xref: /netbsd-src/sys/dev/mvme/clockvar.h (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: clockvar.h,v 1.6 2005/12/11 12:22:47 christos 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 
44 /*
45  * Definitions exported to ASIC-specific clock attachment.
46  */
47 
48 extern	struct evcnt clock_profcnt;
49 extern	struct evcnt clock_statcnt;
50 
51 extern	int clock_statvar;
52 extern	int clock_statmin;
53 
54 struct clock_attach_args {
55 	void			(*ca_initfunc)(void *, int, int);
56 	long			(*ca_microtime)(void *);
57 	void			*ca_arg;
58 };
59 
60 void	clock_config(struct device *, struct clock_attach_args *,
61 			struct evcnt *);
62 
63 /*
64  * Macro to compute a new randomized interval.  The intervals are
65  * uniformly distributed on [statint - statvar / 2, statint + statvar / 2],
66  * and therefore have mean statint, giving a stathz frequency clock.
67  *
68  * This is gratuitously stolen from sparc/sparc/clock.c
69  */
70 #define CLOCK_NEWINT(statvar, statmin)	({				\
71 		u_long r, var = (statvar);				\
72 		do { r = random() & (var - 1); } while (r == 0);	\
73 		(statmin + r);						\
74 	})
75 
76 /*
77  * Sun chose the year `68' as their base count, so that
78  * cl_year==0 means 1968.
79  */
80 #define YEAR0   1968
81 
82 /*
83  * interrupt level for clock
84  */
85 #define CLOCK_LEVEL 5
86 
87 #endif /* _MVME_CLOCKVAR_H */
88