/* $NetBSD: clock.c,v 1.11 2006/09/11 15:07:50 gdamore Exp $ */ /* * Copyright (c) 1998 Darrin B. Jewell * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Darrin B. Jewell * 4. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include <sys/cdefs.h> __KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.11 2006/09/11 15:07:50 gdamore Exp $"); #include <sys/param.h> #include <sys/systm.h> #include <sys/kernel.h> #include <sys/tty.h> #include <sys/device.h> #include <machine/psl.h> #include <machine/bus.h> #include <machine/cpu.h> #include <next68k/dev/clockreg.h> #include <next68k/dev/intiovar.h> #include <next68k/next68k/rtc.h> #include <next68k/next68k/isr.h> /* @@@ This is pretty bogus and will need fixing once * things are working better. * -- jewell@mit.edu */ /* * Note that the value of delay_divisor is roughly * 2048 / cpuspeed (where cpuspeed is in MHz) on 68020 * and 68030 systems. See clock.c for the delay * calibration algorithm. */ int cpuspeed; /* relative cpu speed; XXX skewed on 68040 */ int delay_divisor = 2048/25; /* delay constant */ /* * Calibrate the delay constant. */ void next68k_calibrate_delay(void) { extern int delay_divisor; /* @@@ write this once we know how to read * a real time clock */ /* * Sanity check the delay_divisor value. If we totally lost, * assume a 25MHz CPU; */ if (delay_divisor == 0) delay_divisor = 2048 / 25; /* Calculate CPU speed. */ cpuspeed = 2048 / delay_divisor; } int clock_intr(void *); int clock_intr(void *arg) { volatile struct timer_reg *timer; int whilecount = 0; if (!INTR_OCCURRED(NEXT_I_TIMER)) { return(0); } do { static int in_hardclock = 0; int s; timer = (volatile struct timer_reg *)IIOV(NEXT_P_TIMER); timer->csr |= TIMER_REG_UPDATE; if (! in_hardclock) { in_hardclock = 1; s = splclock (); hardclock(arg); splx(s); in_hardclock = 0; } if (whilecount++ > 10) panic ("whilecount"); } while (INTR_OCCURRED(NEXT_I_TIMER)); return(1); } /* * Set up the real-time and statistics clocks. Leave stathz 0 only * if no alternative timer is available. * * The frequencies of these clocks must be an even number of microseconds. */ void cpu_initclocks(void) { int s, cnt; volatile struct timer_reg *timer; rtc_init(); hz = 100; s = splclock(); timer = (volatile struct timer_reg *)IIOV(NEXT_P_TIMER); cnt = 1000000/hz; /* usec timer */ timer->csr = 0; timer->msb = (cnt >> 8); timer->lsb = cnt; timer->csr = TIMER_REG_ENABLE|TIMER_REG_UPDATE; isrlink_autovec(clock_intr, NULL, NEXT_I_IPL(NEXT_I_TIMER), 0, NULL); INTR_ENABLE(NEXT_I_TIMER); splx(s); } void setstatclockrate(int newhz) { /* XXX should we do something here? XXX */ } /* @@@ update this to use the usec timer * Darrin B Jewell <jewell@mit.edu> Sun Feb 8 05:01:02 1998 * XXX: Well, there is no more microtime. But if there is a hardware * timer of any sort, it could be added. ENODOCS. gdamore. */