drm/omap: dss: Move debug message and checks to connection handlers

The connectors, encoders and display duplicate the same debug messages
and connection checks in their omap_dss_device connect and disconnect
handlers. Move the code to the connect and disconnect wrappers.

To simplify the code the connect function returns -EBUSY unconditionally
if the device is already connected. This doesn't cause any change in
practice: the connect handler of displays is never called on a connected
device as it is only invoked during omapdrm initialization.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/displays/panel-nec-nl8048hl11.c

@@ -118,9 +118,6 @@ static int nec_8048_connect(struct omap_dss_device *dssdev)
 	struct omap_dss_device *in;
 	int r;
 
-	if (omapdss_device_is_connected(dssdev))
-		return 0;
-
 	in = omapdss_of_find_source_for_first_ep(dssdev->dev->of_node);
 	if (IS_ERR(in)) {
 		dev_err(dssdev->dev, "failed to find video source\n");
@@ -142,9 +139,6 @@ static void nec_8048_disconnect(struct omap_dss_device *dssdev)
 	struct panel_drv_data *ddata = to_panel_data(dssdev);
 	struct omap_dss_device *in = ddata->in;
 
-	if (!omapdss_device_is_connected(dssdev))
-		return;
-
 	omapdss_device_disconnect(in, dssdev);
 
 	omap_dss_put_device(in);