/* $NetBSD: clock.c,v 1.59 2023/12/20 00:40:42 thorpej Exp $ */
/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1982, 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* 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. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
*
* from: Utah $Hdr: clock.c 1.18 91/01/21$
*
* @(#)clock.c 7.6 (Berkeley) 5/7/91
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.59 2023/12/20 00:40:42 thorpej Exp $");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/systm.h>
#include <sys/timetc.h>
#include <machine/psl.h>
#include <machine/cpu.h>
#include <amiga/amiga/device.h>
#include <amiga/amiga/custom.h>
#include <amiga/amiga/cia.h>
#ifdef DRACO
#include <amiga/amiga/drcustom.h>
#include <m68k/include/asm_single.h>
#endif
#include <amiga/dev/rtc.h>
#include <amiga/dev/zbusvar.h>
#if defined(PROF) && defined(PROFTIMER)
#include <sys/PROF.h>
#endif
/*
* Machine-dependent clock routines.
*
* Startrtclock restarts the real-time clock, which provides
* hardclock interrupts to kern_clock.c.
*
* Inittodr initializes the time of day hardware which provides
* date functions.
*
* Resettodr restores the time of day hardware after a time change.
*
* A note on the real-time clock:
* We actually load the clock with amiga_clk_interval-1 instead of amiga_clk_interval.
* This is because the counter decrements to zero after N+1 enabled clock
* periods where N is the value loaded into the counter.
*/
int clockmatch(device_t, cfdata_t, void *);
void clockattach(device_t, device_t, void *);
void cpu_initclocks(void);
static void calibrate_delay(device_t);
/* the clocks run at NTSC: 715.909kHz or PAL: 709.379kHz.
We're using a 100 Hz clock. */
int amiga_clk_interval;
int eclockfreq;
struct CIA *clockcia;
static u_int clk_getcounter(struct timecounter *);
static struct timecounter clk_timecounter = {
.tc_get_timecount = clk_getcounter,
.tc_counter_mask = ~0u,
.tc_quality = 100,
};
CFATTACH_DECL_NEW(clock, 0,
clockmatch, clockattach, NULL, NULL);
int
clockmatch(device_t parent, cfdata_t cf, void *aux)
{
if (matchname("clock", aux))
return(1);
return(0);
}
/*
* Start the real-time clock.
*/
void
clockattach(device_t parent, device_t self, void *aux)
{
const char *clockchip;
unsigned short interval;
int chipfreq;
#ifdef DRACO
u_char dracorev;
#endif
if (eclockfreq == 0)
eclockfreq = 715909; /* guess NTSC */
chipfreq = eclockfreq;
#ifdef DRACO
dracorev = is_draco();
if (dracorev >= 4) {
chipfreq = eclockfreq / 7;
clockchip = "QuickLogic";
} else if (dracorev) {
clockcia = (struct CIA *)CIAAbase;
clockchip = "CIA A";
} else
#endif
{
clockcia = (struct CIA *)CIABbase;
clockchip = "CIA B";
}
/* round nearest to mitigate clock drift for PAL */
amiga_clk_interval = chipfreq / hz;
if (chipfreq % hz >= hz / 2)
amiga_clk_interval++;
if (self != NULL) { /* real autoconfig? */
printf(": %s system hz %d hardware hz %d\n", clockchip, hz,
chipfreq);
clk_timecounter.tc_name = clockchip;
clk_timecounter.tc_frequency = chipfreq;
tc_init(&clk_timecounter);
}
#ifdef DRACO
if (dracorev >= 4) {
/*
* can't preload anything beforehand, timer is free_running;
* but need this for delay calibration.
*/
draco_ioct->io_timerlo = amiga_clk_interval & 0xff;
draco_ioct->io_timerhi = amiga_clk_interval >> 8;
calibrate_delay(self);
return;
}
#endif
/*
* stop timer A
*/
clockcia->cra = clockcia->cra & 0xc0;
clockcia->icr = 1 << 0; /* disable timer A interrupt */
interval = clockcia->icr; /* and make sure it's clear */
/*
* load interval into registers.
* the clocks run at NTSC: 715.909kHz or PAL: 709.379kHz
*/
interval = amiga_clk_interval - 1;
/*
* order of setting is important !
*/
clockcia->talo = interval & 0xff;
clockcia->tahi = interval >> 8;
/*
* start timer A in continuous mode
*/
clockcia->cra = (clockcia->cra & 0xc0) | 1;
calibrate_delay(self);
}
void
cpu_initclocks(void)
{
#ifdef DRACO
unsigned char dracorev;
dracorev = is_draco();
if (dracorev >= 4) {
draco_ioct->io_timerlo = amiga_clk_interval & 0xFF;
draco_ioct->io_timerhi = amiga_clk_interval >> 8;
draco_ioct->io_timerrst = 0; /* any value resets */
single_inst_bset_b(draco_ioct->io_status2, DRSTAT2_TMRINTENA);
return;
}
#endif
/*
* enable interrupts for timer A
*/
clockcia->icr = (1<<7) | (1<<0);
/*
* start timer A in continuous shot mode
*/
clockcia->cra = (clockcia->cra & 0xc0) | 1;
/*
* and globally enable interrupts for ciab
*/
#ifdef DRACO
if (dracorev) /* we use cia a on DraCo */
single_inst_bset_b(*draco_intena, DRIRQ_INT2);
else
#endif
custom.intena = INTF_SETCLR | INTF_EXTER;
}
void
setstatclockrate(int hertz)
{
}
/*
* Returns ticks since last recorded clock "tick"
* (i.e. clock interrupt).
*/
static u_int
clk_gettick(void)
{
u_int interval;
u_char hi, hi2, lo;
#ifdef DRACO
if (is_draco() >= 4) {
hi2 = draco_ioct->io_chiprev; /* latch timer */
hi = draco_ioct->io_timerhi;
lo = draco_ioct->io_timerlo;
interval = ((hi<<8) | lo);
if (interval > amiga_clk_interval) /* timer underflow */
interval = 65536 + amiga_clk_interval - interval;
else
interval = amiga_clk_interval - interval;
} else
#endif
{
hi = clockcia->tahi;
lo = clockcia->talo;
hi2 = clockcia->tahi;
if (hi != hi2) {
lo = clockcia->talo;
hi = hi2;
}
interval = (amiga_clk_interval - 1) - ((hi<<8) | lo);
/*
* should read ICR and if there's an int pending, adjust
* interval. However, since reading ICR clears the interrupt,
* we'd lose a hardclock int, and this is not tolerable.
*/
}
return interval;
}
static u_int
clk_getcounter(struct timecounter *tc)
{
static int prev_hardclock;
static u_int prev_counter;
int cur_hardclock;
u_int counter;
do {
cur_hardclock = getticks();
counter = clk_gettick();
} while (cur_hardclock != getticks());
/*
* Handle the situation of a wrapped interval counter, while
* the hardclock() interrupt was not yet executed to update
* hardclock_ticks.
*/
if (cur_hardclock < prev_hardclock)
cur_hardclock = prev_hardclock;
if (counter < prev_counter && cur_hardclock == prev_hardclock)
cur_hardclock++;
prev_hardclock = cur_hardclock;
prev_counter = counter;
return cur_hardclock * amiga_clk_interval + counter;
}
/*
* Calibrate delay loop.
* We use two iterations because we don't have enough bits to do a factor of
* 8 with better than 1%.
*
* XXX Note that we MUST stay below 1 tick if using clk_gettick(), even for
* underestimated values of delaydivisor.
*
* XXX the "ns" below is only correct for a shift of 10 bits, and even then
* off by 2.4%
*/
static void
calibrate_delay(device_t self)
{
unsigned long t1, t2;
extern u_int32_t delaydivisor;
/* XXX this should be defined elsewhere */
if (self)
printf("Calibrating delay loop... ");
do {
t1 = clk_gettick();
delay(1024);
t2 = clk_gettick();
} while (t2 <= t1);
t2 = ((t2 - t1) * 1000000) / (amiga_clk_interval * hz);
delaydivisor = (delaydivisor * t2 + 1023) >> 10;
#ifdef DEBUG
if (self)
printf("\ndiff %ld us, new divisor %u/1024 us\n", t2,
delaydivisor);
do {
t1 = clk_gettick();
delay(1024);
t2 = clk_gettick();
} while (t2 <= t1);
t2 = ((t2 - t1) * 1000000) / (amiga_clk_interval * hz);
delaydivisor = (delaydivisor * t2 + 1023) >> 10;
if (self)
printf("diff %ld us, new divisor %u/1024 us\n", t2,
delaydivisor);
#endif
do {
t1 = clk_gettick();
delay(1024);
t2 = clk_gettick();
} while (t2 <= t1);
t2 = ((t2 - t1) * 1000000) / (amiga_clk_interval * hz);
delaydivisor = (delaydivisor * t2 + 1023) >> 10;
#ifdef DEBUG
if (self)
printf("diff %ld us, new divisor ", t2);
#endif
if (self)
printf("%u/1024 us\n", delaydivisor);
}
#if notyet
/* implement this later. I'd suggest using both timers in CIA-A, they're
not yet used. */
#include "clock.h"
#if NCLOCK > 0
/*
* /dev/clock: mappable high resolution timer.
*
* This code implements a 32-bit recycling counter (with a 4 usec period)
* using timers 2 & 3 on the 6840 clock chip. The counter can be mapped
* RO into a user's address space to achieve low overhead (no system calls),
* high-precision timing.
*
* Note that timer 3 is also used for the high precision profiling timer
* (PROFTIMER code above). Care should be taken when both uses are
* configured as only a token effort is made to avoid conflicting use.
*/
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/ioctl.h>
#include <uvm/uvm_extern.h>
#include <amiga/amiga/clockioctl.h>
#include <sys/specdev.h>
#include <sys/vnode.h>
#include <sys/mman.h>
int clockon = 0; /* non-zero if high-res timer enabled */
#ifdef PROFTIMER
int profprocs = 0; /* # of procs using profiling timer */
#endif
#ifdef DEBUG
int clockdebug = 0;
#endif
/*ARGSUSED*/
int
clockopen(dev_t dev, int flags)
{
#ifdef PROFTIMER
#ifdef PROF
/*
* Kernel profiling enabled, give up.
*/
if (profiling)
return(EBUSY);
#endif
/*
* If any user processes are profiling, give up.
*/
if (profprocs)
return(EBUSY);
#endif
if (!clockon) {
startclock();
clockon++;
}
return(0);
}
/*ARGSUSED*/
int
clockclose(dev_t dev, int flags)
{
(void) clockunmmap(dev, (void *)0, curproc); /* XXX */
stopclock();
clockon = 0;
return(0);
}
/*ARGSUSED*/
int
clockioctl(dev_t dev, u_long cmd, void *data, int flag, struct proc *p)
{
int error = 0;
switch (cmd) {
case CLOCKMAP:
error = clockmmap(dev, (void **)data, p);
break;
case CLOCKUNMAP:
error = clockunmmap(dev, *(void **)data, p);
break;
case CLOCKGETRES:
*(int *)data = CLK_RESOLUTION;
break;
default:
error = EINVAL;
break;
}
return(error);
}
/*ARGSUSED*/
void
clockmap(dev_t dev, int off, int prot)
{
return MD_BTOP(off + (INTIOBASE+CLKBASE+CLKSR-1));
}
int
clockmmap(dev_t dev, void **addrp, struct proc *p)
{
int error;
struct vnode vn;
struct specinfo si;
int flags;
flags = MAP_FILE|MAP_SHARED;
if (*addrp)
flags |= MAP_FIXED;
else
*addrp = (void *)0x1000000; /* XXX */
vn.v_type = VCHR; /* XXX */
vn.v_specinfo = &si; /* XXX */
vn.v_rdev = dev; /* XXX */
error = vm_mmap(&p->p_vmspace->vm_map, (vm_offset_t *)addrp,
PAGE_SIZE, VM_PROT_ALL, flags, (void *)&vn, 0);
return(error);
}
int
clockunmmap(dev_t dev, void *addr, struct proc *p)
{
int rv;
if (addr == 0)
return(EINVAL); /* XXX: how do we deal with this? */
uvm_deallocate(p->p_vmspace->vm_map, (vm_offset_t)addr, PAGE_SIZE);
return 0;
}
void
startclock(void)
{
register struct clkreg *clk = (struct clkreg *)clkstd[0];
clk->clk_msb2 = -1; clk->clk_lsb2 = -1;
clk->clk_msb3 = -1; clk->clk_lsb3 = -1;
clk->clk_cr2 = CLK_CR3;
clk->clk_cr3 = CLK_OENAB|CLK_8BIT;
clk->clk_cr2 = CLK_CR1;
clk->clk_cr1 = CLK_IENAB;
}
void
stopclock(void)
{
register struct clkreg *clk = (struct clkreg *)clkstd[0];
clk->clk_cr2 = CLK_CR3;
clk->clk_cr3 = 0;
clk->clk_cr2 = CLK_CR1;
clk->clk_cr1 = CLK_IENAB;
}
#endif
#endif
#ifdef PROFTIMER
/*
* This code allows the amiga kernel to use one of the extra timers on
* the clock chip for profiling, instead of the regular system timer.
* The advantage of this is that the profiling timer can be turned up to
* a higher interrupt rate, giving finer resolution timing. The profclock
* routine is called from the lev6intr in locore, and is a specialized
* routine that calls addupc. The overhead then is far less than if
* hardclock/softclock was called. Further, the context switch code in
* locore has been changed to turn the profile clock on/off when switching
* into/out of a process that is profiling (startprofclock/stopprofclock).
* This reduces the impact of the profiling clock on other users, and might
* possibly increase the accuracy of the profiling.
*/
int profint = PRF_INTERVAL; /* Clock ticks between interrupts */
int profscale = 0; /* Scale factor from sys clock to prof clock */
char profon = 0; /* Is profiling clock on? */
/* profon values - do not change, locore.s assumes these values */
#define PRF_NONE 0x00
#define PRF_USER 0x01
#define PRF_KERNEL 0x80
void
initprofclock(void)
{
#if NCLOCK > 0
struct proc *p = curproc; /* XXX */
/*
* If the high-res timer is running, force profiling off.
* Unfortunately, this gets reflected back to the user not as
* an error but as a lack of results.
*/
if (clockon) {
p->p_stats->p_prof.pr_scale = 0;
return;
}
/*
* Keep track of the number of user processes that are profiling
* by checking the scale value.
*
* XXX: this all assumes that the profiling code is well behaved;
* i.e. profil() is called once per process with pcscale non-zero
* to turn it on, and once with pcscale zero to turn it off.
* Also assumes you don't do any forks or execs. Oh well, there
* is always adb...
*/
if (p->p_stats->p_prof.pr_scale)
profprocs++;
else
profprocs--;
#endif
/*
* The profile interrupt interval must be an even divisor
* of the amiga_clk_interval so that scaling from a system clock
* tick to a profile clock tick is possible using integer math.
*/
if (profint > amiga_clk_interval || (amiga_clk_interval % profint) != 0)
profint = amiga_clk_interval;
profscale = amiga_clk_interval / profint;
}
void
startprofclock(void)
{
unsigned short interval;
/* stop timer B */
clockcia->crb = clockcia->crb & 0xc0;
/* load interval into registers.
the clocks run at NTSC: 715.909kHz or PAL: 709.379kHz */
interval = profint - 1;
/* order of setting is important ! */
clockcia->tblo = interval & 0xff;
clockcia->tbhi = interval >> 8;
/* enable interrupts for timer B */
clockcia->icr = (1<<7) | (1<<1);
/* start timer B in continuous shot mode */
clockcia->crb = (clockcia->crb & 0xc0) | 1;
}
void
stopprofclock(void)
{
/* stop timer B */
clockcia->crb = clockcia->crb & 0xc0;
}
#ifdef PROF
/*
* profclock() is expanded in line in lev6intr() unless profiling kernel.
* Assumes it is called with clock interrupts blocked.
*/
void
profclock(void *pc, int ps)
{
/*
* Came from user mode.
* If this process is being profiled record the tick.
*/
if (USERMODE(ps)) {
if (p->p_stats.p_prof.pr_scale)
addupc(pc, &curproc->p_stats.p_prof, 1);
}
/*
* Came from kernel (supervisor) mode.
* If we are profiling the kernel, record the tick.
*/
else if (profiling < 2) {
register int s = pc - s_lowpc;
if (s < s_textsize)
kcount[s / (HISTFRACTION * sizeof (*kcount))]++;
}
/*
* Kernel profiling was on but has been disabled.
* Mark as no longer profiling kernel and if all profiling done,
* disable the clock.
*/
if (profiling && (profon & PRF_KERNEL)) {
profon &= ~PRF_KERNEL;
if (profon == PRF_NONE)
stopprofclock();
}
}
#endif
#endif
