pps/ptp: Allow PHC devices to adjust PPS events for known delay

Initial version by Stuart Hodgson <smhodgson@solarflare.com> Some PHC device drivers may deliver PPS events with a significant and variable delay, but still be able to measure precisely what that delay is. Add a pps_sub_ts() function for subtracting a delay from the timestamp(s) in a PPS event, and a PTP event type (PTP_CLOCK_PPSUSR) for which the caller provides a complete PPS event. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

pps/ptp: Allow PHC devices to adjust PPS events for known delay
Initial version by Stuart Hodgson <smhodgson@solarflare.com> Some PHC device drivers may deliver PPS events with a significant and variable delay, but still be able to measure precisely what that delay is. Add a pps_sub_ts() function for subtracting a delay from the timestamp(s) in a PPS event, and a PTP event type (PTP_CLOCK_PPSUSR) for which the caller provides a complete PPS event. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Ben Hutchings
1 parent ef2c7d7b59
Showing 3 changed files with 22 additions and 2 deletions Side-by-side Diff
drivers/ptp/ptp_clock.c
include/linux/pps_kernel.h
include/linux/ptp_clock_kernel.h
@@ -300,6 +300,11 @@
 		pps_get_ts(&evt);
 		pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);
 		break;
+
+	case PTP_CLOCK_PPSUSR:
+		pps_event(ptp->pps_source, &event->pps_times,
+			  PTP_PPS_EVENT, NULL);
+		break;
 	}
 }
 EXPORT_SYMBOL(ptp_clock_event);
@@ -116,5 +116,14 @@
  
 #endif /* CONFIG_NTP_PPS */
  
+/* Subtract known time delay from PPS event time(s) */
+static inline void pps_sub_ts(struct pps_event_time *ts, struct timespec delta)
+{
+	ts->ts_real = timespec_sub(ts->ts_real, delta);
+#ifdef CONFIG_NTP_PPS
+	ts->ts_raw = timespec_sub(ts->ts_raw, delta);
+#endif
+}
+
 #endif /* LINUX_PPS_KERNEL_H */
@@ -21,6 +21,7 @@
 #ifndef _PTP_CLOCK_KERNEL_H_
 #define _PTP_CLOCK_KERNEL_H_
  
+#include <linux/pps_kernel.h>
 #include <linux/ptp_clock.h>
  
  
@@ -110,6 +111,7 @@
 	PTP_CLOCK_ALARM,
 	PTP_CLOCK_EXTTS,
 	PTP_CLOCK_PPS,
+	PTP_CLOCK_PPSUSR,
 };
  
 /**
  
@@ -117,13 +119,17 @@
  *
  * @type:  One of the ptp_clock_events enumeration values.
  * @index: Identifies the source of the event.
- * @timestamp: When the event occured.
+ * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only).
+ * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).
  */
  
 struct ptp_clock_event {
 	int type;
 	int index;
-	u64 timestamp;
+	union {
+		u64 timestamp;
+		struct pps_event_time pps_times;
+	};
 };
  
 /**
...	...	@@ -300,6 +300,11 @@
300	300	pps_get_ts(&evt);
301	301	pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);
302	302	break;
	303	+
	304	+ case PTP_CLOCK_PPSUSR:
	305	+ pps_event(ptp->pps_source, &event->pps_times,
	306	+ PTP_PPS_EVENT, NULL);
	307	+ break;
303	308	}
304	309	}
305	310	EXPORT_SYMBOL(ptp_clock_event);
...	...	@@ -116,5 +116,14 @@
116	116
117	117	#endif /* CONFIG_NTP_PPS */
118	118
	119	+/* Subtract known time delay from PPS event time(s) */
	120	+static inline void pps_sub_ts(struct pps_event_time *ts, struct timespec delta)
	121	+{
	122	+ ts->ts_real = timespec_sub(ts->ts_real, delta);
	123	+#ifdef CONFIG_NTP_PPS
	124	+ ts->ts_raw = timespec_sub(ts->ts_raw, delta);
	125	+#endif
	126	+}
	127	+
119	128	#endif /* LINUX_PPS_KERNEL_H */
...	...	@@ -21,6 +21,7 @@
21	21	#ifndef _PTP_CLOCK_KERNEL_H_
22	22	#define _PTP_CLOCK_KERNEL_H_
23	23
	24	+#include <linux/pps_kernel.h>
24	25	#include <linux/ptp_clock.h>
25	26
26	27
...	...	@@ -110,6 +111,7 @@
110	111	PTP_CLOCK_ALARM,
111	112	PTP_CLOCK_EXTTS,
112	113	PTP_CLOCK_PPS,
	114	+ PTP_CLOCK_PPSUSR,
113	115	};
114	116
115	117	/**
116	118
...	...	@@ -117,13 +119,17 @@
117	119	*
118	120	* @type: One of the ptp_clock_events enumeration values.
119	121	* @index: Identifies the source of the event.
120		- * @timestamp: When the event occured.
	122	+ * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only).
	123	+ * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).
121	124	*/
122	125
123	126	struct ptp_clock_event {
124	127	int type;
125	128	int index;
126		- u64 timestamp;
	129	+ union {
	130	+ u64 timestamp;
	131	+ struct pps_event_time pps_times;
	132	+ };
127	133	};
128	134
129	135	/**