drm_of_encoder_active_endpoint_id
ret = drm_of_encoder_active_endpoint_id(dp->dev->of_node, &dp->encoder.encoder);
mux = drm_of_encoder_active_endpoint_id(dsi->dev->of_node,
ret = drm_of_encoder_active_endpoint_id(hdmi->dev->of_node, encoder);
mux = drm_of_encoder_active_endpoint_id(hdmi->dev->of_node, &hdmi->encoder.encoder);
ret = drm_of_encoder_active_endpoint_id(lvds->dev->of_node, encoder);
vop = drm_of_encoder_active_endpoint_id(lvds->dev->of_node, encoder);