lora: fix gps time stamping and synchronization, add patch for PKF deduplication to be incorporated into recipe later

1 files changed, 192 insertions, 27 deletions

diff --git a/recipes-connectivity/lora/lora-gateway/lora-gateway-gpsd.patch b/recipes-connectivity/lora/lora-gateway/lora-gateway-gpsd.patch
index 471cd82..08d566c 100644
--- a/recipes-connectivity/lora/lora-gateway/lora-gateway-gpsd.patch
+++ b/recipes-connectivity/lora/lora-gateway/lora-gateway-gpsd.patch
@@ -73,10 +73,18 @@ index 6dbd30b..59b2d37 100644
  /**
  @brief Parse messages coming from the GPS system (or other GNSS)
 diff --git a/libloragw/src/loragw_gps.c b/libloragw/src/loragw_gps.c
-index c0e0ded..d3d1ca1 100644
+index c0e0ded..f4774be 100644
 --- a/libloragw/src/loragw_gps.c
 +++ b/libloragw/src/loragw_gps.c
-@@ -251,109 +251,22 @@ int str_chop(char *s, int buff_size, char separator, int *idx_ary, int max_idx)
+@@ -84,6 +84,7 @@ static double gps_mlo = 0.0; /* minutes of longitude */
+ static char gps_olo = 0; /* orientation (E-W) of longitude */
+ static short gps_alt = 0; /* altitude */
+ static bool gps_pos_ok = false;
++static bool gps_lock_ok = false;
+ 
+ static char gps_mod = 'N'; /* GPS mode (N no fix, A autonomous, D differential) */
+ static short gps_sat = 0; /* number of satellites used for fix */
+@@ -251,109 +252,22 @@ int str_chop(char *s, int buff_size, char separator, int *idx_ary, int max_idx)
  /* -------------------------------------------------------------------------- */
  /* --- PUBLIC FUNCTIONS DEFINITION ------------------------------------------ */
  
@@ -91,17 +99,27 @@ index c0e0ded..d3d1ca1 100644
 -                    0x01, 0x20, 0x00, 0x01, 0x01, 0x00, 0x00, 0x00, /* Enable NAV-TIMEGPS output on serial */
 -                    0x32, 0x94 }; /* Checksum */
 -    ssize_t num_written;
--
++int lgw_gps_enable(struct gps_data_t *gpsdata, struct fixsource_t *source) {
+ 
 -    /* check input parameters */
 -    CHECK_NULL(tty_path);
 -    CHECK_NULL(fd_ptr);
--
++    unsigned int flags;
++    fd_set fds;
++    flags = WATCH_ENABLE;
++    flags |= WATCH_RAW;
++    flags |= WATCH_NMEA;
++    gpsd_source_spec(NULL, source);
+ 
 -    /* open TTY device */
 -    gps_tty_dev = open(tty_path, O_RDWR | O_NOCTTY);
 -    if (gps_tty_dev <= 0) {
 -        DEBUG_MSG("ERROR: TTY PORT FAIL TO OPEN, CHECK PATH AND ACCESS RIGHTS\n");
--        return LGW_GPS_ERROR;
--    }
++    if (gps_open(source->server, source->port, gpsdata) != 0) {
++        DEBUG_MSG("gpspipe: could not connect to gpsd %s:%s, %s(%d)\n",
++              source->server, source->port, gps_errstr(errno), errno);
+         return LGW_GPS_ERROR;
+     }
 -    *fd_ptr = gps_tty_dev;
 -
 -    /* manage the different GPS modules families */
@@ -115,7 +133,7 @@ index c0e0ded..d3d1ca1 100644
 -        /* see lgw_parse_ubx() function for details */
 -        DEBUG_MSG("WARNING: this version of GPS module may not be supported\n");
 -    }
--
+ 
 -    /* manage the target bitrate */
 -    if (target_brate != 0) {
 -        DEBUG_MSG("WARNING: target_brate parameter ignored for now\n"); // TODO
@@ -173,22 +191,10 @@ index c0e0ded..d3d1ca1 100644
 -    i = tcsetattr(gps_tty_dev, TCSANOW, &ttyopt);
 -    if (i != 0){
 -        DEBUG_MSG("ERROR: IMPOSSIBLE TO UPDATE TTY PORT CONFIGURATION\n");
-+int lgw_gps_enable(struct gps_data_t *gpsdata, struct fixsource_t *source) {
-+
-+    unsigned int flags;
-+    fd_set fds;
-+    flags = WATCH_ENABLE;
-+    flags |= WATCH_RAW;
-+    flags |= WATCH_NMEA;
-+    gpsd_source_spec(NULL, source);
-+
-+    if (gps_open(source->server, source->port, gpsdata) != 0) {
-+        DEBUG_MSG("gpspipe: could not connect to gpsd %s:%s, %s(%d)\n",
-+              source->server, source->port, gps_errstr(errno), errno);
-         return LGW_GPS_ERROR;
-     }
+-        return LGW_GPS_ERROR;
+-    }
 -    tcflush(gps_tty_dev, TCIOFLUSH);
- 
+-
 -    /* Send UBX CFG NAV-TIMEGPS message to tell GPS module to output native GPS time */
 -    /* This is a binary message, serial port has to be properly configured to handle this */
 -    num_written = write (gps_tty_dev, ubx_cmd_timegps, UBX_MSG_NAVTIMEGPS_LEN);
@@ -199,7 +205,7 @@ index c0e0ded..d3d1ca1 100644
  
      /* get timezone info */
      tzset();
-@@ -368,20 +281,13 @@ int lgw_gps_enable(char *tty_path, char *gps_family, speed_t target_brate, int *
+@@ -368,20 +282,13 @@ int lgw_gps_enable(char *tty_path, char *gps_family, speed_t target_brate, int *
  
  /* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
  
@@ -225,7 +231,44 @@ index c0e0ded..d3d1ca1 100644
          return LGW_GPS_ERROR;
      }
  
-@@ -526,7 +432,7 @@ enum gps_msg lgw_parse_nmea(const char *serial_buff, int buff_size) {
+@@ -457,7 +364,8 @@ enum gps_msg lgw_parse_ubx(const char *serial_buff, size_t buff_size, size_t *ms
+                         gps_week =  (uint8_t)serial_buff[14];
+                         gps_week |= (uint8_t)serial_buff[15] << 8; /* GPS week number */
+ 
+-                        gps_time_ok = true;
++
++
+ #if 0
+                         /* For debug */
+                         {
+@@ -472,11 +380,24 @@ enum gps_msg lgw_parse_ubx(const char *serial_buff, size_t buff_size, size_t *ms
+                             printf("  GPS time = %02d:%02d:%02d\n", ubx_gps_hou, ubx_gps_min, ubx_gps_sec);
+                         }
+ #endif
+-                    } else { /* valid */
++                        if (gps_lock_ok)
++                           gps_time_ok = true;
++
++                        return UBX_NAV_TIMEGPS;
++                    } else {
+                         gps_time_ok = false;
++                        return INVALID;
++		    }
++                } else if ((serial_buff[2] == 0x01) && (serial_buff[3] == 0x04)) {
++                    if (serial_buff[10] == 0x0F && serial_buff[11] == 0x27
++                       && serial_buff[10] == 0x0F && serial_buff[11] == 0x27
++                       && serial_buff[10] == 0x0F && serial_buff[11] == 0x27
++                       && serial_buff[10] == 0x0F && serial_buff[11] == 0x27) {
++			gps_time_ok = false;
++			gps_lock_ok = false;
+                     }
+ 
+-                    return UBX_NAV_TIMEGPS;
++                    return UBX_NAV_TIMEUTC;
+                 } else if ((serial_buff[2] == 0x05) && (serial_buff[3] == 0x00)) {
+                     DEBUG_MSG("NOTE: UBX ACK-NAK received\n");
+                     return IGNORED;
+@@ -526,7 +447,7 @@ enum gps_msg lgw_parse_nmea(const char *serial_buff, int buff_size) {
      } else if (!validate_nmea_checksum(serial_buff, buff_size)) {
          DEBUG_MSG("Warning: invalid NMEA sentence (bad checksum)\n");
          return INVALID;
@@ -234,7 +277,7 @@ index c0e0ded..d3d1ca1 100644
          /*
          NMEA sentence format: $xxRMC,time,status,lat,NS,long,EW,spd,cog,date,mv,mvEW,posMode*cs<CR><LF>
          Valid fix: $GPRMC,083559.34,A,4717.11437,N,00833.91522,E,0.004,77.52,091202,,,A*00
-@@ -535,19 +441,19 @@ enum gps_msg lgw_parse_nmea(const char *serial_buff, int buff_size) {
+@@ -535,33 +456,32 @@ enum gps_msg lgw_parse_nmea(const char *serial_buff, int buff_size) {
          memcpy(parser_buf, serial_buff, buff_size);
          parser_buf[buff_size] = '\0';
          nb_fields = str_chop(parser_buf, buff_size, ',', str_index, ARRAY_SIZE(str_index));
@@ -255,9 +298,17 @@ index c0e0ded..d3d1ca1 100644
 -        if ((i == 4) && (j == 3)) {
 +        if ((i == 3) && (j == 3)) {
              if ((gps_mod == 'A') || (gps_mod == 'D')) {
-                 gps_time_ok = true;
+-                gps_time_ok = true;
++                gps_lock_ok = true;
                  DEBUG_MSG("Note: Valid RMC sentence, GPS locked, date: 20%02d-%02d-%02dT%02d:%02d:%06.3fZ\n", gps_yea, gps_mon, gps_day, gps_hou, gps_min, gps_fra + (float)gps_sec);
-@@ -561,7 +467,7 @@ enum gps_msg lgw_parse_nmea(const char *serial_buff, int buff_size) {
+             } else {
+-                gps_time_ok = false;
++                gps_lock_ok = false;
+                 DEBUG_MSG("Note: Valid RMC sentence, no satellite fix, estimated date: 20%02d-%02d-%02dT%02d:%02d:%06.3fZ\n", gps_yea, gps_mon, gps_day, gps_hou, gps_min, gps_fra + (float)gps_sec);
+             }
+         } else {
+             /* could not get a valid hour AND date */
+-            gps_time_ok = false;
              DEBUG_MSG("Note: Valid RMC sentence, mode %c, no date\n", gps_mod);
          }
          return NMEA_RMC;
@@ -266,6 +317,120 @@ index c0e0ded..d3d1ca1 100644
          /*
          NMEA sentence format: $xxGGA,time,lat,NS,long,EW,quality,numSV,HDOP,alt,M,sep,M,diffAge,diffStation*cs<CR><LF>
          Valid fix: $GPGGA,092725.00,4717.11399,N,00833.91590,E,1,08,1.01,499.6,M,48.0,M,,*5B
+@@ -587,6 +507,8 @@ enum gps_msg lgw_parse_nmea(const char *serial_buff, int buff_size) {
+         } else {
+             /* could not get a valid latitude, longitude AND altitude */
+             gps_pos_ok = false;
++            gps_time_ok = false;
++            gps_lock_ok = false;
+             DEBUG_MSG("Note: Valid GGA sentence, %d sat, no coordinates\n", gps_sat);
+         }
+         return NMEA_GGA;
+@@ -662,72 +580,60 @@ int lgw_gps_get(struct timespec *utc, struct timespec *gps_time, struct coord_s
+ /* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+ 
+ int lgw_gps_sync(struct tref *ref, uint32_t count_us, struct timespec utc, struct timespec gps_time) {
++    bool update = false;
+     double cnt_diff; /* internal concentrator time difference (in seconds) */
+     double utc_diff; /* UTC time difference (in seconds) */
+-    double slope; /* time slope between new reference and old reference (for sanity check) */
+-
+-    bool aber_n0; /* is the update value for synchronization aberrant or not ? */
+-    static bool aber_min1 = false; /* keep track of whether value at sync N-1 was aberrant or not  */
+-    static bool aber_min2 = false; /* keep track of whether value at sync N-2 was aberrant or not  */
++    double slope = 1.0; /* time slope between new reference and old reference (for sanity check) */
++    static bool calibrating = true;
+ 
+     CHECK_NULL(ref);
+ 
+     /* calculate the slope */
+ 
+-    cnt_diff = (double)(count_us - ref->count_us) / (double)(TS_CPS); /* uncorrected by xtal_err */
+-    utc_diff = (double)(utc.tv_sec - (ref->utc).tv_sec) + (1E-9 * (double)(utc.tv_nsec - (ref->utc).tv_nsec));
++    if (ref->systime != 0) {
++
++        cnt_diff = (double)(count_us - ref->count_us) / (double)(TS_CPS); /* uncorrected by xtal_err */
++        utc_diff = (double)(utc.tv_sec - (ref->utc).tv_sec) + (1E-9 * (double)(utc.tv_nsec - (ref->utc).tv_nsec));
+ 
+-    /* detect aberrant points by measuring if slope limits are exceeded */
+-    if (utc_diff != 0) { // prevent divide by zero
+-        slope = cnt_diff/utc_diff;
+-        if ((slope > PLUS_10PPM) || (slope < MINUS_10PPM)) {
+-            DEBUG_MSG("Warning: correction range exceeded\n");
+-            aber_n0 = true;
++        if (cnt_diff != 0 && utc_diff != 0) { // prevent divide by zero
++            slope = cnt_diff/utc_diff;
+         } else {
+-            aber_n0 = false;
++           slope = 0.0;
++        }
++
++        if (gps_lock_ok && gps_time_ok && cnt_diff > 1.5) {
++           update = true;
++       } 
++
++        update = (slope >= MINUS_10PPM && slope <= PLUS_10PPM);
++
++        if (!calibrating && utc_diff < 10.0) { 
++            return LGW_GPS_ERROR;
+         }
++
++        if (calibrating && !update && utc_diff > 1.5) {
++           update = true;
++        } else if (update) {
++            calibrating = false;
++        }
++
+     } else {
+-        DEBUG_MSG("Warning: aberrant UTC value for synchronization\n");
+-        aber_n0 = true;
++       update = true;
++        slope = 0.0;
+     }
+ 
+-    /* watch if the 3 latest sync point were aberrant or not */
+-    if (aber_n0 == false) {
+-        /* value no aberrant -> sync with smoothed slope */
+-        ref->systime = time(NULL);
++    if (update || calibrating) {
++        ref->systime = time(NULL); 
+         ref->count_us = count_us;
+         ref->utc.tv_sec = utc.tv_sec;
+         ref->utc.tv_nsec = utc.tv_nsec;
+         ref->gps.tv_sec = gps_time.tv_sec;
+         ref->gps.tv_nsec = gps_time.tv_nsec;
+         ref->xtal_err = slope;
+-        aber_min2 = aber_min1;
+-        aber_min1 = aber_n0;
+         return LGW_GPS_SUCCESS;
+-    } else if (aber_n0 && aber_min1 && aber_min2) {
+-        /* 3 successive aberrant values -> sync reset (keep xtal_err) */
+-        ref->systime = time(NULL);
+-        ref->count_us = count_us;
+-        ref->utc.tv_sec = utc.tv_sec;
+-        ref->utc.tv_nsec = utc.tv_nsec;
+-        ref->gps.tv_sec = gps_time.tv_sec;
+-        ref->gps.tv_nsec = gps_time.tv_nsec;
+-        /* reset xtal_err only if the present value is out of range */
+-        if ((ref->xtal_err > PLUS_10PPM) || (ref->xtal_err < MINUS_10PPM)) {
+-            ref->xtal_err = 1.0;
+-        }
+-        DEBUG_MSG("Warning: 3 successive aberrant sync attempts, sync reset\n");
+-        aber_min2 = aber_min1;
+-        aber_min1 = aber_n0;
+-        return LGW_GPS_SUCCESS;
+-    } else {
+-        /* only 1 or 2 successive aberrant values -> ignore and return an error */
+-        aber_min2 = aber_min1;
+-        aber_min1 = aber_n0;
+-        return LGW_GPS_ERROR;
+     }
+ 
+-    return LGW_GPS_SUCCESS;
++    return LGW_GPS_ERROR;
+ }
+ 
+ /* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */ 
 diff --git a/libloragw/tst/test_loragw_gps.c b/libloragw/tst/test_loragw_gps.c
 index a4164a3..e4b1546 100644
 --- a/libloragw/tst/test_loragw_gps.c