[LinuxPPS] refclock_nmea patch

[Udo van den Heuvel]

Udo van den Heuvel wrote:
> I reworked stuff a bit.
> See the attached result which also open for comments.

Here's the same patch, but against the bare ntp source.
-------------- next part --------------
--- refclock_nmea.c.orig	2006-06-06 22:16:53.000000000 +0200
+++ refclock_nmea.c	2007-10-21 11:36:40.000000000 +0200
@@ -61,6 +61,7 @@
 # define DEVICE "COM%d:" 	/* COM 1 - 3 supported */
 #else
 # define DEVICE	"/dev/gps%d"	/* name of radio device */
+# define DEVICEPPS "/dev/pps%d" /* name of PPS radio device */
 #endif
 #define	SPEED232	B4800	/* uart speed (4800 bps) */
 #define	PRECISION	(-9)	/* precision assumed (about 2 ms) */
@@ -71,6 +72,7 @@
 #define RANGEGATE	500000	/* range gate (ns) */
 
 #define LENNMEA		75	/* min timecode length */
+#define LENPPS		PPS_MAX_NAME_LEN
 
 /*
  * Tables to compute the ddd of year form icky dd/mm timecode. Viva la
@@ -91,6 +93,7 @@
 	pps_params_t pps_params; /* pps parameters */
 	pps_info_t pps_info;	/* last pps data */
 	pps_handle_t handle;	/* pps handlebars */
+	int handle_created;	/* pps handle created flag */
 #endif /* HAVE_PPSAPI */
 };
 
@@ -139,6 +142,11 @@
 	register struct nmeaunit *up;
 	struct refclockproc *pp;
 	int fd;
+#ifdef PPS_HAVE_FINDPATH
+	char id[LENPPS] = "",
+	     path[LENPPS],
+	     link[LENPPS] = "/dev/gps0";    /* just a default device */
+#endif	/* PPS_HAVE_FINDPATH */
 	char device[20];
 
 	/*
@@ -230,15 +238,34 @@
 	 * Start the PPSAPI interface if it is there. Default to use
 	 * the assert edge and do not enable the kernel hardpps.
 	 */
+#ifdef PPS_HAVE_FINDPATH
 	if (time_pps_create(fd, &up->handle) < 0) {
-		up->handle = 0;
-		msyslog(LOG_ERR,
-		    "refclock_nmea: time_pps_create failed: %m");
-		return (1);
+
+		/* Try the alternare PPS device */
+		msyslog(LOG_ERR, "refclock_nmea: try alternate PPS device");
+                (void) sprintf(device, DEVICEPPS, unit);
+                fd = open(device, O_RDWR);
+                if (fd < 0)
+                	goto pps_error;
+                  
+		if (time_pps_create(fd, &up->handle) < 0)
+               		goto pps_error;
 	}
+	msyslog(LOG_INFO, "refclock_nmea: found PPS source \"%s\" at id #%d on \"%s\"", path, fd, id);
+	up->handle_created = ~0;
 	return(nmea_ppsapi(peer, 0, 0));
 #else
 	return (1);
+#endif /* PPS_HAVE_FINDPATH */
+
+pps_error:
+	/* No luck, no PPS unit available! */
+	up->handle = 0;
+	up->handle_created = 0;
+	msyslog(LOG_ERR, "refclock_nmea: alternate PPS device %s fail : %m", device);
+	return (1);
+#else
+	return (1);
 #endif /* HAVE_PPSAPI */
 }
 
@@ -257,8 +284,10 @@
 	pp = peer->procptr;
 	up = (struct nmeaunit *)pp->unitptr;
 #ifdef HAVE_PPSAPI
-	if (up->handle != 0)
+	if (up->handle_created) {
 		time_pps_destroy(up->handle);
+		up->handle_created = 0;
+	}
 #endif /* HAVE_PPSAPI */
 	io_closeclock(&pp->io);
 	free(up);
@@ -366,7 +395,7 @@
 	/*
 	 * Convert the timespec nanoseconds field to ntp l_fp units.
 	 */ 
-	if (up->handle == 0)
+	if (!up->handle_created)
 		return (0);
 	timeout.tv_sec = 0;
 	timeout.tv_nsec = 0;