drm/i915: Add 180 degree primary plane rotation support

drm/i915: Add 180 degree primary plane rotation support

Primary planes support 180 degree rotation. Expose the feature
through rotation drm property.

v2: Calculating linear/tiled offsets based on pipe source width and
height. Added 180 degree rotation support in ironlake_update_plane.

v3: Checking if CRTC is active before issueing update_plane. Added
wait for vblank to make sure we dont overtake page flips. Disabling
FBC since it does not work with rotated planes.

v4: Updated rotation checks for pending flips, fbc disable. Creating
rotation property only for Gen4 onwards. Property resetting as part
of lastclose.

v5: Resetting property in i915_driver_lastclose properly for planes
and crtcs. Fixed linear offset calculation that was off by 1 w.r.t
width in i9xx_update_plane and ironlake_update_plane. Removed tab
based indentation and unnecessary braces in intel_crtc_set_property
and intel_update_fbc. FBC and flip related checks should be done only
for valid crtcs.

v6: Minor nits in FBC disable checks for comments in intel_crtc_set_property
and positioning the disable code in intel_update_fbc.

v7: In case rotation property on inactive crtc is updated, we return
successfully printing debug log as crtc is inactive and only property change
is preserved.

v8: update_plane is changed to update_primary_plane, crtc->fb is changed to
crtc->primary->fb  and return value of update_primary_plane is ignored.

v9: added rotation property to primary plane instead of crtc. Removing reset
of rotation property from lastclose. rotation_property is moved to
drm_mode_config, so drm layer will take care of resetting. Adding updation of
fbc when rotation is set to 0. Allowing rotation only if value is
different than old one.

v10: Calling intel_primary_plane_setplane instead of update_primary_plane in
set_property(Daniel).

v11: Using same set_property function for both primary and sprite, Adding
primary plane specific code in the same function (Matt).

v12: Removing disabling/ enabling of fbc from set_property because it is done
from intel_pipe_set_base. Other formatting

v13: we need to call disable_fbc before changing the rotation to 180,
disable_fbc from intel_pipe_set_base gets called very late, that will
be used to re-enable fbc if rotation is set to 0 (Ville).

Testcase: igt/kms_rotation_crc

Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Sagar Kamble <sagar.a.kamble@intel.com>
Signed-off-by: Sonika Jindal <sonika.jindal@intel.com>
[danvet: Add FIXME to explain why we need the open-coded update_fbc
hunk to disable fbc when rotated 180 degree. And make checkpatch
happier.]
Acked-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>