drm/radeon/kms: enable hpd support

This enabled interrupt driven hpd support for all
radeon chips.  Assuming the hpd pin is wired up
correctly, the driver will generate uevents on
digital monitor connect and disconnect and retrain
DP monitors automatically.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
index 7328d15..cfa2ebb 100644
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -40,6 +40,26 @@
 				       struct drm_encoder *encoder,
 				       bool connected);
 
+void radeon_connector_hotplug(struct drm_connector *connector)
+{
+	struct drm_device *dev = connector->dev;
+	struct radeon_device *rdev = dev->dev_private;
+	struct radeon_connector *radeon_connector = to_radeon_connector(connector);
+
+	if (radeon_connector->hpd.hpd != RADEON_HPD_NONE)
+		radeon_hpd_set_polarity(rdev, radeon_connector->hpd.hpd);
+
+	if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort) {
+		if (radeon_dp_getsinktype(radeon_connector) == CONNECTOR_OBJECT_ID_DISPLAYPORT) {
+			if (radeon_dp_needs_link_train(radeon_connector)) {
+				if (connector->encoder)
+					dp_link_train(connector->encoder, connector);
+			}
+		}
+	}
+
+}
+
 static void radeon_property_change_mode(struct drm_encoder *encoder)
 {
 	struct drm_crtc *crtc = encoder->crtc;