1 files changed, 45 insertions, 17 deletions

diff --git a/xpp/xbus-pcm.h b/xpp/xbus-pcm.h
index 79d0078..3265f68 100644
--- a/xpp/xbus-pcm.h
+++ b/xpp/xbus-pcm.h
@@ -40,27 +40,50 @@ enum sync_mode {
 };
 
 /*
- * A generic timing source. Encapsulates all sampling
- * logic, average and standard deviation computation,
- * tick_rate computation.
- *
- * Each xbus has embedded instance.
- * Also there is a global instance for external reference
- * syncing (e.g: from zaptel)
+ * Abstract representation of timestamp.
+ * It would (eventually) replace the hard-coded
+ * timeval structs so we can migrate to better
+ * time representations.
+ */
+struct xpp_timestamp {
+	struct timeval	tv;
+};
+
+/*
+ * A ticker encapsulates the timing information of some
+ * abstract tick source. The following tickers are used:
+ *   - Each xbus has an embedded ticker.
+ *   - There is one global zaptel_ticker to represent ticks
+ *     of external zaptel card (in case we want to sync
+ *     from other zaptel devices).
+ */
+struct xpp_ticker {		/* for rate calculation */
+	int			count;
+	int			cycle;
+	struct xpp_timestamp	first_sample;
+	struct xpp_timestamp	last_sample;
+	int			tick_period;	/* usec/tick */
+	spinlock_t		lock;
+};
+
+/*
+ * xpp_drift represent the measurements of the offset between an
+ * xbus ticker to a reference ticker.
  */
-struct xpp_timing {
-	const char		*name;
-	struct timeval		timing_val;
-	unsigned long		timing_count;
-	long			accumulated_usec;
-	long			accumulated_usec_sqr;
-	int			tick_avg;
-	int			tick_stddev;
+struct xpp_drift {
+	int			wanted_offset;		/* fixed */
+	int			delta_tick;		/* from ref_ticker */
+	int			lost_ticks;		/* occurances */
+	int			lost_tick_count;
+	int			delta_max;
+	int			delta_min;
+	int			median;			/* (max + min) / 2	*/
+	int			jitter;			/* max - min		*/
+	int			calc_drift;
 	spinlock_t		lock;
-	unsigned int		tick_rate;
 };
 
-void xpp_timing_init(struct xpp_timing *timing, const char *name);
+void xpp_drift_init(xbus_t *xbus);
 
 static inline long usec_diff(const struct timeval *tv1, const struct timeval *tv2)
 {
@@ -100,6 +123,11 @@ extern int xpp_ec;
 #define	xpp_ec	0
 #endif
 
+#ifdef	DEBUG_PCMTX
+extern int	pcmtx;
+extern int	pcmtx_chan;
+#endif
+
 #endif	/* __KERNEL__ */
 
 #endif	/* XBUS_PCM_H */