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clockvar.h revision 1.5 
      1 /*	$NetBSD: clockvar.h,v 1.5 2005/02/04 02:10:43 perry 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