drm: Conslidate blending properties in drm_blend.[hc]

Imo zpos, rotatation, blending eq (once we have it) and all that
should be in drm_blend.c, since those are all about how exactly the
pixels are rendered onto the CRTC's visible area. Also noticed that
one exported function accidentally ended up in drm_crtc_internal.h,
move it to the right place too.

Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1474448370-32227-3-git-send-email-daniel.vetter@ffwll.ch
diff --git a/drivers/gpu/drm/drm_blend.c b/drivers/gpu/drm/drm_blend.c
index 0a0b935..0b8e227 100644
--- a/drivers/gpu/drm/drm_blend.c
+++ b/drivers/gpu/drm/drm_blend.c
@@ -25,13 +25,62 @@
  */
 #include <drm/drmP.h>
 #include <drm/drm_atomic.h>
-#include <drm/drm_crtc.h>
+#include <drm/drm_blend.h>
 #include <linux/export.h>
 #include <linux/slab.h>
 #include <linux/sort.h>
 
 #include "drm_crtc_internal.h"
 
+struct drm_property *drm_mode_create_rotation_property(struct drm_device *dev,
+						       unsigned int supported_rotations)
+{
+	static const struct drm_prop_enum_list props[] = {
+		{ __builtin_ffs(DRM_ROTATE_0) - 1,   "rotate-0" },
+		{ __builtin_ffs(DRM_ROTATE_90) - 1,  "rotate-90" },
+		{ __builtin_ffs(DRM_ROTATE_180) - 1, "rotate-180" },
+		{ __builtin_ffs(DRM_ROTATE_270) - 1, "rotate-270" },
+		{ __builtin_ffs(DRM_REFLECT_X) - 1,  "reflect-x" },
+		{ __builtin_ffs(DRM_REFLECT_Y) - 1,  "reflect-y" },
+	};
+
+	return drm_property_create_bitmask(dev, 0, "rotation",
+					   props, ARRAY_SIZE(props),
+					   supported_rotations);
+}
+EXPORT_SYMBOL(drm_mode_create_rotation_property);
+
+/**
+ * drm_rotation_simplify() - Try to simplify the rotation
+ * @rotation: Rotation to be simplified
+ * @supported_rotations: Supported rotations
+ *
+ * Attempt to simplify the rotation to a form that is supported.
+ * Eg. if the hardware supports everything except DRM_REFLECT_X
+ * one could call this function like this:
+ *
+ * drm_rotation_simplify(rotation, DRM_ROTATE_0 |
+ *                       DRM_ROTATE_90 | DRM_ROTATE_180 |
+ *                       DRM_ROTATE_270 | DRM_REFLECT_Y);
+ *
+ * to eliminate the DRM_ROTATE_X flag. Depending on what kind of
+ * transforms the hardware supports, this function may not
+ * be able to produce a supported transform, so the caller should
+ * check the result afterwards.
+ */
+unsigned int drm_rotation_simplify(unsigned int rotation,
+				   unsigned int supported_rotations)
+{
+	if (rotation & ~supported_rotations) {
+		rotation ^= DRM_REFLECT_X | DRM_REFLECT_Y;
+		rotation = (rotation & DRM_REFLECT_MASK) |
+		           BIT((ffs(rotation & DRM_ROTATE_MASK) + 1) % 4);
+	}
+
+	return rotation;
+}
+EXPORT_SYMBOL(drm_rotation_simplify);
+
 /**
  * drm_plane_create_zpos_property - create mutable zpos property
  * @plane: drm plane