drm/plane: Add COLOR PIPELINE property

We're adding a new enum COLOR PIPELINE property. This
property will have entries for each COLOR PIPELINE by
referencing the DRM object ID of the first drm_colorop
of the pipeline. 0 disables the entire COLOR PIPELINE.

Userspace can use this to discover the available color
pipelines, as well as set the desired one. The color
pipelines are programmed via properties on the actual
drm_colorop objects.

Reviewed-by: Simon Ser <[e-mail]>
Signed-off-by: Alex Hung <[e-mail]>
Signed-off-by: Harry Wentland <[e-mail]>
Reviewed-by: Daniel Stone <[e-mail]>
Reviewed-by: Melissa Wen <[e-mail]>
Reviewed-by: Sebastian Wick <[e-mail]>
Signed-off-by: Simon Ser <[e-mail]>
Link: https://patch.msgid.link/[e-mail]

drivers/gpu/drm/drm_atomic.c

···
 EXPORT_SYMBOL(drm_atomic_add_affected_planes);
 
 /**
+ * drm_atomic_add_affected_colorops - add colorops for plane
+ * @state: atomic state
+ * @plane: DRM plane
+ *
+ * This function walks the current configuration and adds all colorops
+ * currently used by @plane to the atomic configuration @state. This is useful
+ * when an atomic commit also needs to check all currently enabled colorop on
+ * @plane, e.g. when changing the mode. It's also useful when re-enabling a plane
+ * to avoid special code to force-enable all colorops.
+ *
+ * Since acquiring a colorop state will always also acquire the w/w mutex of the
+ * current plane for that colorop (if there is any) adding all the colorop states for
+ * a plane will not reduce parallelism of atomic updates.
+ *
+ * Returns:
+ * 0 on success or can fail with -EDEADLK or -ENOMEM. When the error is EDEADLK
+ * then the w/w mutex code has detected a deadlock and the entire atomic
+ * sequence must be restarted. All other errors are fatal.
+ */
+int
+drm_atomic_add_affected_colorops(struct drm_atomic_state *state,
+				 struct drm_plane *plane)
+{
+	struct drm_colorop *colorop;
+	struct drm_colorop_state *colorop_state;
+
+	WARN_ON(!drm_atomic_get_new_plane_state(state, plane));
+
+	drm_dbg_atomic(plane->dev,
+		       "Adding all current colorops for [PLANE:%d:%s] to %p\n",
+		       plane->base.id, plane->name, state);
+
+	drm_for_each_colorop(colorop, plane->dev) {
+		if (colorop->plane != plane)
+			continue;
+
+		colorop_state = drm_atomic_get_colorop_state(state, colorop);
+		if (IS_ERR(colorop_state))
+			return PTR_ERR(colorop_state);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_atomic_add_affected_colorops);
+
+/**
  * drm_atomic_check_only - check whether a given config would work
  * @state: atomic configuration to check
  *

drivers/gpu/drm/drm_atomic_state_helper.c

···
 			plane_state->color_range = val;
 	}
 
+	if (plane->color_pipeline_property) {
+		/* default is always NULL, i.e., bypass */
+		plane_state->color_pipeline = NULL;
+	}
+
 	if (plane->zpos_property) {
 		if (!drm_object_property_get_default_value(&plane->base,
 							   plane->zpos_property,

drivers/gpu/drm/drm_atomic_uapi.c

···
 EXPORT_SYMBOL(drm_atomic_set_fb_for_plane);
 
 /**
+ * drm_atomic_set_colorop_for_plane - set colorop for plane
+ * @plane_state: atomic state object for the plane
+ * @colorop: colorop to use for the plane
+ *
+ * Helper function to select the color pipeline on a plane by setting
+ * it to the first drm_colorop element of the pipeline.
+ */
+void
+drm_atomic_set_colorop_for_plane(struct drm_plane_state *plane_state,
+				 struct drm_colorop *colorop)
+{
+	struct drm_plane *plane = plane_state->plane;
+
+	if (colorop)
+		drm_dbg_atomic(plane->dev,
+			       "Set [COLOROP:%d] for [PLANE:%d:%s] state %p\n",
+			       colorop->base.id, plane->base.id, plane->name,
+			       plane_state);
+	else
+		drm_dbg_atomic(plane->dev,
+			       "Set [NOCOLOROP] for [PLANE:%d:%s] state %p\n",
+			       plane->base.id, plane->name, plane_state);
+
+	plane_state->color_pipeline = colorop;
+}
+EXPORT_SYMBOL(drm_atomic_set_colorop_for_plane);
+
+/**
  * drm_atomic_set_crtc_for_connector - set CRTC for connector
  * @conn_state: atomic state object for the connector
  * @crtc: CRTC to use for the connector
···
 		state->color_encoding = val;
 	} else if (property == plane->color_range_property) {
 		state->color_range = val;
+	} else if (property == plane->color_pipeline_property) {
+		/* find DRM colorop object */
+		struct drm_colorop *colorop = NULL;
+
+		colorop = drm_colorop_find(dev, file_priv, val);
+
+		if (val && !colorop)
+			return -EACCES;
+
+		drm_atomic_set_colorop_for_plane(state, colorop);
 	} else if (property == config->prop_fb_damage_clips) {
 		ret = drm_property_replace_blob_from_id(dev,
 					&state->fb_damage_clips,
···
 		*val = state->color_encoding;
 	} else if (property == plane->color_range_property) {
 		*val = state->color_range;
+	} else if (property == plane->color_pipeline_property) {
+		*val = (state->color_pipeline) ? state->color_pipeline->base.id : 0;
 	} else if (property == config->prop_fb_damage_clips) {
 		*val = (state->fb_damage_clips) ?
 			state->fb_damage_clips->base.id : 0;

drivers/gpu/drm/drm_plane.c

···
 	return 0;
 }
 EXPORT_SYMBOL(drm_plane_add_size_hints_property);
+
+/**
+ * drm_plane_create_color_pipeline_property - create a new color pipeline
+ * property
+ *
+ * @plane: drm plane
+ * @pipelines: list of pipelines
+ * @num_pipelines: number of pipelines
+ *
+ * Create the COLOR_PIPELINE plane property to specific color pipelines on
+ * the plane.
+ *
+ * RETURNS:
+ * Zero for success or -errno
+ */
+int drm_plane_create_color_pipeline_property(struct drm_plane *plane,
+					     const struct drm_prop_enum_list *pipelines,
+					     int num_pipelines)
+{
+	struct drm_prop_enum_list *all_pipelines;
+	struct drm_property *prop;
+	int len = 0;
+	int i;
+
+	all_pipelines = kcalloc(num_pipelines + 1,
+				sizeof(*all_pipelines),
+				GFP_KERNEL);
+
+	if (!all_pipelines) {
+		drm_err(plane->dev, "failed to allocate color pipeline\n");
+		return -ENOMEM;
+	}
+
+	/* Create default Bypass color pipeline */
+	all_pipelines[len].type = 0;
+	all_pipelines[len].name = "Bypass";
+	len++;
+
+	/* Add all other color pipelines */
+	for (i = 0; i < num_pipelines; i++, len++) {
+		all_pipelines[len].type = pipelines[i].type;
+		all_pipelines[len].name = pipelines[i].name;
+	}
+
+	prop = drm_property_create_enum(plane->dev, DRM_MODE_PROP_ATOMIC,
+					"COLOR_PIPELINE",
+					all_pipelines, len);
+	if (IS_ERR(prop)) {
+		kfree(all_pipelines);
+		return PTR_ERR(prop);
+	}
+
+	drm_object_attach_property(&plane->base, prop, 0);
+	plane->color_pipeline_property = prop;
+
+	kfree(all_pipelines);
+	return 0;
+}
+EXPORT_SYMBOL(drm_plane_create_color_pipeline_property);

include/drm/drm_atomic.h

···
 int __must_check
 drm_atomic_add_affected_planes(struct drm_atomic_state *state,
 			       struct drm_crtc *crtc);
+int __must_check
+drm_atomic_add_affected_colorops(struct drm_atomic_state *state,
+				 struct drm_plane *plane);
 
 int __must_check drm_atomic_check_only(struct drm_atomic_state *state);
 int __must_check drm_atomic_commit(struct drm_atomic_state *state);

include/drm/drm_atomic_uapi.h

···
 			      struct drm_crtc *crtc);
 void drm_atomic_set_fb_for_plane(struct drm_plane_state *plane_state,
 				 struct drm_framebuffer *fb);
+void drm_atomic_set_colorop_for_plane(struct drm_plane_state *plane_state,
+				      struct drm_colorop *colorop);
 int __must_check
 drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
 				  struct drm_crtc *crtc);

include/drm/drm_plane.h

···
 	struct drm_property *color_range_property;
 
 	/**
+	 * @color_pipeline_property:
+	 *
+	 * Optional "COLOR_PIPELINE" enum property for specifying
+	 * a color pipeline to use on the plane.
+	 */
+	struct drm_property *color_pipeline_property;
+
+	/**
 	 * @scaling_filter_property: property to apply a particular filter while
 	 * scaling.
 	 */
···
 				      const struct drm_plane_size_hint *hints,
 				      int num_hints);
 
+int drm_plane_create_color_pipeline_property(struct drm_plane *plane,
+					     const struct drm_prop_enum_list *pipelines,
+					     int num_pipelines);
 #endif