1/*	$NetBSD: clockvar.h,v 1.1 2024/01/02 07:41:00 thorpej Exp $	*/
2
3/*-
4 * Copyright (c) 1996, 2002, 2023 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#ifndef _VIRT68K_CLOCKVAR_H_
33#define _VIRT68K_CLOCKVAR_H_
34
35#include <sys/evcnt.h>
36#include <dev/clock_subr.h>
37
38extern	int clock_statvar;
39extern	int clock_statmin;
40struct clockframe;
41
42#define	CLOCK_NONE		-1
43#define	CLOCK_HARDCLOCK		0
44#define	CLOCK_STATCLOCK		1
45#define	NCLOCKS			2
46
47struct clock_attach_args {
48	void			(*ca_initfunc)(void *, unsigned int,
49				    struct evcnt *ev,
50				    void (*func)(struct clockframe *));
51	void			*ca_arg;
52	struct evcnt		*ca_parent_evcnt;
53	int			ca_which;
54};
55
56const char *clock_name(int);
57void	clock_attach(device_t, struct clock_attach_args *,
58	    void (*)(device_t, unsigned int));
59
60extern void *clock_devices[NCLOCKS];
61
62/*
63 * Macro to compute a new randomized interval.  The intervals are
64 * uniformly distributed on [statint - statvar / 2, statint + statvar / 2],
65 * and therefore have mean statint, giving a stathz frequency clock.
66 *
67 * This is gratuitously stolen from sparc/sparc/clock.c
68 */
69#define CLOCK_NEWINT(statvar, statmin)	({				\
70		u_long r, var = (statvar);				\
71		do { r = random() & (var - 1); } while (r == 0);	\
72		(statmin + r);						\
73	})
74
75/*
76 * Sun chose the year `68' as their base count, so that
77 * cl_year==0 means 1968.
78 */
79#define YEAR0   1968
80
81#endif /* _VIRT68K_CLOCKVAR_H_ */
82