drm/i915: Add Plane color encoding support for YCBCR_BT2020

Currently the plane property doesn't have support for YCBCR_BT2020,
which enables the corresponding color conversion mode on plane CSC.
Enabling the plane property for the planes for GLK & ICL+ platforms.
Also as per spec, update the Plane Color CSC from YUV601_TO_RGB709
to YUV601_TO_RGB601.

V2: Enabling support for YCBCT_BT2020 for HDR planes on
    platforms GLK & ICL

V3: Refined the condition check to handle GLK & ICL+ HDR planes
    Also added BT2020 handling in glk_plane_color_ctl.

V4: Combine If-else into single If

V5: Drop the checking for HDR planes and enable YCBCR_BT2020
    for platforms GLK & ICL+.

V6: As per Spec, update PLANE_COLOR_CSC_MODE_YUV601_TO_RGB709
    to PLANE_COLOR_CSC_MODE_YUV601_TO_RGB601 as per Ville's
    feedback.

V7: Rebased

Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Kishore Kadiyala <kishore.kadiyala@intel.com>
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200601073544.11291-1-kishore.kadiyala@intel.com

drivers/gpu/drm/i915/display/intel_display.c

@@ -4812,11 +4812,18 @@ u32 glk_plane_color_ctl(const struct intel_crtc_state *crtc_state,
 	plane_color_ctl |= glk_plane_color_ctl_alpha(plane_state);
 
 	if (fb->format->is_yuv && !icl_is_hdr_plane(dev_priv, plane->id)) {
-		if (plane_state->hw.color_encoding == DRM_COLOR_YCBCR_BT709)
+		switch (plane_state->hw.color_encoding) {
+		case DRM_COLOR_YCBCR_BT709:
 			plane_color_ctl |= PLANE_COLOR_CSC_MODE_YUV709_TO_RGB709;
-		else
-			plane_color_ctl |= PLANE_COLOR_CSC_MODE_YUV601_TO_RGB709;
-
+			break;
+		case DRM_COLOR_YCBCR_BT2020:
+			plane_color_ctl |=
+				PLANE_COLOR_CSC_MODE_YUV2020_TO_RGB2020;
+			break;
+		default:
+			plane_color_ctl |=
+				PLANE_COLOR_CSC_MODE_YUV601_TO_RGB601;
+		}
 		if (plane_state->hw.color_range == DRM_COLOR_YCBCR_FULL_RANGE)
 			plane_color_ctl |= PLANE_COLOR_YUV_RANGE_CORRECTION_DISABLE;
 	} else if (fb->format->is_yuv) {

drivers/gpu/drm/i915/display/intel_sprite.c

@@ -3061,6 +3061,7 @@ skl_universal_plane_create(struct drm_i915_private *dev_priv,
 	struct intel_plane *plane;
 	enum drm_plane_type plane_type;
 	unsigned int supported_rotations;
+	unsigned int supported_csc;
 	const u64 *modifiers;
 	const u32 *formats;
 	int num_formats;
@@ -3135,9 +3136,13 @@ skl_universal_plane_create(struct drm_i915_private *dev_priv,
 					   DRM_MODE_ROTATE_0,
 					   supported_rotations);
 
+	supported_csc = BIT(DRM_COLOR_YCBCR_BT601) | BIT(DRM_COLOR_YCBCR_BT709);
+
+	if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv))
+		supported_csc |= BIT(DRM_COLOR_YCBCR_BT2020);
+
 	drm_plane_create_color_properties(&plane->base,
-					  BIT(DRM_COLOR_YCBCR_BT601) |
-					  BIT(DRM_COLOR_YCBCR_BT709),
+					  supported_csc,
 					  BIT(DRM_COLOR_YCBCR_LIMITED_RANGE) |
 					  BIT(DRM_COLOR_YCBCR_FULL_RANGE),
 					  DRM_COLOR_YCBCR_BT709,

drivers/gpu/drm/i915/i915_reg.h

@@ -6932,7 +6932,7 @@ enum {
 #define   PLANE_COLOR_INPUT_CSC_ENABLE		(1 << 20) /* ICL+ */
 #define   PLANE_COLOR_PIPE_CSC_ENABLE		(1 << 23) /* Pre-ICL */
 #define   PLANE_COLOR_CSC_MODE_BYPASS			(0 << 17)
-#define   PLANE_COLOR_CSC_MODE_YUV601_TO_RGB709		(1 << 17)
+#define   PLANE_COLOR_CSC_MODE_YUV601_TO_RGB601		(1 << 17)
 #define   PLANE_COLOR_CSC_MODE_YUV709_TO_RGB709		(2 << 17)
 #define   PLANE_COLOR_CSC_MODE_YUV2020_TO_RGB2020	(3 << 17)
 #define   PLANE_COLOR_CSC_MODE_RGB709_TO_RGB2020	(4 << 17)