drm/i915/rkl: Add DDC pin mapping

The pin mapping for the final two outputs varies according to which PCH
is present on the platform:  with TGP the pins are remapped into the TC
range, whereas with CMP they stay in the traditional combo output range.

Bspec: 49181
Cc: Aditya Swarup <aditya.swarup@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200603211529.3005059-9-matthew.d.roper@intel.com

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

@@ -3082,6 +3082,24 @@ static u8 mcc_port_to_ddc_pin(struct drm_i915_private *dev_priv, enum port port)
 	return ddc_pin;
 }
 
+static u8 rkl_port_to_ddc_pin(struct drm_i915_private *dev_priv, enum port port)
+{
+	enum phy phy = intel_port_to_phy(dev_priv, port);
+
+	WARN_ON(port == PORT_C);
+
+	/*
+	 * Pin mapping for RKL depends on which PCH is present.  With TGP, the
+	 * final two outputs use type-c pins, even though they're actually
+	 * combo outputs.  With CMP, the traditional DDI A-D pins are used for
+	 * all outputs.
+	 */
+	if (INTEL_PCH_TYPE(dev_priv) >= PCH_TGP && phy >= PHY_C)
+		return GMBUS_PIN_9_TC1_ICP + phy - PHY_C;
+
+	return GMBUS_PIN_1_BXT + phy;
+}
+
 static u8 g4x_port_to_ddc_pin(struct drm_i915_private *dev_priv,
 			      enum port port)
 {
@@ -3119,7 +3137,9 @@ static u8 intel_hdmi_ddc_pin(struct intel_encoder *encoder)
 		return ddc_pin;
 	}
 
-	if (HAS_PCH_MCC(dev_priv))
+	if (IS_ROCKETLAKE(dev_priv))
+		ddc_pin = rkl_port_to_ddc_pin(dev_priv, port);
+	else if (HAS_PCH_MCC(dev_priv))
 		ddc_pin = mcc_port_to_ddc_pin(dev_priv, port);
 	else if (INTEL_PCH_TYPE(dev_priv) >= PCH_ICP)
 		ddc_pin = icl_port_to_ddc_pin(dev_priv, port);