summaryrefslogtreecommitdiffstats
path: root/refclock_phc.c
blob: e0e206edeed3543ec702f29b1804128b52a0a302 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
/*
  chronyd/chronyc - Programs for keeping computer clocks accurate.

 **********************************************************************
 * Copyright (C) Miroslav Lichvar  2013, 2017
 * 
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 * 
 **********************************************************************

  =======================================================================

  PTP hardware clock (PHC) refclock driver.

  */

#include "config.h"

#include "refclock.h"

#ifdef FEAT_PHC

#include "sysincl.h"

#include "refclock.h"
#include "hwclock.h"
#include "local.h"
#include "logging.h"
#include "memory.h"
#include "util.h"
#include "sched.h"
#include "sys_linux.h"

struct phc_instance {
  int fd;
  int mode;
  int nocrossts;
  int extpps;
  int pin;
  int channel;
  HCL_Instance clock;
};

static void read_ext_pulse(int sockfd, int event, void *anything);

static int phc_initialise(RCL_Instance instance)
{
  const char *options[] = {"nocrossts", "extpps", "pin", "channel", "clear", NULL};
  struct phc_instance *phc;
  int phc_fd, rising_edge;
  char *path, *s;

  RCL_CheckDriverOptions(instance, options);

  path = RCL_GetDriverParameter(instance);
 
  phc_fd = SYS_Linux_OpenPHC(path, 0);
  if (phc_fd < 0)
    LOG_FATAL("Could not open PHC");

  phc = MallocNew(struct phc_instance);
  phc->fd = phc_fd;
  phc->mode = 0;
  phc->nocrossts = RCL_GetDriverOption(instance, "nocrossts") ? 1 : 0;
  phc->extpps = RCL_GetDriverOption(instance, "extpps") ? 1 : 0;

  phc->clock = HCL_CreateInstance(0, 16, UTI_Log2ToDouble(RCL_GetDriverPoll(instance)),
                                  RCL_GetPrecision(instance));

  if (phc->extpps) {
    s = RCL_GetDriverOption(instance, "pin");
    phc->pin = s ? atoi(s) : 0;
    s = RCL_GetDriverOption(instance, "channel");
    phc->channel = s ? atoi(s) : 0;
    rising_edge = RCL_GetDriverOption(instance, "clear") ? 0 : 1;

    if (!SYS_Linux_SetPHCExtTimestamping(phc->fd, phc->pin, phc->channel,
                                         rising_edge, !rising_edge, 1))
      LOG_FATAL("Could not enable external PHC timestamping");

    SCH_AddFileHandler(phc->fd, SCH_FILE_INPUT, read_ext_pulse, instance);
  } else {
    phc->pin = phc->channel = 0;
  }

  RCL_SetDriverData(instance, phc);
  return 1;
}

static void phc_finalise(RCL_Instance instance)
{
  struct phc_instance *phc;

  phc = (struct phc_instance *)RCL_GetDriverData(instance);

  if (phc->extpps) {
    SCH_RemoveFileHandler(phc->fd);
    SYS_Linux_SetPHCExtTimestamping(phc->fd, phc->pin, phc->channel, 0, 0, 0);
  }

  HCL_DestroyInstance(phc->clock);
  close(phc->fd);
  Free(phc);
}

static void read_ext_pulse(int fd, int event, void *anything)
{
  RCL_Instance instance;
  struct phc_instance *phc;
  struct timespec phc_ts, local_ts;
  double local_err;
  int channel;

  instance = anything;
  phc = RCL_GetDriverData(instance);

  if (!SYS_Linux_ReadPHCExtTimestamp(phc->fd, &phc_ts, &channel))
    return;

  if (channel != phc->channel) {
    DEBUG_LOG("Unexpected extts channel %d\n", channel);
    return;
  }

  if (!HCL_CookTime(phc->clock, &phc_ts, &local_ts, &local_err))
    return;

  RCL_AddCookedPulse(instance, &local_ts, 1.0e-9 * local_ts.tv_nsec, local_err,
                     UTI_DiffTimespecsToDouble(&phc_ts, &local_ts));
}

#define PHC_READINGS 25

static int phc_poll(RCL_Instance instance)
{
  struct timespec phc_ts, sys_ts, local_ts, readings[PHC_READINGS][3];
  struct phc_instance *phc;
  double phc_err, local_err;
  int n_readings;

  phc = (struct phc_instance *)RCL_GetDriverData(instance);

  n_readings = SYS_Linux_GetPHCReadings(phc->fd, phc->nocrossts, &phc->mode,
                                        PHC_READINGS, readings);
  if (n_readings < 1)
    return 0;

  if (!HCL_ProcessReadings(phc->clock, n_readings, readings, &phc_ts, &sys_ts, &phc_err))
    return 0;

  LCL_CookTime(&sys_ts, &local_ts, &local_err);
  HCL_AccumulateSample(phc->clock, &phc_ts, &local_ts, phc_err + local_err);

  if (phc->extpps)
    return 0;

  DEBUG_LOG("PHC offset: %+.9f err: %.9f",
            UTI_DiffTimespecsToDouble(&phc_ts, &sys_ts), phc_err);

  return RCL_AddSample(instance, &sys_ts, &phc_ts, LEAP_Normal);
}

RefclockDriver RCL_PHC_driver = {
  phc_initialise,
  phc_finalise,
  phc_poll
};

#else

RefclockDriver RCL_PHC_driver = { NULL, NULL, NULL };

#endif