timetrim.c revision 290001 
1#if defined(sgi) || defined(_UNICOSMP)
2/*
3 * timetrim.c
4 *
5 * "timetrim" allows setting and adjustment of the system clock frequency
6 * trim parameter on Silicon Graphics machines.  The trim value native
7 * units are nanoseconds per second (10**-9), so a trim value of 1 makes
8 * the system clock step ahead 1 nanosecond more per second than a value
9 * of zero.  Xntpd currently uses units of 2**-20 secs for its frequency
10 * offset (drift) values; to convert to a timetrim value, multiply by
11 * 1E9 / 2**20 (about 954).
12 *
13 * "timetrim" with no arguments just prints out the current kernel value.
14 * With a numeric argument, the kernel value is set to the supplied value.
15 * The "-i" flag causes the supplied value to be added to the kernel value.
16 * The "-n" option causes all input and output to be in xntpd units rather
17 * than timetrim native units.
18 *
19 * Note that there is a limit of +-3000000 (0.3%) on the timetrim value
20 * which is (silently?) enforced by the kernel.
21 *
22 */
23
24#ifdef HAVE_CONFIG_H
25#include <config.h>
26#endif
27
28#include <stdio.h>
29#include <ctype.h>
30#include <stdlib.h>
31#ifdef HAVE_SYS_SYSSGI_H
32# include <sys/syssgi.h>
33#endif
34#ifdef HAVE_SYS_SYSTUNE_H
35# include <sys/systune.h>
36#endif
37
38#define abs(X) (((X) < 0) ? -(X) : (X))
39#define USAGE "usage: timetrim [-n] [[-i] value]\n"
40#define SGITONTP(X) ((double)(X) * 1048576.0/1.0e9)
41#define NTPTOSGI(X) ((long)((X) * 1.0e9/1048576.0))
42
43int
44main(
45	int argc,
46	char *argv[]
47	)
48{
49	char *rem;
50	int incremental = 0, ntpunits = 0;
51	long timetrim;
52	double value;
53
54	while (--argc && **++argv == '-' && isalpha((int)argv[0][1])) {
55		switch (argv[0][1]) {
56		    case 'i':
57			incremental++;
58			break;
59		    case 'n':
60			ntpunits++;
61			break;
62		    default:
63			fprintf(stderr, USAGE);
64			exit(1);
65		}
66	}
67
68#ifdef HAVE_SYS_SYSSGI_H
69	if (syssgi(SGI_GETTIMETRIM, &timetrim) < 0) {
70		perror("syssgi");
71		exit(2);
72	}
73#endif
74#ifdef HAVE_SYS_SYSTUNE_H
75	if (systune(SYSTUNE_GET, "timetrim", &timetrim) < 0) {
76		perror("systune");
77		exit(2);
78	}
79#endif
80
81	if (argc == 0) {
82		if (ntpunits)
83		    fprintf(stdout, "%0.5f\n", SGITONTP(timetrim));
84		else
85		    fprintf(stdout, "%ld\n", timetrim);
86	} else if (argc != 1) {
87		fprintf(stderr, USAGE);
88		exit(1);
89	} else {
90		value = strtod(argv[0], &rem);
91		if (*rem != '\0') {
92			fprintf(stderr, USAGE);
93			exit(1);
94		}
95		if (ntpunits)
96		    value = NTPTOSGI(value);
97		if (incremental)
98		    timetrim += value;
99		else
100		    timetrim = value;
101#ifdef HAVE_SYS_SYSSGI_H
102		if (syssgi(SGI_SETTIMETRIM, timetrim) < 0) {
103			perror("syssgi");
104			exit(2);
105		}
106#endif
107#ifdef HAVE_SYS_SYSTUNE_H
108		if (systune(SYSTUNE_SET, "timer", "timetrim", &timetrim) < 0) {
109			perror("systune");
110			exit(2);
111		}
112#endif
113	}
114	return 0;
115}
116#endif
117