PR_CLOCK_DRIFT_C
hellcreek_ptp_write(hellcreek, negative, PR_CLOCK_DRIFT_C);
hellcreek_ptp_write(hellcreek, 0x00, PR_CLOCK_DRIFT_C);
hellcreek_ptp_write(hellcreek, 0x00, PR_CLOCK_DRIFT_C);
hellcreek_ptp_write(hellcreek, addendh, PR_CLOCK_DRIFT_C);
hellcreek_ptp_write(hellcreek, addendl, PR_CLOCK_DRIFT_C);