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ofwgencfg_clock.c revision 1.3
      1 /*	$NetBSD: ofwgencfg_clock.c,v 1.3 2002/09/27 15:35:49 provos Exp $	*/
      2 
      3 /*
      4  * Copyright 1997
      5  * Digital Equipment Corporation. All rights reserved.
      6  *
      7  * This software is furnished under license and may be used and
      8  * copied only in accordance with the following terms and conditions.
      9  * Subject to these conditions, you may download, copy, install,
     10  * use, modify and distribute this software in source and/or binary
     11  * form. No title or ownership is transferred hereby.
     12  *
     13  * 1) Any source code used, modified or distributed must reproduce
     14  *    and retain this copyright notice and list of conditions as
     15  *    they appear in the source file.
     16  *
     17  * 2) No right is granted to use any trade name, trademark, or logo of
     18  *    Digital Equipment Corporation. Neither the "Digital Equipment
     19  *    Corporation" name nor any trademark or logo of Digital Equipment
     20  *    Corporation may be used to endorse or promote products derived
     21  *    from this software without the prior written permission of
     22  *    Digital Equipment Corporation.
     23  *
     24  * 3) This software is provided "AS-IS" and any express or implied
     25  *    warranties, including but not limited to, any implied warranties
     26  *    of merchantability, fitness for a particular purpose, or
     27  *    non-infringement are disclaimed. In no event shall DIGITAL be
     28  *    liable for any damages whatsoever, and in particular, DIGITAL
     29  *    shall not be liable for special, indirect, consequential, or
     30  *    incidental damages or damages for lost profits, loss of
     31  *    revenue or loss of use, whether such damages arise in contract,
     32  *    negligence, tort, under statute, in equity, at law or otherwise,
     33  *    even if advised of the possibility of such damage.
     34  */
     35 
     36 /* Include header files */
     37 
     38 #include <sys/types.h>
     39 #include <sys/param.h>
     40 #include <sys/systm.h>
     41 #include <sys/kernel.h>
     42 #include <sys/time.h>
     43 
     44 #include <machine/intr.h>
     45 #include <arm/cpufunc.h>
     46 #include <machine/cpu.h>
     47 #include <machine/ofw.h>
     48 
     49 static void *clockirq;
     50 
     51 
     52 /*
     53  * int clockhandler(struct clockframe *frame)
     54  *
     55  * Function called by timer 0 interrupts. This just calls
     56  * hardclock(). Eventually the irqhandler can call hardclock() directly
     57  * but for now we use this function so that we can debug IRQ's
     58  */
     59 
     60 int
     61 clockhandler(frame)
     62 	struct clockframe *frame;
     63 {
     64 
     65 	hardclock(frame);
     66 	return(0);	/* Pass the interrupt on down the chain */
     67 }
     68 
     69 
     70 /*
     71  * int statclockhandler(struct clockframe *frame)
     72  *
     73  * Function called by timer 1 interrupts. This just calls
     74  * statclock(). Eventually the irqhandler can call statclock() directly
     75  * but for now we use this function so that we can debug IRQ's
     76  */
     77 
     78 int
     79 statclockhandler(frame)
     80 	struct clockframe *frame;
     81 {
     82 
     83 	statclock(frame);
     84 	return(0);	/* Pass the interrupt on down the chain */
     85 }
     86 
     87 
     88 /*
     89  * void setstatclockrate(int hz)
     90  *
     91  * Set the stat clock rate. The stat clock uses timer1
     92  */
     93 
     94 void
     95 setstatclockrate(hz)
     96 	int hz;
     97 {
     98 
     99 #ifdef	OFWGENCFG
    100 	printf("Not setting statclock: OFW generic has only one clock.\n");
    101 #endif
    102 }
    103 
    104 
    105 /*
    106  * void cpu_initclocks(void)
    107  *
    108  * Initialise the clocks.
    109  * This sets up the two timers in the IOMD and installs the IRQ handlers
    110  *
    111  * NOTE: Currently only timer 0 is setup and the IRQ handler is not installed
    112  */
    113 
    114 void
    115 cpu_initclocks()
    116 {
    117 	/*
    118 	 * Load timer 0 with count down value
    119 	 * This timer generates 100Hz interrupts for the system clock
    120 	 */
    121 
    122 	printf("clock: hz=%d stathz = %d profhz = %d\n", hz, stathz, profhz);
    123 
    124         clockirq = intr_claim(IRQ_TIMER0, IPL_CLOCK, "tmr0 hard clk",
    125             clockhandler, 0);
    126         if (clockirq == NULL)
    127                 panic("Cannot installer timer 0 IRQ handler");
    128 
    129 	/* Notify callback handler that it can start processing ticks. */
    130 	ofw_handleticks = 1;
    131 
    132 	if (stathz) {
    133 	    printf("Not installing statclock: OFW generic has only one clock.\n");
    134 	}
    135 }
    136 
    137 
    138 /*
    139  * void microtime(struct timeval *tvp)
    140  *
    141  * Fill in the specified timeval struct with the current time
    142  * accurate to the microsecond.
    143  */
    144 
    145 void
    146 microtime(tvp)
    147 	struct timeval *tvp;
    148 {
    149 	int s;
    150 	static struct timeval oldtv;
    151 
    152 	s = splhigh();
    153 
    154 	/* Fill in the timeval struct */
    155 
    156 	*tvp = time;
    157 
    158 	/* Make sure the micro seconds don't overflow. */
    159 
    160 	while (tvp->tv_usec >= 1000000) {
    161 		tvp->tv_usec -= 1000000;
    162 		++tvp->tv_sec;
    163 	}
    164 
    165 	/* Make sure the time has advanced. */
    166 
    167 	if (tvp->tv_sec == oldtv.tv_sec &&
    168 	    tvp->tv_usec <= oldtv.tv_usec) {
    169 		tvp->tv_usec = oldtv.tv_usec + 1;
    170 		if (tvp->tv_usec >= 1000000) {
    171 			tvp->tv_usec -= 1000000;
    172 			++tvp->tv_sec;
    173 		}
    174 	}
    175 
    176 
    177 	oldtv = *tvp;
    178 	(void)splx(s);
    179 }
    180 
    181 /*
    182  * Estimated loop for n microseconds
    183  */
    184 
    185 /* Need to re-write this to use the timers */
    186 
    187 /* One day soon I will actually do this */
    188 
    189 int delaycount = 50;
    190 
    191 void
    192 delay(n)
    193 	u_int n;
    194 {
    195 	u_int i;
    196 
    197 	if (n == 0) return;
    198 	while (n-- > 0) {
    199 		if (cputype == CPU_ID_SA110)	/* XXX - Seriously gross hack */
    200 			for (i = delaycount; --i;);
    201 		else
    202 			for (i = 8; --i;);
    203 	}
    204 }
    205