Lines Matching full:pps
53 FEATURE(pps_sync, "Support usage of external PPS signal by kernel PLL");
178 * The following variables are used when a pulse-per-second (PPS) signal
181 * controlled by the PPS signal.
187 #define PPS_VALID 120 /* PPS signal watchdog max (s) */
188 #define PPS_MAXWANDER 100000 /* max PPS wander (ns/s) */
203 * PPS signal quality monitors
233 * PPS signal lost when either time or frequency synchronization in ntp_is_time_error()
240 * PPS jitter exceeded when time synchronization requested in ntp_is_time_error()
245 * PPS wander exceeded or calibration error when frequency in ntp_is_time_error()
587 * whether the PPS signal is operating. Note that the in ntp_update_second()
593 /* XXX even if PPS signal dies we should finish adjustment ? */ in ntp_update_second()
644 * time and frequency offset estimates for each call. If the kernel PPS
645 * discipline code is configured (PPS_SYNC), the PPS signal itself
649 * NTP). If the caller's time is far different than the PPS time, an
669 * source. If the PPS signal is present and enabled to in hardupdate()
670 * discipline the time, the PPS offset is used; otherwise, the in hardupdate()
688 * mode (PLL or FLL). If the PPS signal is present and enabled in hardupdate()
689 * to discipline the frequency, the PPS frequency is used; in hardupdate()
720 * hardpps() - discipline CPU clock oscillator to external PPS signal
722 * This routine is called at each PPS interrupt in order to discipline
723 * the CPU clock oscillator to the PPS signal. There are two independent
725 * frequency. The phase loop measures and grooms the PPS phase offset
727 * frequency loop averages successive PPS phase differences and
728 * calculates the PPS frequency offset, which is also processed by the
731 * nanoseconds at the on-time PPS signal transition.
739 * tsp - time at current PPS event
740 * delta_nsec - time elapsed between the previous and current PPS event
780 * current and previous PPS event measured directly by the timecounter. in hardpps()
788 * A three-stage median filter is used to help denoise the PPS in hardpps()
818 * Nominal jitter is due to PPS signal noise and interrupt in hardpps()
910 * The PPS frequency is recalculated and clamped to the maximum in hardpps()