drm/i915/skl: Enable DDI-E

There are OEMs using DDI-E out there,
so let's enable it.

Unfortunately there is no detection bit for DDI-E
So we need to rely on VBT for that.

I also need to give credits to Xiong since before seing
his approach to check info->support_* I was creating an ugly
vbt->ddie_sfuse_strap in order to propagate the ddi presence info

v2: Rebased as last patch in the series. since all other patches
in this series are needed for anything working propperly on DDI-E.

Credits-to: "Zhang, Xiong Y" <xiong.y.zhang@intel.com>
Cc: "Zhang, Xiong Y" <xiong.y.zhang@intel.com>
Reviewed-by: Xiong Zhang <xiong.y.zhang@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/intel_bios.c

@@ -909,19 +909,19 @@ static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,
 	/* Each DDI port can have more than one value on the "DVO Port" field,
 	 * so look for all the possible values for each port and abort if more
 	 * than one is found. */
-	int dvo_ports[][2] = {
-		{DVO_PORT_HDMIA, DVO_PORT_DPA},
-		{DVO_PORT_HDMIB, DVO_PORT_DPB},
-		{DVO_PORT_HDMIC, DVO_PORT_DPC},
-		{DVO_PORT_HDMID, DVO_PORT_DPD},
-		{DVO_PORT_CRT, -1 /* Port E can only be DVO_PORT_CRT */ },
+	int dvo_ports[][3] = {
+		{DVO_PORT_HDMIA, DVO_PORT_DPA, -1},
+		{DVO_PORT_HDMIB, DVO_PORT_DPB, -1},
+		{DVO_PORT_HDMIC, DVO_PORT_DPC, -1},
+		{DVO_PORT_HDMID, DVO_PORT_DPD, -1},
+		{DVO_PORT_CRT, DVO_PORT_HDMIE, DVO_PORT_DPE},
 	};
 
 	/* Find the child device to use, abort if more than one found. */
 	for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
 		it = dev_priv->vbt.child_dev + i;
 
-		for (j = 0; j < 2; j++) {
+		for (j = 0; j < 3; j++) {
 			if (dvo_ports[port][j] == -1)
 				break;
 

drivers/gpu/drm/i915/intel_bios.h

@@ -775,6 +775,8 @@ int intel_parse_bios(struct drm_device *dev);
 #define DVO_PORT_DPC	8
 #define DVO_PORT_DPD	9
 #define DVO_PORT_DPA	10
+#define DVO_PORT_DPE	11
+#define DVO_PORT_HDMIE	12
 #define DVO_PORT_MIPIA	21
 #define DVO_PORT_MIPIB	22
 #define DVO_PORT_MIPIC	23

drivers/gpu/drm/i915/intel_display.c

@@ -13960,6 +13960,15 @@ static void intel_setup_outputs(struct drm_device *dev)
 			intel_ddi_init(dev, PORT_C);
 		if (found & SFUSE_STRAP_DDID_DETECTED)
 			intel_ddi_init(dev, PORT_D);
+		/*
+		 * On SKL we don't have a way to detect DDI-E so we rely on VBT.
+		 */
+		if (IS_SKYLAKE(dev) &&
+		    (dev_priv->vbt.ddi_port_info[PORT_E].supports_dp ||
+		     dev_priv->vbt.ddi_port_info[PORT_E].supports_dvi ||
+		     dev_priv->vbt.ddi_port_info[PORT_E].supports_hdmi))
+			intel_ddi_init(dev, PORT_E);
+
 	} else if (HAS_PCH_SPLIT(dev)) {
 		int found;
 		dpd_is_edp = intel_dp_is_edp(dev, PORT_D);