Add PPS API refclock driver

refclock_pps.c

@@ -0,0 +1,167 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2009
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  PPSAPI refclock driver.
+
+  */
+
+#include "refclock.h"
+
+#if HAVE_PPSAPI
+
+#include <timepps.h>
+
+#include "logging.h"
+#include "memory.h"
+#include "util.h"
+
+struct pps_instance {
+  pps_handle_t handle;
+  unsigned long last_seq;
+  int edge_clear;
+};
+
+static int pps_initialise(RCL_Instance instance) {
+  pps_handle_t handle;
+  pps_params_t params;
+  struct pps_instance *pps;
+  int fd, edge_clear, mode;
+  char *path, *s;
+
+  path = RCL_GetDriverParameter(instance);
+
+  edge_clear = 0;
+  if ((s = strrchr(path, ':')) != NULL) {
+    *s = '\0';
+    edge_clear = atoi(s + 1);
+  }
+
+  fd = open(path, O_RDWR);
+  if (fd < 0) {
+    LOG_FATAL(LOGF_Refclock, "open() failed on %s", path);
+    return 0;
+  }
+
+  if (time_pps_create(fd, &handle) < 0) {
+    LOG_FATAL(LOGF_Refclock, "time_pps_create() failed on %s", path);
+    return 0;
+  }
+
+  if (time_pps_getcap(handle, &mode) < 0) {
+    LOG_FATAL(LOGF_Refclock, "time_pps_getcap() failed on %s", path);
+    return 0;
+  }
+
+  if (time_pps_getparams(handle, &params) < 0) {
+    LOG_FATAL(LOGF_Refclock, "time_pps_getparams() failed on %s", path);
+    return 0;
+  }
+
+  if (!edge_clear) {
+    if (!(mode & PPS_CAPTUREASSERT)) {
+      LOG_FATAL(LOGF_Refclock, "CAPTUREASSERT not supported on %s", path);
+      return 0;
+    }
+    params.mode |= PPS_CAPTUREASSERT;
+    params.mode &= ~PPS_CAPTURECLEAR;
+  } else {
+    if (!(mode & PPS_CAPTURECLEAR)) {
+      LOG_FATAL(LOGF_Refclock, "CAPTURECLEAR not supported on %s", path);
+      return 0;
+    }
+    params.mode |= PPS_CAPTURECLEAR;
+    params.mode &= ~PPS_CAPTUREASSERT;
+  }
+
+  if (time_pps_setparams(handle, &params) < 0) {
+    LOG_FATAL(LOGF_Refclock, "time_pps_setparams() failed on %s", path);
+    return 0;
+  }
+
+  pps = MallocNew(struct pps_instance);
+  pps->handle = handle;
+  pps->last_seq = 0;
+  pps->edge_clear = edge_clear;
+
+  RCL_SetDriverData(instance, pps);
+  return 1;
+}
+
+static void pps_finalise(RCL_Instance instance)
+{
+  struct pps_instance *pps; 
+
+  pps = (struct pps_instance *)RCL_GetDriverData(instance);
+  time_pps_destroy(pps->handle);
+  Free(pps);
+}
+
+static int pps_poll(RCL_Instance instance)
+{
+  struct pps_instance *pps; 
+  struct timespec ts;
+  struct timeval tv;
+  pps_info_t pps_info;
+  unsigned long seq;
+
+  pps = (struct pps_instance *)RCL_GetDriverData(instance);
+
+  ts.tv_sec = 0;
+  ts.tv_nsec = 0;
+
+  if (time_pps_fetch(pps->handle, PPS_TSFMT_TSPEC, &pps_info, &ts) < 0) {
+#if 0
+    LOG(LOGS_INFO, LOGF_Refclock, "time_pps_fetch error");
+#endif
+    return 0;
+  }
+
+  if (!pps->edge_clear) {
+    seq = pps_info.assert_sequence;
+    ts = pps_info.assert_timestamp;
+  } else {
+    seq = pps_info.clear_sequence;
+    ts = pps_info.clear_timestamp;
+  }
+
+  if (seq == pps->last_seq || (ts.tv_sec == 0 && ts.tv_nsec == 0)) { 
+    return 0;
+  }
+
+  tv.tv_sec = ts.tv_sec;
+  tv.tv_usec = ts.tv_nsec / 1000;
+
+  return RCL_AddPulse(instance, &tv, ts.tv_nsec / 1e9);
+}
+
+RefclockDriver RCL_PPS_driver = {
+  pps_initialise,
+  pps_finalise,
+  pps_poll
+};
+
+#else
+
+RefclockDriver RCL_PPS_driver = { NULL, NULL, NULL };
+
+#endif