get_ptp_ts_val_u64
ns = (get_ptp_ts_val_u64(self, 0) +
(get_ptp_ts_val_u64(self, 1) << 16)) * NSEC_PER_SEC +
(get_ptp_ts_val_u64(self, 3) +
(get_ptp_ts_val_u64(self, 4) << 16));