drm/i915: Extract intel_panel_encoder_fixed_mode()

Apart from the EDID and VBT based mechanism we also sometimes
use the encoder's current mode as the panel fixed mode. We
currently have the same code for that duplicated in two places.
Let's unify.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220323182935.4701-8-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>

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

@@ -378,27 +378,6 @@ static const struct drm_encoder_funcs intel_dvo_enc_funcs = {
 	.destroy = intel_dvo_enc_destroy,
 };
 
-/*
- * Attempts to get a fixed panel timing for LVDS (currently only the i830).
- *
- * Other chips with DVO LVDS will need to extend this to deal with the LVDS
- * chip being on DVOB/C and having multiple pipes.
- */
-static struct drm_display_mode *
-intel_dvo_get_current_mode(struct intel_encoder *encoder)
-{
-	struct drm_display_mode *mode;
-
-	mode = intel_encoder_current_mode(encoder);
-	if (mode) {
-		DRM_DEBUG_KMS("using current (BIOS) mode: " DRM_MODE_FMT "\n",
-			      DRM_MODE_ARG(mode));
-		mode->type |= DRM_MODE_TYPE_PREFERRED;
-	}
-
-	return mode;
-}
-
 static enum port intel_dvo_port(i915_reg_t dvo_reg)
 {
 	if (i915_mmio_reg_equal(dvo_reg, DVOA))
@@ -541,6 +520,8 @@ void intel_dvo_init(struct drm_i915_private *dev_priv)
 
 		intel_connector_attach_encoder(intel_connector, intel_encoder);
 		if (dvo->type == INTEL_DVO_CHIP_LVDS) {
+			struct drm_display_mode *fixed_mode;
+
 			/*
 			 * For our LVDS chipsets, we should hopefully be able
 			 * to dig the fixed panel mode out of the BIOS data.
@@ -549,9 +530,10 @@ void intel_dvo_init(struct drm_i915_private *dev_priv)
 			 * headers, likely), so for now, just get the current
 			 * mode being output through DVO.
 			 */
-			intel_panel_init(intel_connector,
-					 intel_dvo_get_current_mode(intel_encoder),
-					 NULL);
+			fixed_mode = intel_panel_encoder_fixed_mode(intel_connector,
+								    intel_encoder);
+
+			intel_panel_init(intel_connector, fixed_mode, NULL);
 			intel_dvo->panel_wants_dither = true;
 		}
 

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

@@ -983,12 +983,7 @@ void intel_lvds_init(struct drm_i915_private *dev_priv)
 	 * on.  If so, assume that whatever is currently programmed is the
 	 * correct mode.
 	 */
-	fixed_mode = intel_encoder_current_mode(intel_encoder);
-	if (fixed_mode) {
-		drm_dbg_kms(&dev_priv->drm, "using current (BIOS) mode: " DRM_MODE_FMT "\n",
-			    DRM_MODE_ARG(fixed_mode));
-		fixed_mode->type |= DRM_MODE_TYPE_PREFERRED;
-	}
+	fixed_mode = intel_panel_encoder_fixed_mode(intel_connector, intel_encoder);
 
 	/* If we still don't have a mode after all that, give up. */
 	if (!fixed_mode)

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

@@ -292,6 +292,26 @@ intel_panel_vbt_sdvo_fixed_mode(struct intel_connector *connector)
 	return fixed_mode;
 }
 
+struct drm_display_mode *
+intel_panel_encoder_fixed_mode(struct intel_connector *connector,
+			       struct intel_encoder *encoder)
+{
+	struct drm_i915_private *i915 = to_i915(connector->base.dev);
+	struct drm_display_mode *fixed_mode;
+
+	fixed_mode = intel_encoder_current_mode(encoder);
+	if (!fixed_mode)
+		return NULL;
+
+	drm_dbg_kms(&i915->drm, "[CONNECTOR:%d:%s] using current (BIOS) mode: " DRM_MODE_FMT "\n",
+		    connector->base.base.id, connector->base.name,
+		    DRM_MODE_ARG(fixed_mode));
+
+	fixed_mode->type |= DRM_MODE_TYPE_PREFERRED;
+
+	return fixed_mode;
+}
+
 /* adjusted_mode has been preset to be the panel's fixed mode */
 static int pch_panel_fitting(struct intel_crtc_state *crtc_state,
 			     const struct drm_connector_state *conn_state)

drivers/gpu/drm/i915/display/intel_panel.h

@@ -16,6 +16,7 @@ struct drm_display_mode;
 struct drm_i915_private;
 struct intel_connector;
 struct intel_crtc_state;
+struct intel_encoder;
 
 int intel_panel_init(struct intel_connector *connector,
 		     struct drm_display_mode *fixed_mode,
@@ -50,5 +51,8 @@ struct drm_display_mode *
 intel_panel_vbt_lfp_fixed_mode(struct intel_connector *connector);
 struct drm_display_mode *
 intel_panel_vbt_sdvo_fixed_mode(struct intel_connector *connector);
+struct drm_display_mode *
+intel_panel_encoder_fixed_mode(struct intel_connector *connector,
+			       struct intel_encoder *encoder);
 
 #endif /* __INTEL_PANEL_H__ */