FROMLIST: drm: Extend color correction to support 3D-CLU

Extend the existing color management properties to support provision
of a 3D cubic look up table, allowing for color specific adjustments.

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Co-developed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Change-Id: I0bda1203a10f0df978b767d29baf06b390c0867e
Link:
https: //lore.kernel.org/dri-devel/20201221015730.28333-4-laurent.pinchart+renesas@ideasonboard.com/
Signed-off-by: Andy Yan <andy.yan@rock-chips.com>

drivers/gpu/drm/drm_atomic_helper.c

@@ -3544,6 +3544,9 @@ int drm_atomic_helper_legacy_gamma_set(struct drm_crtc *crtc,
 	replaced  = drm_property_replace_blob(&crtc_state->degamma_lut, NULL);
 	replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
 	replaced |= drm_property_replace_blob(&crtc_state->gamma_lut, blob);
+#if defined(CONFIG_ROCKCHIP_DRM_CUBIC_LUT)
+	replaced |= drm_property_replace_blob(&crtc_state->cubic_lut, NULL);
+#endif
 	crtc_state->color_mgmt_changed |= replaced;
 
 	ret = drm_atomic_commit(state);

drivers/gpu/drm/drm_atomic_state_helper.c

@@ -141,6 +141,10 @@ void __drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc,
 		drm_property_blob_get(state->ctm);
 	if (state->gamma_lut)
 		drm_property_blob_get(state->gamma_lut);
+#if defined(CONFIG_ROCKCHIP_DRM_CUBIC_LUT)
+	if (state->cubic_lut)
+		drm_property_blob_get(state->cubic_lut);
+#endif
 	state->mode_changed = false;
 	state->active_changed = false;
 	state->planes_changed = false;
@@ -213,6 +217,9 @@ void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc_state *state)
 	drm_property_blob_put(state->degamma_lut);
 	drm_property_blob_put(state->ctm);
 	drm_property_blob_put(state->gamma_lut);
+#if defined(CONFIG_ROCKCHIP_DRM_CUBIC_LUT)
+	drm_property_blob_put(state->cubic_lut);
+#endif
 }
 EXPORT_SYMBOL(__drm_atomic_helper_crtc_destroy_state);
 

drivers/gpu/drm/drm_atomic_uapi.c

@@ -459,6 +459,16 @@ static int drm_atomic_crtc_set_property(struct drm_crtc *crtc,
 					&replaced);
 		state->color_mgmt_changed |= replaced;
 		return ret;
+#if defined(CONFIG_ROCKCHIP_DRM_CUBIC_LUT)
+	} else if (property == config->cubic_lut_property) {
+		ret = drm_atomic_replace_property_blob_from_id(dev,
+					&state->cubic_lut,
+					val,
+					-1, sizeof(struct drm_color_lut),
+					&replaced);
+		state->color_mgmt_changed |= replaced;
+		return ret;
+#endif
 	} else if (property == config->prop_out_fence_ptr) {
 		s32 __user *fence_ptr = u64_to_user_ptr(val);
 
@@ -501,6 +511,10 @@ drm_atomic_crtc_get_property(struct drm_crtc *crtc,
 		*val = (state->ctm) ? state->ctm->base.id : 0;
 	else if (property == config->gamma_lut_property)
 		*val = (state->gamma_lut) ? state->gamma_lut->base.id : 0;
+#if defined(CONFIG_ROCKCHIP_DRM_CUBIC_LUT)
+	else if (property == config->cubic_lut_property)
+		*val = (state->cubic_lut) ? state->cubic_lut->base.id : 0;
+#endif
 	else if (property == config->prop_out_fence_ptr)
 		*val = 0;
 	else if (crtc->funcs->atomic_get_property)

drivers/gpu/drm/drm_color_mgmt.c

@@ -33,7 +33,7 @@
 /**
  * DOC: overview
  *
- * Color management or color space adjustments is supported through a set of 5
+ * Color management or color space adjustments is supported through a set of 7
  * properties on the &drm_crtc object. They are set up by calling
  * drm_crtc_enable_color_mgmt().
  *
@@ -60,7 +60,7 @@
  * “CTM”:
  *	Blob property to set the current transformation matrix (CTM) apply to
  *	pixel data after the lookup through the degamma LUT and before the
- *	lookup through the gamma LUT. The data is interpreted as a struct
+ *	lookup through the cubic LUT. The data is interpreted as a struct
  *	&drm_color_ctm.
  *
  *	Setting this to NULL (blob property value set to 0) means a
@@ -68,13 +68,40 @@
  *	boot-up state too. Drivers can access the blob for the color conversion
  *	matrix through &drm_crtc_state.ctm.
  *
+ * ”CUBIC_LUT”:
+ *	Blob property to set the cubic (3D) lookup table performing color
+ *	mapping after the transformation matrix and before the lookup through
+ *	the gamma LUT. Unlike the degamma and gamma LUTs that map color
+ *	components independently, the 3D LUT converts an input color to an
+ *	output color by indexing into the 3D table using the color components
+ *	as a 3D coordinate. The LUT is subsampled as 8-bit (or more) precision
+ *	would require too much storage space in the hardware, so the precision
+ *	of the color components is reduced before the look up, and the low
+ *	order bits may be used to interpolate between the nearest points in 3D
+ *	space.
+ *
+ *	The data is interpreted as an array of &struct drm_color_lut elements.
+ *	Hardware might choose not to use the full precision of the LUT
+ *	elements.
+ *
+ *	Setting this to NULL (blob property value set to 0) means the output
+ *	color is identical to the input color. This is generally the driver
+ *	boot-up state too. Drivers can access this blob through
+ *	&drm_crtc_state.cubic_lut.
+ *
+ * ”CUBIC_LUT_SIZE”:
+ *	Unsigned range property to give the size of the lookup table to be set
+ *	on the CUBIC_LUT property (the size depends on the underlying hardware).
+ *	If drivers support multiple LUT sizes then they should publish the
+ *	largest size, and sub-sample smaller sized LUTs appropriately.
+ *
  * “GAMMA_LUT”:
  *	Blob property to set the gamma lookup table (LUT) mapping pixel data
- *	after the transformation matrix to data sent to the connector. The
- *	data is interpreted as an array of &struct drm_color_lut elements.
- *	Hardware might choose not to use the full precision of the LUT elements
- *	nor use all the elements of the LUT (for example the hardware might
- *	choose to interpolate between LUT[0] and LUT[4]).
+ *	after the cubic LUT to data sent to the connector. The data is
+ *	interpreted as an array of &struct drm_color_lut elements. Hardware
+ *	might choose not to use the full precision of the LUT elements nor use
+ *	all the elements of the LUT (for example the hardware might choose to
+ *	interpolate between LUT[0] and LUT[4]).
  *
  *	Setting this to NULL (blob property value set to 0) means a
  *	linear/pass-thru gamma table should be used. This is generally the

drivers/gpu/drm/drm_mode_config.c

@@ -364,6 +364,22 @@ static int drm_mode_create_standard_properties(struct drm_device *dev)
 		return -ENOMEM;
 	dev->mode_config.gamma_lut_size_property = prop;
 
+#if defined(CONFIG_ROCKCHIP_DRM_CUBIC_LUT)
+	prop = drm_property_create(dev,
+			DRM_MODE_PROP_BLOB,
+			"CUBIC_LUT", 0);
+	if (!prop)
+		return -ENOMEM;
+	dev->mode_config.cubic_lut_property = prop;
+
+	prop = drm_property_create_range(dev,
+			DRM_MODE_PROP_IMMUTABLE,
+			"CUBIC_LUT_SIZE", 0, UINT_MAX);
+	if (!prop)
+		return -ENOMEM;
+	dev->mode_config.cubic_lut_size_property = prop;
+#endif
+
 	prop = drm_property_create(dev,
 				   DRM_MODE_PROP_IMMUTABLE | DRM_MODE_PROP_BLOB,
 				   "IN_FORMATS", 0);

drivers/gpu/drm/rockchip/Kconfig

@@ -20,6 +20,13 @@ config DRM_ROCKCHIP
 
 if DRM_ROCKCHIP
 
+config ROCKCHIP_DRM_CUBIC_LUT
+	bool "Support 3D cubic LUT"
+	depends on NO_GKI
+	help
+	  This add properties to support provision of a 3D cubic
+	  look up table, allowing for color specific adjustments.
+
 config ROCKCHIP_ANALOGIX_DP
 	bool "Rockchip specific extensions for Analogix DP driver"
 	help

include/drm/drm_crtc.h

@@ -287,7 +287,16 @@ struct drm_crtc_state {
 	 * NULL) is an array of &struct drm_color_lut.
 	 */
 	struct drm_property_blob *gamma_lut;
-
+#if defined(CONFIG_ROCKCHIP_DRM_CUBIC_LUT)
+	/**
+	 * @cubic_lut:
+	 *
+	 * Cubic Lookup table for converting pixel data. See
+	 * drm_crtc_enable_color_mgmt(). The blob (if not NULL) is a 3D array
+	 * of &struct drm_color_lut.
+	 */
+	struct drm_property_blob *cubic_lut;
+#endif
 	/**
 	 * @target_vblank:
 	 *

include/drm/drm_mode_config.h

@@ -794,6 +794,19 @@ struct drm_mode_config {
 	 */
 	struct drm_property *gamma_lut_size_property;
 
+#if defined(CONFIG_ROCKCHIP_DRM_CUBIC_LUT)
+	/**
+	 * @cubic_lut_property: Optional CRTC property to set the 3D LUT used to
+	 * convert color spaces.
+	 */
+	struct drm_property *cubic_lut_property;
+	/**
+	 * @cubic_lut_size_property: Optional CRTC property for the size of the
+	 * 3D LUT as supported by the driver (read-only).
+	 */
+	struct drm_property *cubic_lut_size_property;
+#endif
+
 	/**
 	 * @suggested_x_property: Optional connector property with a hint for
 	 * the position of the output on the host's screen.