static const GpsInterface  mtk_gps_inf = {
    sizeof(GpsInterface),
    gpsinf_init,
    gpsinf_start,
    gpsinf_stop,
    gpsinf_cleanup,
    gpsinf_inject_time,
    gpsinf_inject_location,
    gpsinf_delete_aiding_data,
    gpsinf_set_position_mode,
    gpsinf_get_extension,
};