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ofwgencfg_clock.c revision 1.7 
      1 /*	$NetBSD: ofwgencfg_clock.c,v 1.7 2007/03/08 20:48:39 matt 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/cdefs.h>
     39 __KERNEL_RCSID(0, "$NetBSD: ofwgencfg_clock.c,v 1.7 2007/03/08 20:48:39 matt Exp $");
     40 
     41 #include <sys/types.h>
     42 #include <sys/param.h>
     43 #include <sys/systm.h>
     44 #include <sys/kernel.h>
     45 #include <sys/time.h>
     46 
     47 #include <machine/intr.h>
     48 #include <machine/irqhandler.h>
     49 #include <arm/cpufunc.h>
     50 #include <machine/cpu.h>
     51 #include <machine/ofw.h>
     52 
     53 static void *clockirq;
     54 
     55 
     56 /*
     57  * int clockhandler(struct clockframe *frame)
     58  *
     59  * Function called by timer 0 interrupts. This just calls
     60  * hardclock(). Eventually the irqhandler can call hardclock() directly
     61  * but for now we use this function so that we can debug IRQ's
     62  */
     63 
     64 static int
     65 clockhandler(struct clockframe *frame)
     66 {
     67 
     68 	hardclock(frame);
     69 	return(0);	/* Pass the interrupt on down the chain */
     70 }
     71 
     72 #if 0
     73 /*
     74  * int statclockhandler(struct clockframe *frame)
     75  *
     76  * Function called by timer 1 interrupts. This just calls
     77  * statclock(). Eventually the irqhandler can call statclock() directly
     78  * but for now we use this function so that we can debug IRQ's
     79  */
     80 
     81 int
     82 statclockhandler(frame)
     83 	struct clockframe *frame;
     84 {
     85 
     86 	statclock(frame);
     87 	return(0);	/* Pass the interrupt on down the chain */
     88 }
     89 #endif
     90 
     91 /*
     92  * void setstatclockrate(int hz)
     93  *
     94  * Set the stat clock rate. The stat clock uses timer1
     95  */
     96 
     97 void
     98 setstatclockrate(int arg)
     99 {
    100 #ifdef	OFWGENCFG
    101 	printf("Not setting statclock: OFW generic has only one clock.\n");
    102 #endif
    103 }
    104 
    105 
    106 /*
    107  * void cpu_initclocks(void)
    108  *
    109  * Initialise the clocks.
    110  * This sets up the two timers in the IOMD and installs the IRQ handlers
    111  *
    112  * NOTE: Currently only timer 0 is setup and the IRQ handler is not installed
    113  */
    114 
    115 void
    116 cpu_initclocks()
    117 {
    118 	/*
    119 	 * Load timer 0 with count down value
    120 	 * This timer generates 100Hz interrupts for the system clock
    121 	 */
    122 
    123 	printf("clock: hz=%d stathz = %d profhz = %d\n", hz, stathz, profhz);
    124 
    125         clockirq = intr_claim(IRQ_TIMER0, IPL_CLOCK,
    126             (int (*)(void *))clockhandler, 0, "clock", "hard intr");
    127         if (clockirq == NULL)
    128                 panic("Cannot installer timer 0 IRQ handler");
    129 
    130 	/* Notify callback handler that it can start processing ticks. */
    131 	ofw_handleticks = 1;
    132 
    133 	if (stathz) {
    134 	    printf("Not installing statclock: OFW generic has only one clock.\n");
    135 	}
    136 }
    137 
    138 
    139 /*
    140  * void microtime(struct timeval *tvp)
    141  *
    142  * Fill in the specified timeval struct with the current time
    143  * accurate to the microsecond.
    144  */
    145 
    146 void
    147 microtime(tvp)
    148 	struct timeval *tvp;
    149 {
    150 	int s;
    151 	static struct timeval oldtv;
    152 
    153 	s = splhigh();
    154 
    155 	/* Fill in the timeval struct */
    156 
    157 	*tvp = time;
    158 
    159 	/* Make sure the micro seconds don't overflow. */
    160 
    161 	while (tvp->tv_usec >= 1000000) {
    162 		tvp->tv_usec -= 1000000;
    163 		++tvp->tv_sec;
    164 	}
    165 
    166 	/* Make sure the time has advanced. */
    167 
    168 	if (tvp->tv_sec == oldtv.tv_sec &&
    169 	    tvp->tv_usec <= oldtv.tv_usec) {
    170 		tvp->tv_usec = oldtv.tv_usec + 1;
    171 		if (tvp->tv_usec >= 1000000) {
    172 			tvp->tv_usec -= 1000000;
    173 			++tvp->tv_sec;
    174 		}
    175 	}
    176 
    177 
    178 	oldtv = *tvp;
    179 	(void)splx(s);
    180 }
    181 
    182 /*
    183  * Estimated loop for n microseconds
    184  */
    185 
    186 /* Need to re-write this to use the timers */
    187 
    188 /* One day soon I will actually do this */
    189 
    190 int delaycount = 50;
    191 
    192 void
    193 delay(n)
    194 	u_int n;
    195 {
    196 	u_int i;
    197 
    198 	if (n == 0) return;
    199 	while (n-- > 0) {
    200 		if (cputype == CPU_ID_SA110)	/* XXX - Seriously gross hack */
    201 			for (i = delaycount; --i;);
    202 		else
    203 			for (i = 8; --i;);
    204 	}
    205 }
    206