[RFC v3 3/8] drm: Add Plane CTM property

[Uma Shankar]

Add a blob property for plane CSC usage.

v2: Rebase

v3: Fixed Sean, Paul's review comments. Moved the property from
mode_config to drm_plane. Created a helper function to instantiate
these properties and removed from drm_mode_create_standard_properties
Added property documentation as suggested by Daniel, Vetter.

Signed-off-by: Uma Shankar <uma.shankar at intel.com>
---
 Documentation/gpu/drm-kms.rst       |  3 +++
 drivers/gpu/drm/drm_atomic.c        | 10 ++++++++++
 drivers/gpu/drm/drm_atomic_helper.c |  3 +++
 drivers/gpu/drm/drm_plane.c         | 12 ++++++++++++
 include/drm/drm_plane.h             | 16 ++++++++++++++++
 5 files changed, 44 insertions(+)

diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst
index 2c943f6..69b0b56 100644
--- a/Documentation/gpu/drm-kms.rst
+++ b/Documentation/gpu/drm-kms.rst
@@ -541,6 +541,9 @@ Plane Color Management Properties
 .. kernel-doc:: drivers/gpu/drm/drm_plane.c
    :doc: degamma_lut_size_property
 
+.. kernel-doc:: drivers/gpu/drm/drm_plane.c
+   :doc: ctm_property
+
 Tile Group Property
 -------------------
 
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 409c058..f86384fa 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -771,6 +771,14 @@ static int drm_atomic_plane_set_property(struct drm_plane *plane,
 					val, -1, &replaced);
 		state->color_mgmt_changed |= replaced;
 		return ret;
+	} else if (property == plane->ctm_property) {
+		ret = drm_atomic_replace_property_blob_from_id(dev,
+					&state->ctm,
+					val,
+					sizeof(struct drm_color_ctm),
+					&replaced);
+		state->color_mgmt_changed |= replaced;
+		return ret;
 	} else if (plane->funcs->atomic_set_property) {
 		return plane->funcs->atomic_set_property(plane, state,
 				property, val);
@@ -837,6 +845,8 @@ static int drm_atomic_plane_set_property(struct drm_plane *plane,
 	} else if (property == plane->degamma_lut_property) {
 		*val = (state->degamma_lut) ?
 			state->degamma_lut->base.id : 0;
+	} else if (property == plane->ctm_property) {
+		*val = (state->ctm) ? state->ctm->base.id : 0;
 	} else if (plane->funcs->atomic_get_property) {
 		return plane->funcs->atomic_get_property(plane, state, property, val);
 	} else {
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index d9384fd..76b4b41 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -3507,6 +3507,8 @@ void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
 
 	if (state->degamma_lut)
 		drm_property_reference_blob(state->degamma_lut);
+	if (state->ctm)
+		drm_property_reference_blob(state->ctm);
 	state->color_mgmt_changed = false;
 }
 EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);
@@ -3554,6 +3556,7 @@ void __drm_atomic_helper_plane_destroy_state(struct drm_plane_state *state)
 		drm_crtc_commit_put(state->commit);
 
 	drm_property_unreference_blob(state->degamma_lut);
+	drm_property_unreference_blob(state->ctm);
 }
 EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state);
 
diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
index 543a693..e635b63 100644
--- a/drivers/gpu/drm/drm_plane.c
+++ b/drivers/gpu/drm/drm_plane.c
@@ -485,6 +485,11 @@ int drm_mode_plane_set_obj_prop(struct drm_plane *plane,
  *
  * degamma_lut_size_property:
  *	Range Property to indicate size of the plane degamma LUT.
+ *
+ * ctm_property:
+ *	Blob property which allows a userspace to provide CTM coefficients
+ *	to do color space conversion or any other enhancement by doing a
+ *	matrix multiplication using the h/w CTM processing engine
  */
 int drm_plane_color_create_prop(struct drm_device *dev,
 				struct drm_plane *plane)
@@ -505,6 +510,13 @@ int drm_plane_color_create_prop(struct drm_device *dev,
 		return -ENOMEM;
 	plane->degamma_lut_size_property = prop;
 
+	prop = drm_property_create(dev,
+			DRM_MODE_PROP_BLOB,
+			"PLANE_CTM", 0);
+	if (!prop)
+		return -ENOMEM;
+	plane->ctm_property = prop;
+
 	return 0;
 }
 EXPORT_SYMBOL(drm_plane_color_create_prop);
diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
index 03291b1..35535c5 100644
--- a/include/drm/drm_plane.h
+++ b/include/drm/drm_plane.h
@@ -147,6 +147,14 @@ struct drm_plane_state {
 	struct drm_property_blob *degamma_lut;
 
 	/**
+	 * @ctm:
+	 *
+	 * Color transformation matrix. See drm_plane_enable_color_mgmt(). The
+	 * blob (if not NULL) is a &struct drm_color_ctm.
+	 */
+	struct drm_property_blob *ctm;
+
+	/**
 	 * @commit: Tracks the pending commit to prevent use-after-free conditions,
 	 * and for async plane updates.
 	 *
@@ -511,6 +519,7 @@ enum drm_plane_type {
  * @helper_private: mid-layer private data
  * @degamma_lut_property: Property for plane degamma LUT
  * @degamma_lut_size_property: Property for size of plane degamma LUT
+ * @ctm_property: Property for plane CTM matrix
  */
 struct drm_plane {
 	struct drm_device *dev;
@@ -614,6 +623,13 @@ struct drm_plane {
 	 * size of the degamma LUT as supported by the driver (read-only).
 	 */
 	struct drm_property *degamma_lut_size_property;
+
+	/**
+	 * @plane_ctm_property: Optional Plane property to set the
+	 * matrix used to convert colors after the lookup in the
+	 * degamma LUT.
+	 */
+	struct drm_property *ctm_property;
 };
 
 #define obj_to_plane(x) container_of(x, struct drm_plane, base)
-- 
1.9.1