xref: /netbsd-src/sys/dev/mvme/clockvar.h (revision 5e4c038a45edbc7d63b7c2daa76e29f88b64a4e3)
1 /*	$NetBSD: clockvar.h,v 1.1 2002/02/12 20:38:41 scw Exp $	*/
2 
3 /*-
4  * Copyright (c) 1996, 2002 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  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #ifndef _MVME_CLOCKVAR_H
40 #define _MVME_CLOCKVAR_H
41 
42 #include <dev/clock_subr.h>
43 #include <dev/ic/mk48txxreg.h>
44 
45 /*
46  * Defintions exported to ASIC-specific clock attachment.
47  */
48 
49 extern	struct evcnt clock_profcnt;
50 extern	struct evcnt clock_statcnt;
51 
52 extern	int clock_statvar;
53 extern	int clock_statmin;
54 
55 struct clock_attach_args {
56 	void			(*ca_initfunc) __P((void *, int, int));
57 	long			(*ca_microtime) __P((void *));
58 	void			*ca_arg;
59 };
60 
61 void	clock_config __P((struct device *, struct clock_attach_args *,
62 			struct evcnt *));
63 
64 void	clock_rtc_config __P((todr_chip_handle_t));
65 
66 /*
67  * Macro to compute a new randomized interval.  The intervals are
68  * uniformly distributed on [statint - statvar / 2, statint + statvar / 2],
69  * and therefore have mean statint, giving a stathz frequency clock.
70  *
71  * This is gratuitously stolen from sparc/sparc/clock.c
72  */
73 #define CLOCK_NEWINT(statvar, statmin)	({				\
74 		u_long r, var = (statvar);				\
75 		do { r = random() & (var - 1); } while (r == 0);	\
76 		(statmin + r);						\
77 	})
78 
79 /*
80  * Sun chose the year `68' as their base count, so that
81  * cl_year==0 means 1968.
82  */
83 #define YEAR0   1968
84 
85 /*
86  * interrupt level for clock
87  */
88 #define CLOCK_LEVEL 5
89 
90 #endif /* _MVME_CLOCKVAR_H */
91