PTP_EGR_TS_FIFO_THRESH_MASK
val &= ~(PTP_EGR_TS_FIFO_SIG_BYTES_MASK | PTP_EGR_TS_FIFO_THRESH_MASK);
#define PTP_EGR_TS_FIFO_THRESH(x) (((x) << 8) & PTP_EGR_TS_FIFO_THRESH_MASK)