[LinuxPPS] Re: [Bug 610] Generic NMEA GPS Receiver driver w/
PPS expects PPS after NMEA data
Udo van den Heuvel
udovdh at xs4all.nl
Mon Oct 29 17:26:58 CET 2007
Rodolfo Giometti wrote:
> In this situation you should do something like:
Like the attached patch?
Is this better?
-------------- next part --------------
--- org.ntp-4.2.4p2/ntpd/refclock_nmea.c 2006-06-06 22:16:53.000000000 +0200
+++ ntp-4.2.4p2/ntpd/refclock_nmea.c 2007-10-29 17:25:57.000000000 +0100
@@ -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/gpspps%d" /* name of alternate 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
@@ -230,13 +232,32 @@
* Start the PPSAPI interface if it is there. Default to use
* the assert edge and do not enable the kernel hardpps.
*/
- if (time_pps_create(fd, &up->handle) < 0) {
- up->handle = 0;
- msyslog(LOG_ERR,
- "refclock_nmea: time_pps_create failed: %m");
- return (1);
- }
+ msyslog(LOG_ERR, "refclock_nmea: found GPS source \"%s\"", device);
+ (void) sprintf(device, DEVICEPPS, unit);
+ fd = open(device, O_RDWR);
+ if (fd < 0) { /* no /dev/gpspps0 */
+ goto try_main_device; /* Try /dev/gps device for PPS */
+ } else { /* /dev/gpspps0 exists */
+ msyslog(LOG_ERR, "refclock_nmea: try \"%s\" for PPS", device);
+ if (time_pps_create(fd, &up->handle) < 0)
+ goto try_main_device; /* Try /dev/gps for PPS */
+ else goto found_source; /* PPS on /dev/gpspps0 */
+ }
+
+try_main_device:
+ (void) sprintf(device, DEVICE, unit);
+ msyslog(LOG_ERR, "refclock_nmea: try GPS device \"%s\" for PPS", device);
+ if (time_pps_create(pp->io.fd, &up->handle) < 0)
+ goto pps_error;
+found_source:
+ msyslog(LOG_INFO, "refclock_nmea: found PPS source \"%s\"", device);
return(nmea_ppsapi(peer, 0, 0));
+
+pps_error:
+ /* No luck, no PPS unit available! */
+ up->handle = -1;
+ msyslog(LOG_ERR, "refclock_nmea: no PPS devices found at " DEVICE " nor " DEVICEPPS ": %m", unit, unit);
+ return (1);
#else
return (1);
#endif /* HAVE_PPSAPI */
@@ -257,8 +278,7 @@
pp = peer->procptr;
up = (struct nmeaunit *)pp->unitptr;
#ifdef HAVE_PPSAPI
- if (up->handle != 0)
- time_pps_destroy(up->handle);
+ time_pps_destroy(up->handle);
#endif /* HAVE_PPSAPI */
io_closeclock(&pp->io);
free(up);
@@ -366,7 +386,7 @@
/*
* Convert the timespec nanoseconds field to ntp l_fp units.
*/
- if (up->handle == 0)
+ if (up->handle == -1)
return (0);
timeout.tv_sec = 0;
timeout.tv_nsec = 0;
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