm_mode_create_rotation_property(struct drm_device *dev,
unsigned int supported_rotations);
extern unsigned int drm_rotation_simplify(unsigned int rotation,
unsigned int supported_rotations);
/* Helpers */