1/*-
2 * Copyright (c) 1988 University of Utah.
3 * Copyright (c) 1982, 1990, 1993
4 *	The Regents of the University of California.
5 * Copyright (c) 2011 The FreeBSD Foundation
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * the Systems Programming Group of the University of Utah Computer
10 * Science Department.
11 *
12 * Portions of this software were developed by Julien Ridoux at the University
13 * of Melbourne under sponsorship from the FreeBSD Foundation.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * 1. Redistributions of source code must retain the above copyright
19 *    notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 *    notice, this list of conditions and the following disclaimer in the
22 *    documentation and/or other materials provided with the distribution.
23 * 4. Neither the name of the University nor the names of its contributors
24 *    may be used to endorse or promote products derived from this software
25 *    without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 *	from: Utah $Hdr: clock.c 1.18 91/01/21$
40 *	from: @(#)clock.c	8.2 (Berkeley) 1/12/94
41 *	from: NetBSD: clock_subr.c,v 1.6 2001/07/07 17:04:02 thorpej Exp
42 *	and
43 *	from: src/sys/i386/isa/clock.c,v 1.176 2001/09/04
44 */
45
46/*
47 * Helpers for time-of-day clocks. This is useful for architectures that need
48 * support multiple models of such clocks, and generally serves to make the
49 * code more machine-independent.
50 * If the clock in question can also be used as a time counter, the driver
51 * needs to initiate this.
52 * This code is not yet used by all architectures.
53 */
54
55#include <sys/cdefs.h>
56__FBSDID("$FreeBSD$");
57
58#include "opt_ffclock.h"
59
60#include <sys/param.h>
61#include <sys/systm.h>
62#include <sys/kernel.h>
63#include <sys/bus.h>
64#include <sys/clock.h>
65#include <sys/sysctl.h>
66#ifdef FFCLOCK
67#include <sys/timeffc.h>
68#endif
69#include <sys/timetc.h>
70
71#include "clock_if.h"
72
73static device_t clock_dev = NULL;
74static long clock_res;
75static struct timespec clock_adj;
76
77/* XXX: should be kern. now, it's no longer machdep.  */
78static int disable_rtc_set;
79SYSCTL_INT(_machdep, OID_AUTO, disable_rtc_set, CTLFLAG_RW, &disable_rtc_set,
80    0, "Disallow adjusting time-of-day clock");
81
82void
83clock_register(device_t dev, long res)	/* res has units of microseconds */
84{
85
86	if (clock_dev != NULL) {
87		if (clock_res > res) {
88			if (bootverbose)
89				device_printf(dev, "not installed as "
90				    "time-of-day clock: clock %s has higher "
91				    "resolution\n", device_get_name(clock_dev));
92			return;
93		}
94		if (bootverbose)
95			device_printf(clock_dev, "removed as "
96			    "time-of-day clock: clock %s has higher "
97			    "resolution\n", device_get_name(dev));
98	}
99	clock_dev = dev;
100	clock_res = res;
101	clock_adj.tv_sec = res / 2 / 1000000;
102	clock_adj.tv_nsec = res / 2 % 1000000 * 1000;
103	if (bootverbose)
104		device_printf(dev, "registered as a time-of-day clock "
105		    "(resolution %ldus, adjustment %jd.%09jds)\n", res,
106		    (intmax_t)clock_adj.tv_sec, (intmax_t)clock_adj.tv_nsec);
107}
108
109/*
110 * inittodr and settodr derived from the i386 versions written
111 * by Christoph Robitschko <chmr@edvz.tu-graz.ac.at>,  reintroduced and
112 * updated by Chris Stenton <chris@gnome.co.uk> 8/10/94
113 */
114
115/*
116 * Initialize the time of day register, based on the time base which is, e.g.
117 * from a filesystem.
118 */
119void
120inittodr(time_t base)
121{
122	struct timespec ts;
123	int error;
124
125	if (clock_dev == NULL) {
126		printf("warning: no time-of-day clock registered, system time "
127		    "will not be set accurately\n");
128		goto wrong_time;
129	}
130	/* XXX: We should poll all registered RTCs in case of failure */
131	error = CLOCK_GETTIME(clock_dev, &ts);
132	if (error != 0 && error != EINVAL) {
133		printf("warning: clock_gettime failed (%d), the system time "
134		    "will not be set accurately\n", error);
135		goto wrong_time;
136	}
137	if (error == EINVAL || ts.tv_sec < 0) {
138		printf("Invalid time in real time clock.\n"
139		    "Check and reset the date immediately!\n");
140		goto wrong_time;
141	}
142
143	ts.tv_sec += utc_offset();
144	timespecadd(&ts, &clock_adj);
145	tc_setclock(&ts);
146#ifdef FFCLOCK
147	ffclock_reset_clock(&ts);
148#endif
149	return;
150
151wrong_time:
152	if (base > 0) {
153		ts.tv_sec = base;
154		ts.tv_nsec = 0;
155		tc_setclock(&ts);
156	}
157}
158
159/*
160 * Write system time back to RTC
161 */
162void
163resettodr(void)
164{
165	struct timespec ts;
166	int error;
167
168	if (disable_rtc_set || clock_dev == NULL)
169		return;
170
171	getnanotime(&ts);
172	timespecadd(&ts, &clock_adj);
173	ts.tv_sec -= utc_offset();
174	/* XXX: We should really set all registered RTCs */
175	if ((error = CLOCK_SETTIME(clock_dev, &ts)) != 0)
176		printf("warning: clock_settime failed (%d), time-of-day clock "
177		    "not adjusted to system time\n", error);
178}
179