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>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 8ea9821261ab..9bae13394e5b 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/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);