sys/dev/mvme/clockvar.h

   1 /*      $NetBSD: clockvar.h,v 1.8 2008/04/28 20:23:54 martin 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 */