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      1 /*	$NetBSD: clockvar.h,v 1.9 2009/05/12 14:38:26 cegger 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  *
     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 _MVME_CLOCKVAR_H
     33 #define _MVME_CLOCKVAR_H
     34 
     35 #include <dev/clock_subr.h>
     36 
     37 /*
     38  * Definitions exported to ASIC-specific clock attachment.
     39  */
     40 
     41 extern	struct evcnt clock_profcnt;
     42 extern	struct evcnt clock_statcnt;
     43 
     44 extern	int clock_statvar;
     45 extern	int clock_statmin;
     46 
     47 struct clock_attach_args {
     48 	void			(*ca_initfunc)(void *, int, int);
     49 	void			*ca_arg;
     50 };
     51 
     52 void	clock_config(device_t, struct clock_attach_args *,
     53 			struct evcnt *);
     54 
     55 /*
     56  * Macro to compute a new randomized interval.  The intervals are
     57  * uniformly distributed on [statint - statvar / 2, statint + statvar / 2],
     58  * and therefore have mean statint, giving a stathz frequency clock.
     59  *
     60  * This is gratuitously stolen from sparc/sparc/clock.c
     61  */
     62 #define CLOCK_NEWINT(statvar, statmin)	({				\
     63 		u_long r, var = (statvar);				\
     64 		do { r = random() & (var - 1); } while (r == 0);	\
     65 		(statmin + r);						\
     66 	})
     67 
     68 /*
     69  * Sun chose the year `68' as their base count, so that
     70  * cl_year==0 means 1968.
     71  */
     72 #define YEAR0   1968
     73 
     74 /*
     75  * interrupt level for clock
     76  */
     77 #define CLOCK_LEVEL 5
     78 
     79 #endif /* _MVME_CLOCKVAR_H */
     80