File: rtc.c

package info (click to toggle)
chrony 1.14-7
  • links: PTS
  • area: main
  • in suites: woody
  • size: 1,480 kB
  • ctags: 2,091
  • sloc: ansic: 15,266; sh: 194; makefile: 113
file content (209 lines) | stat: -rw-r--r-- 4,391 bytes parent folder | download
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
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
/*
  $Header: /cvs/src/chrony/rtc.c,v 1.10 1999/04/19 20:27:29 richard Exp $

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

  chronyd/chronyc - Programs for keeping computer clocks accurate.

  Copyright (C) 1997-1999 Richard P. Curnow
  All rights reserved.

  For conditions of use, refer to the file LICENCE.

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

  */

#include "sysincl.h"

#include "rtc.h"
#include "logging.h"
#include "conf.h"

#if defined LINUX
#include "rtc_linux.h"
#endif /* defined LINUX */

/* ================================================== */

static int driver_initialised = 0;

static struct {
  int  (*init)(void);
  void (*fini)(void);
  void (*time_pre_init)(void);
  void (*time_init)(void (*after_hook)(void*), void *anything);
  void (*start_measurements)(void);
  int  (*write_parameters)(void);
  int  (*get_report)(RPT_RTC_Report *report);
  int  (*trim)(void);
  void (*cycle_logfile)(void);
} driver =
{
#if defined LINUX
  RTC_Linux_Initialise,
  RTC_Linux_Finalise,
  RTC_Linux_TimePreInit,
  RTC_Linux_TimeInit,
  RTC_Linux_StartMeasurements,
  RTC_Linux_WriteParameters,
  RTC_Linux_GetReport,
  RTC_Linux_Trim,
  RTC_Linux_CycleLogFile
#else
  NULL,
  NULL,
  NULL,
  NULL,
  NULL,
  NULL,
  NULL,
  NULL,
  NULL
#endif 
};
     
/* ================================================== */

void
RTC_Initialise(void)
{
  char *file_name;
  int ok;

  /* This is how we tell whether the user wants to load the RTC
     driver, if he is on a machine where it is an option. */
  file_name = CNF_GetRtcFile();

  if (file_name) {
    if (driver.init) {
      if ((driver.init)()) {
        ok = 1;
      } else {
        ok = 0;
      }
    } else {
      ok = 0;
    }

    if (ok) {
      driver_initialised = 1;
    } else {
      driver_initialised = 0;
      LOG(LOGS_ERR, LOGF_Rtc, "Real time clock not supported on this operating system\n");
    }

  } else {
    driver_initialised = 0;
  }

  return;

}

/* ================================================== */

void
RTC_Finalise(void)
{
  if (driver.fini) {
    (driver.fini)();
  }
}

/* ================================================== */
/* Start the processing to get a single measurement from the real time
   clock, and use it to trim the system time, based on knowing the
   drift rate of the RTC and the error the last time we set it.  The
   TimePreInit routine has already run, so we can be sure that the
   trim required is not *too* large.

   We are called with a hook to a function to be called after the
   initialisation is complete.  We also call this if we cannot do the
   initialisation. */

void
RTC_TimeInit(void (*after_hook)(void *), void *anything)
{
  if (driver_initialised) {
    (driver.time_init)(after_hook, anything);
  } else {
    LOG(LOGS_ERR, LOGF_Rtc, "Can't initialise from real time clock, driver not loaded\n");
    (after_hook)(anything);
  }
}

/* ================================================== */
/* Do an initial read of the RTC and set the system time to it.  This
   is analogous to what /sbin/clock -s -u would do on Linux. */

void
RTC_TimePreInit(void)
{
  if (driver.time_pre_init) {
    (driver.time_pre_init)();
  }
}

/* ================================================== */
/* Start the RTC measurement process */

void
RTC_StartMeasurements(void)
{
  if (driver_initialised) {
    (driver.start_measurements)();
  }
  /* Benign if driver not present */
}

/* ================================================== */
/* Write RTC information out to RTC file.  Return 0 for success, 1 if
   RTC driver not running, or 2 if the file cannot be written. */

int
RTC_WriteParameters(void)
{
  if (driver_initialised) {
    return (driver.write_parameters)();
  } else {
    return RTC_ST_NODRV;
  }
}

/* ================================================== */

int
RTC_GetReport(RPT_RTC_Report *report)
{
  if (driver_initialised) {
    return (driver.get_report)(report);
  } else {
    return 0;
  }
}

/* ================================================== */

int
RTC_Trim(void)
{
  if (driver_initialised) {
    return (driver.trim)();
  } else {
    return 0;
  }
}

/* ================================================== */

void
RTC_CycleLogFile(void)
{
  if (driver_initialised) {
    (driver.cycle_logfile)();
  }
}

/* ================================================== */