PPM_SCALE_INV_SHIFT
#define PPM_SCALE_INV ((1LL << (PPM_SCALE_INV_SHIFT + NTP_SCALE_SHIFT)) / \
txc->ppsfreq = shift_right((ntpdata->pps_freq >> PPM_SCALE_INV_SHIFT) *
txc->freq = shift_right((ntpdata->time_freq >> PPM_SCALE_INV_SHIFT) *