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      1 /*	$NetBSD: clock.c,v 1.14 2023/02/03 23:13:01 tsutsui Exp $	*/
      2 /*
      3  * Copyright (c) 1998 Darrin B. Jewell
      4  * All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25  */
     26 
     27 #include <sys/cdefs.h>
     28 __KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.14 2023/02/03 23:13:01 tsutsui Exp $");
     29 
     30 #include <sys/param.h>
     31 #include <sys/systm.h>
     32 #include <sys/kernel.h>
     33 #include <sys/tty.h>
     34 #include <sys/device.h>
     35 
     36 #include <machine/psl.h>
     37 #include <machine/bus.h>
     38 #include <machine/cpu.h>
     39 
     40 #include <next68k/dev/clockreg.h>
     41 #include <next68k/dev/intiovar.h>
     42 
     43 #include <next68k/next68k/rtc.h>
     44 #include <next68k/next68k/isr.h>
     45 
     46 /* @@@ This is pretty bogus and will need fixing once
     47  * things are working better.
     48  * -- jewell (at) mit.edu
     49  */
     50 
     51 int clock_intr(void *);
     52 
     53 int
     54 clock_intr(void *arg)
     55 {
     56 	volatile struct timer_reg *timer;
     57 	int whilecount = 0;
     58 
     59 	if (!INTR_OCCURRED(NEXT_I_TIMER)) {
     60 		return 0;
     61 	}
     62 
     63 	do {
     64 		static int in_hardclock = 0;
     65 		int s;
     66 
     67 		timer = (volatile struct timer_reg *)IIOV(NEXT_P_TIMER);
     68 		timer->csr |= TIMER_REG_UPDATE;
     69 
     70 		if (!in_hardclock) {
     71 			in_hardclock = 1;
     72 			s = splclock ();
     73 			hardclock(arg);
     74 			splx(s);
     75 			in_hardclock = 0;
     76 		}
     77 		if (whilecount++ > 10)
     78 			panic ("whilecount");
     79 	} while (INTR_OCCURRED(NEXT_I_TIMER));
     80 	return 1;
     81 }
     82 
     83 /*
     84  * Set up the real-time and statistics clocks.  Leave stathz 0 only
     85  * if no alternative timer is available.
     86  *
     87  * The frequencies of these clocks must be an even number of microseconds.
     88  */
     89 void
     90 cpu_initclocks(void)
     91 {
     92 	int s, cnt;
     93 	volatile struct timer_reg *timer;
     94 
     95 	rtc_init();
     96 	hz = 100;
     97 	s = splclock();
     98 	timer = (volatile struct timer_reg *)IIOV(NEXT_P_TIMER);
     99 	cnt = 1000000/hz;          /* usec timer */
    100 	timer->csr = 0;
    101 	timer->msb = (cnt >> 8);
    102 	timer->lsb = cnt;
    103 	timer->csr = TIMER_REG_ENABLE|TIMER_REG_UPDATE;
    104 	isrlink_autovec(clock_intr, NULL, NEXT_I_IPL(NEXT_I_TIMER), 0, NULL);
    105 	INTR_ENABLE(NEXT_I_TIMER);
    106 	splx(s);
    107 }
    108 
    109 
    110 void
    111 setstatclockrate(int newhz)
    112 {
    113 
    114 	/* XXX should we do something here? XXX */
    115 }
    116 
    117 /*
    118  * @@@ update this to use the usec timer
    119  * Darrin B Jewell <jewell (at) mit.edu>  Sun Feb  8 05:01:02 1998
    120  * XXX: Well, there is no more microtime.  But if there is a hardware
    121  * timer of any sort, it could be added.   ENODOCS.  gdamore.
    122  */
    123 
    124