drm/i915: Split pin mapping into per platform functions

Cleanup the code. Map the pins in accordance to
individual platforms rather than according to ports.
Create separate functions for platforms.

v2:
 - Add missing condition for CoffeeLake. Make platform
 specific functions static. Add function
 i915_ddc_pin_mapping().

v3:
 - Rename functions to x_port_to_ddc_pin() which directly
   indicates the purpose. Correct default return values on CNP
   and BXT. Rename i915_port_to_ to g4x_port_to since that was
   the first platform to run this. Correct code style. (Paulo)

Sugested-by Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Clinton Taylor <clinton.a.taylor@intel.com>
Signed-off-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1502927114-24012-1-git-send-email-anusha.srivatsa@intel.com

drivers/gpu/drm/i915/intel_hdmi.c

@@ -1843,38 +1843,83 @@ void intel_hdmi_handle_sink_scrambling(struct intel_encoder *encoder,
 	DRM_DEBUG_KMS("sink scrambling handled\n");
 }
 
-static u8 intel_hdmi_ddc_pin(struct drm_i915_private *dev_priv,
-			     enum port port)
+static u8 chv_port_to_ddc_pin(struct drm_i915_private *dev_priv, enum port port)
 {
-	const struct ddi_vbt_port_info *info =
-		&dev_priv->vbt.ddi_port_info[port];
 	u8 ddc_pin;
 
-	if (info->alternate_ddc_pin) {
-		DRM_DEBUG_KMS("Using DDC pin 0x%x for port %c (VBT)\n",
-			      info->alternate_ddc_pin, port_name(port));
-		return info->alternate_ddc_pin;
+	switch (port) {
+	case PORT_B:
+		ddc_pin = GMBUS_PIN_DPB;
+		break;
+	case PORT_C:
+		ddc_pin = GMBUS_PIN_DPC;
+		break;
+	case PORT_D:
+		ddc_pin = GMBUS_PIN_DPD_CHV;
+		break;
+	default:
+		MISSING_CASE(port);
+		ddc_pin = GMBUS_PIN_DPB;
+		break;
 	}
+	return ddc_pin;
+}
+
+static u8 bxt_port_to_ddc_pin(struct drm_i915_private *dev_priv, enum port port)
+{
+	u8 ddc_pin;
+
+	switch (port) {
+	case PORT_B:
+		ddc_pin = GMBUS_PIN_1_BXT;
+		break;
+	case PORT_C:
+		ddc_pin = GMBUS_PIN_2_BXT;
+		break;
+	default:
+		MISSING_CASE(port);
+		ddc_pin = GMBUS_PIN_1_BXT;
+		break;
+	}
+	return ddc_pin;
+}
+
+static u8 cnp_port_to_ddc_pin(struct drm_i915_private *dev_priv,
+			      enum port port)
+{
+	u8 ddc_pin;
 
 	switch (port) {
 	case PORT_B:
-		if (IS_GEN9_LP(dev_priv) || HAS_PCH_CNP(dev_priv))
 		ddc_pin = GMBUS_PIN_1_BXT;
-		else
-			ddc_pin = GMBUS_PIN_DPB;
 		break;
 	case PORT_C:
-		if (IS_GEN9_LP(dev_priv) || HAS_PCH_CNP(dev_priv))
 		ddc_pin = GMBUS_PIN_2_BXT;
-		else
-			ddc_pin = GMBUS_PIN_DPC;
 		break;
 	case PORT_D:
-		if (HAS_PCH_CNP(dev_priv))
 		ddc_pin = GMBUS_PIN_4_CNP;
-		else if (IS_CHERRYVIEW(dev_priv))
-			ddc_pin = GMBUS_PIN_DPD_CHV;
-		else
+		break;
+	default:
+		MISSING_CASE(port);
+		ddc_pin = GMBUS_PIN_1_BXT;
+		break;
+	}
+	return ddc_pin;
+}
+
+static u8 g4x_port_to_ddc_pin(struct drm_i915_private *dev_priv,
+			      enum port port)
+{
+	u8 ddc_pin;
+
+	switch (port) {
+	case PORT_B:
+		ddc_pin = GMBUS_PIN_DPB;
+		break;
+	case PORT_C:
+		ddc_pin = GMBUS_PIN_DPC;
+		break;
+	case PORT_D:
 		ddc_pin = GMBUS_PIN_DPD;
 		break;
 	default:
@@ -1882,6 +1927,30 @@ static u8 intel_hdmi_ddc_pin(struct drm_i915_private *dev_priv,
 		ddc_pin = GMBUS_PIN_DPB;
 		break;
 	}
+	return ddc_pin;
+}
+
+static u8 intel_hdmi_ddc_pin(struct drm_i915_private *dev_priv,
+			     enum port port)
+{
+	const struct ddi_vbt_port_info *info =
+		&dev_priv->vbt.ddi_port_info[port];
+	u8 ddc_pin;
+
+	if (info->alternate_ddc_pin) {
+		DRM_DEBUG_KMS("Using DDC pin 0x%x for port %c (VBT)\n",
+			      info->alternate_ddc_pin, port_name(port));
+		return info->alternate_ddc_pin;
+	}
+
+	if (IS_CHERRYVIEW(dev_priv))
+		ddc_pin = chv_port_to_ddc_pin(dev_priv, port);
+	else if (IS_GEN9_LP(dev_priv))
+		ddc_pin = bxt_port_to_ddc_pin(dev_priv, port);
+	else if (HAS_PCH_CNP(dev_priv))
+		ddc_pin = cnp_port_to_ddc_pin(dev_priv, port);
+	else
+		ddc_pin = g4x_port_to_ddc_pin(dev_priv, port);
 
 	DRM_DEBUG_KMS("Using DDC pin 0x%x for port %c (platform default)\n",
 		      ddc_pin, port_name(port));