drm: Introduce "Virtual" connectors and encoders

This will allow us to attach various properties specific to virtual
monitors in the future.

Note that we don't export an EDID property for "Virtual" connectors.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_crtc.c

@@ -162,6 +162,7 @@ static struct drm_conn_prop_enum_list drm_connector_enum_list[] =
 	{ DRM_MODE_CONNECTOR_HDMIB, "HDMI-B", 0 },
 	{ DRM_MODE_CONNECTOR_TV, "TV", 0 },
 	{ DRM_MODE_CONNECTOR_eDP, "eDP", 0 },
+	{ DRM_MODE_CONNECTOR_VIRTUAL, "Virtual", 0},
 };
 
 static struct drm_prop_enum_list drm_encoder_enum_list[] =
@@ -170,6 +171,7 @@ static struct drm_prop_enum_list drm_encoder_enum_list[] =
 	{ DRM_MODE_ENCODER_TMDS, "TMDS" },
 	{ DRM_MODE_ENCODER_LVDS, "LVDS" },
 	{ DRM_MODE_ENCODER_TVDAC, "TV" },
+	{ DRM_MODE_ENCODER_VIRTUAL, "Virtual" },
 };
 
 char *drm_get_encoder_name(struct drm_encoder *encoder)
@@ -463,8 +465,10 @@ void drm_connector_init(struct drm_device *dev,
 	list_add_tail(&connector->head, &dev->mode_config.connector_list);
 	dev->mode_config.num_connector++;
 
+	if (connector_type != DRM_MODE_CONNECTOR_VIRTUAL)
 		drm_connector_attach_property(connector,
-				      dev->mode_config.edid_property, 0);
+					      dev->mode_config.edid_property,
+					      0);
 
 	drm_connector_attach_property(connector,
 				      dev->mode_config.dpms_property, 0);

include/drm/drm_mode.h

@@ -125,6 +125,7 @@ struct drm_mode_crtc {
 #define DRM_MODE_ENCODER_TMDS	 2
 #define DRM_MODE_ENCODER_LVDS	 3
 #define DRM_MODE_ENCODER_TVDAC	 4
+#define DRM_MODE_ENCODER_VIRTUAL 5
 
 struct drm_mode_get_encoder {
 	__u32 encoder_id;
@@ -162,6 +163,7 @@ struct drm_mode_get_encoder {
 #define DRM_MODE_CONNECTOR_HDMIB	12
 #define DRM_MODE_CONNECTOR_TV		13
 #define DRM_MODE_CONNECTOR_eDP		14
+#define DRM_MODE_CONNECTOR_VIRTUAL      15
 
 struct drm_mode_get_connector {