+size_t drv_num_planes_from_modifier(struct driver *drv, uint32_t format, uint64_t modifier)
+{
+ size_t planes = drv_num_planes_from_format(format);
+
+ /* Disallow unsupported formats. */
+ if (!planes)
+ return 0;
+
+ if (drv->backend->num_planes_from_modifier && modifier != DRM_FORMAT_MOD_INVALID)
+ return drv->backend->num_planes_from_modifier(drv, format, modifier);
+
+ return planes;
+}
+