[RFC v4 4/8] drm: Add Plane Gamma properties

[Uma Shankar]

Add plane gamma as blob property and size as a
range property.

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.

v4: Rebase

Signed-off-by: Uma Shankar <uma.shankar at intel.com>
---
 Documentation/gpu/drm-kms.rst       |  6 ++++++
 drivers/gpu/drm/drm_atomic.c        |  9 +++++++++
 drivers/gpu/drm/drm_atomic_helper.c |  3 +++
 drivers/gpu/drm/drm_plane.c         | 23 +++++++++++++++++++++++
 include/drm/drm_plane.h             | 22 ++++++++++++++++++++++
 5 files changed, 63 insertions(+)

diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst
index 16d6d8d..bcf9a86 100644
--- a/Documentation/gpu/drm-kms.rst
+++ b/Documentation/gpu/drm-kms.rst
@@ -563,6 +563,12 @@ Plane Color Management Properties
 .. kernel-doc:: drivers/gpu/drm/drm_plane.c
    :doc: ctm_property
 
+.. kernel-doc:: drivers/gpu/drm/drm_plane.c
+   :doc: gamma_lut_property
+
+.. kernel-doc:: drivers/gpu/drm/drm_plane.c
+   :doc: gamma_lut_size_property
+
 Tile Group Property
 -------------------
 
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index ddda935..8b0bf14 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -925,6 +925,13 @@ static int drm_atomic_plane_set_property(struct drm_plane *plane,
 					&replaced);
 		state->color_mgmt_changed |= replaced;
 		return ret;
+	} else if (property == plane->gamma_lut_property) {
+		ret = drm_atomic_replace_property_blob_from_id(dev,
+					&state->gamma_lut,
+					val, -1, sizeof(struct drm_color_lut),
+					&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);
@@ -998,6 +1005,8 @@ static int drm_atomic_plane_set_property(struct drm_plane *plane,
 			state->degamma_lut->base.id : 0;
 	} else if (property == plane->ctm_property) {
 		*val = (state->ctm) ? state->ctm->base.id : 0;
+	} else if (property == plane->gamma_lut_property) {
+		*val = (state->gamma_lut) ? state->gamma_lut->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 866181f..f524255 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -3618,6 +3618,8 @@ void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
 		drm_property_blob_get(state->degamma_lut);
 	if (state->ctm)
 		drm_property_blob_get(state->ctm);
+	if (state->gamma_lut)
+		drm_property_blob_put(state->gamma_lut);
 
 	state->color_mgmt_changed = false;
 }
@@ -3667,6 +3669,7 @@ void __drm_atomic_helper_plane_destroy_state(struct drm_plane_state *state)
 
 	drm_property_blob_put(state->degamma_lut);
 	drm_property_blob_put(state->ctm);
+	drm_property_blob_put(state->gamma_lut);
 }
 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 97520b1..d0bf10b 100644
--- a/drivers/gpu/drm/drm_plane.c
+++ b/drivers/gpu/drm/drm_plane.c
@@ -494,6 +494,15 @@ int drm_mode_plane_set_obj_prop(struct drm_plane *plane,
  *	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
+ *
+ * gamma_lut_property:
+ *	Blob property which allows a userspace to provide LUT values
+ *	to apply gamma/tone-mapping curve using the h/w plane gamma
+ *	processing engine, thereby making the content as non-linear
+ *	or to perform any tone mapping operation for HDR usecases.
+ *
+ * gamma_lut_size_property:
+ *	Range Property to indicate size of the plane gamma LUT.
  */
 int drm_plane_color_create_prop(struct drm_device *dev,
 				struct drm_plane *plane)
@@ -521,6 +530,20 @@ int drm_plane_color_create_prop(struct drm_device *dev,
 		return -ENOMEM;
 	plane->ctm_property = prop;
 
+	prop = drm_property_create(dev,
+			DRM_MODE_PROP_BLOB,
+			"PLANE_GAMMA_LUT", 0);
+	if (!prop)
+		return -ENOMEM;
+	plane->gamma_lut_property = prop;
+
+	prop = drm_property_create_range(dev,
+			DRM_MODE_PROP_IMMUTABLE,
+			"PLANE_GAMMA_LUT_SIZE", 0, UINT_MAX);
+	if (!prop)
+		return -ENOMEM;
+	plane->gamma_lut_size_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 5143277..fb466b1 100644
--- a/include/drm/drm_plane.h
+++ b/include/drm/drm_plane.h
@@ -191,6 +191,15 @@ struct drm_plane_state {
 	struct drm_property_blob *ctm;
 
 	/**
+	 * @gamma_lut:
+	 *
+	 * Lookup table for converting pixel data after the color conversion
+	 * matrix @ctm.  See drm_plane_enable_color_mgmt(). The blob (if not
+	 * NULL) is an array of &struct drm_color_lut_ext.
+	 */
+	struct drm_property_blob *gamma_lut;
+
+	/**
 	 * @commit: Tracks the pending commit to prevent use-after-free conditions,
 	 * and for async plane updates.
 	 *
@@ -713,6 +722,19 @@ struct drm_plane {
 	 * degamma LUT.
 	 */
 	struct drm_property *ctm_property;
+
+	/**
+	 * @plane_gamma_lut_property: Optional Plane property to set the LUT
+	 * used to convert the colors, after the CTM matrix, to the common
+	 * gamma space chosen for blending.
+	 */
+	struct drm_property *gamma_lut_property;
+
+	/**
+	 * @plane_gamma_lut_size_property: Optional Plane property for the size
+	 * of the gamma LUT as supported by the driver (read-only).
+	 */
+	struct drm_property *gamma_lut_size_property;
 };
 
 #define obj_to_plane(x) container_of(x, struct drm_plane, base)
-- 
1.9.1