drm/i915: Extract intel_dp_output_format()

Refactor the output_format calculation into a helper so that
we can reuse it for mode validation as well.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200917214335.3569-1-ville.syrjala@linux.intel.comReviewed-by: Vandita Kulkarni <vandita.kulkarni@intel.com>

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

@@ -592,6 +592,22 @@ static u8 intel_dp_dsc_get_slice_count(struct intel_dp *intel_dp,
 	return 0;
 }
 
+static enum intel_output_format
+intel_dp_output_format(struct drm_connector *connector,
+		       const struct drm_display_mode *mode)
+{
+	struct intel_dp *intel_dp = intel_attached_dp(to_intel_connector(connector));
+	const struct drm_display_info *info = &connector->display_info;
+
+	if (!drm_mode_is_420_only(info, mode))
+		return INTEL_OUTPUT_FORMAT_RGB;
+
+	if (intel_dp->dfp.ycbcr_444_to_420)
+		return INTEL_OUTPUT_FORMAT_YCBCR444;
+	else
+		return INTEL_OUTPUT_FORMAT_YCBCR420;
+}
+
 static bool intel_dp_hdisplay_bad(struct drm_i915_private *dev_priv,
 				  int hdisplay)
 {
@@ -2430,27 +2446,20 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
 }
 
 static int
-intel_dp_ycbcr420_config(struct intel_dp *intel_dp,
-			 struct intel_crtc_state *crtc_state,
+intel_dp_ycbcr420_config(struct intel_crtc_state *crtc_state,
 			 const struct drm_connector_state *conn_state)
 {
 	struct drm_connector *connector = conn_state->connector;
-	const struct drm_display_info *info = &connector->display_info;
 	const struct drm_display_mode *adjusted_mode =
 		&crtc_state->hw.adjusted_mode;
 
 	if (!connector->ycbcr_420_allowed)
 		return 0;
 
-	if (!drm_mode_is_420_only(info, adjusted_mode))
-		return 0;
+	crtc_state->output_format = intel_dp_output_format(connector, adjusted_mode);
 
-	if (intel_dp->dfp.ycbcr_444_to_420) {
-		crtc_state->output_format = INTEL_OUTPUT_FORMAT_YCBCR444;
+	if (crtc_state->output_format != INTEL_OUTPUT_FORMAT_YCBCR420)
 		return 0;
-	}
-
-	crtc_state->output_format = INTEL_OUTPUT_FORMAT_YCBCR420;
 
 	return intel_pch_panel_fitting(crtc_state, conn_state);
 }
@@ -2710,8 +2719,7 @@ intel_dp_compute_config(struct intel_encoder *encoder,
 	if (lspcon->active)
 		lspcon_ycbcr420_config(&intel_connector->base, pipe_config);
 	else
-		ret = intel_dp_ycbcr420_config(intel_dp, pipe_config,
-					       conn_state);
+		ret = intel_dp_ycbcr420_config(pipe_config, conn_state);
 	if (ret)
 		return ret;