PTP_RTC_SUB_NANOSEC
[PTP_RTC_SUB_NANOSEC] = 0x060C,
[PTP_RTC_SUB_NANOSEC] = 0x0502,
ret = ksz_read8(dev, regs[PTP_RTC_SUB_NANOSEC], &phase);
ret = ksz_write16(dev, regs[PTP_RTC_SUB_NANOSEC], PTP_RTC_0NS);