drm/atomic: Add MODE_ID property

Atomic modesetting: now with modesetting support.

v2: Moved drm_atomic_set_mode_prop_for_crtc from previous patch; removed
    state->active fiddling, documented return code. Changed property
    type to DRM_MODE_PROP_BLOB.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Tested-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/drm_crtc.c

@@ -688,6 +688,7 @@ int drm_crtc_init_with_planes(struct drm_device *dev, struct drm_crtc *crtc,
 
 	if (drm_core_check_feature(dev, DRIVER_ATOMIC)) {
 		drm_object_attach_property(&crtc->base, config->prop_active, 0);
+		drm_object_attach_property(&crtc->base, config->prop_mode_id, 0);
 	}
 
 	return 0;
@@ -1454,6 +1455,13 @@ static int drm_mode_create_standard_properties(struct drm_device *dev)
 		return -ENOMEM;
 	dev->mode_config.prop_active = prop;
 
+	prop = drm_property_create(dev,
+			DRM_MODE_PROP_ATOMIC | DRM_MODE_PROP_BLOB,
+			"MODE_ID", 0);
+	if (!prop)
+		return -ENOMEM;
+	dev->mode_config.prop_mode_id = prop;
+
 	return 0;
 }