3 files changed, 50 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index f44aae124771..22bb0dd9a911 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -220,3 +220,32 @@ void hsw_fdi_link_train(struct drm_crtc *crtc)
 
         DRM_DEBUG_KMS("FDI train done.\n");
 }
+
+/* For DDI connections, it is possible to support different outputs over the
+ * same DDI port, such as HDMI or DP or even VGA via FDI. So we don't know by
+ * the time the output is detected what exactly is on the other end of it. This
+ * function aims at providing support for this detection and proper output
+ * configuration.
+ */
+void intel_ddi_init(struct drm_device *dev, enum port port)
+{
+        /* For now, we don't do any proper output detection and assume that we
+         * handle HDMI only */
+
+        switch(port){
+        case PORT_A:
+                /* We don't handle eDP and DP yet */
+                DRM_DEBUG_DRIVER("Found digital output on DDI port A\n");
+                break;
+        /* Assume that the  ports B, C and D are working in HDMI mode for now */
+        case PORT_B:
+        case PORT_C:
+        case PORT_D:
+                intel_hdmi_init(dev, DDI_BUF_CTL(port));
+                break;
+        default:
+                DRM_DEBUG_DRIVER("No handlers defined for port %d, skipping DDI initialization\n",
+                                port);
+                break;
+        }
+}
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index f1bb2e2ec173..1a06f97e73f8 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6474,7 +6474,26 @@ static void intel_setup_outputs(struct drm_device *dev)
 
         intel_crt_init(dev);
 
-        if (HAS_PCH_SPLIT(dev)) {
+        if (IS_HASWELL(dev)) {
+                int found;
+
+                /* Haswell uses DDI functions to detect digital outputs */
+                found = I915_READ(DDI_BUF_CTL_A) & DDI_INIT_DISPLAY_DETECTED;
+                /* DDI A only supports eDP */
+                if (found)
+                        intel_ddi_init(dev, PORT_A);
+
+                /* DDI B, C and D detection is indicated by the SFUSE_STRAP
+                 * register */
+                found = I915_READ(SFUSE_STRAP);
+
+                if (found & SFUSE_STRAP_DDIB_DETECTED)
+                        intel_ddi_init(dev, PORT_B);
+                if (found & SFUSE_STRAP_DDIC_DETECTED)
+                        intel_ddi_init(dev, PORT_C);
+                if (found & SFUSE_STRAP_DDID_DETECTED)
+                        intel_ddi_init(dev, PORT_D);
+        } else if (HAS_PCH_SPLIT(dev)) {
                 int found;
 
                 if (I915_READ(HDMIB) & PORT_DETECTED) {
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 0ad1bb383976..fd96ffbf501b 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -448,6 +448,7 @@ extern void intel_write_eld(struct drm_encoder *encoder,
 extern void intel_cpt_verify_modeset(struct drm_device *dev, int pipe);
 extern void intel_prepare_ddi(struct drm_device *dev);
 extern void hsw_fdi_link_train(struct drm_crtc *crtc);
+extern void intel_ddi_init(struct drm_device *dev, enum port port);
 
 /* For use by IVB LP watermark workaround in intel_sprite.c */
 extern void intel_update_watermarks(struct drm_device *dev);