drm/amd/display: add plane blend LUT and TF support

Map plane blend properties to DPP blend gamma. Plane blend is a
post-3D LUT curve that linearizes color space for blending. It may be
defined by a user-blob LUT and/or predefined transfer function. As
hardcoded curve (ROM) is not supported on blend gamma, we use AMD color
module to fill parameters when setting non-linear TF with empty LUT.

v2:
- rename DRM TFs to AMDGPU TFs
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Joshua Ashton <joshua@froggi.es>
Signed-off-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -8271,6 +8271,7 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state,
 			bundle->surface_updates[planes_count].hdr_mult = dc_plane->hdr_mult;
 			bundle->surface_updates[planes_count].func_shaper = dc_plane->in_shaper_func;
 			bundle->surface_updates[planes_count].lut3d_func = dc_plane->lut3d_func;
+			bundle->surface_updates[planes_count].blend_tf = dc_plane->blend_tf;
 		}
 
 		amdgpu_dm_plane_fill_dc_scaling_info(dm->adev, new_plane_state,

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c

@@ -733,6 +733,35 @@ static int amdgpu_dm_atomic_shaper_lut(const struct drm_color_lut *shaper_lut,
 	return ret;
 }
 
+static int amdgpu_dm_atomic_blend_lut(const struct drm_color_lut *blend_lut,
+				       bool has_rom,
+				       enum dc_transfer_func_predefined tf,
+				       uint32_t blend_size,
+				       struct dc_transfer_func *func_blend)
+{
+	int ret = 0;
+
+	if (blend_size || tf != TRANSFER_FUNCTION_LINEAR) {
+		/*
+		 * DRM plane gamma LUT or TF means we are linearizing color
+		 * space before blending (similar to degamma programming). As
+		 * we don't have hardcoded curve support, or we use AMD color
+		 * module to fill the parameters that will be translated to HW
+		 * points.
+		 */
+		func_blend->type = TF_TYPE_DISTRIBUTED_POINTS;
+		func_blend->tf = tf;
+		func_blend->sdr_ref_white_level = SDR_WHITE_LEVEL_INIT_VALUE;
+
+		ret = __set_input_tf(func_blend, blend_lut, blend_size);
+	} else {
+		func_blend->type = TF_TYPE_BYPASS;
+		func_blend->tf = TRANSFER_FUNCTION_LINEAR;
+	}
+
+	return ret;
+}
+
 /**
  * amdgpu_dm_verify_lut3d_size - verifies if 3D LUT is supported and if user
  * shaper and 3D LUTs match the hw supported size
@@ -1071,8 +1100,9 @@ amdgpu_dm_plane_set_color_properties(struct drm_plane_state *plane_state,
 {
 	struct dm_plane_state *dm_plane_state = to_dm_plane_state(plane_state);
 	enum amdgpu_transfer_function shaper_tf = AMDGPU_TRANSFER_FUNCTION_DEFAULT;
-	const struct drm_color_lut *shaper_lut, *lut3d;
-	uint32_t shaper_size, lut3d_size;
+	enum amdgpu_transfer_function blend_tf = AMDGPU_TRANSFER_FUNCTION_DEFAULT;
+	const struct drm_color_lut *shaper_lut, *lut3d, *blend_lut;
+	uint32_t shaper_size, lut3d_size, blend_size;
 	int ret;
 
 	dc_plane_state->hdr_mult = dc_fixpt_from_s3132(dm_plane_state->hdr_mult);
@@ -1088,12 +1118,30 @@ amdgpu_dm_plane_set_color_properties(struct drm_plane_state *plane_state,
 					  amdgpu_tf_to_dc_tf(shaper_tf),
 					  shaper_size,
 					  dc_plane_state->in_shaper_func);
-	if (ret)
+	if (ret) {
 		drm_dbg_kms(plane_state->plane->dev,
 			    "setting plane %d shaper LUT failed.\n",
 			    plane_state->plane->index);
 
 		return ret;
+	}
+
+	blend_tf = dm_plane_state->blend_tf;
+	blend_lut = __extract_blob_lut(dm_plane_state->blend_lut, &blend_size);
+	blend_size = blend_lut != NULL ? blend_size : 0;
+
+	ret = amdgpu_dm_atomic_blend_lut(blend_lut, false,
+					 amdgpu_tf_to_dc_tf(blend_tf),
+					 blend_size, dc_plane_state->blend_tf);
+	if (ret) {
+		drm_dbg_kms(plane_state->plane->dev,
+			    "setting plane %d gamma lut failed.\n",
+			    plane_state->plane->index);
+
+		return ret;
+	}
+
+	return 0;
 }
 
 /**