freebsd-dev/sys/isa/atrtc.c
John Baldwin db015a9153 Fixup some more fallout from the lapic/i8254 changes:
- Make sure timer0_max_count is set to a correct value in the lapic case.
- Revert i8254_restore() to explicitly reprogram timer 0 rather than
  calling set_timer_freq() to do it.  set_timer_freq() only reprograms
  the counter if the max count changes which it never does on resume.  This
  unbreaks suspend/resume for several people.

Tested by:	marks, others
Reviewed by:	bde
MFC after:	3 days
2005-07-13 15:43:21 +00:00

967 lines
24 KiB
C

/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz and Don Ahn.
*
* 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.
* 4. 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: @(#)clock.c 7.2 (Berkeley) 5/12/91
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* Routines to handle clock hardware.
*/
/*
* inittodr, settodr and support routines written
* by Christoph Robitschko <chmr@edvz.tu-graz.ac.at>
*
* reintroduced and updated by Chris Stenton <chris@gnome.co.uk> 8/10/94
*/
#include "opt_apic.h"
#include "opt_clock.h"
#include "opt_isa.h"
#include "opt_mca.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/lock.h>
#include <sys/kdb.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/time.h>
#include <sys/timetc.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/module.h>
#include <sys/sysctl.h>
#include <sys/cons.h>
#include <sys/power.h>
#include <machine/clock.h>
#include <machine/cputypes.h>
#include <machine/frame.h>
#include <machine/intr_machdep.h>
#include <machine/md_var.h>
#include <machine/psl.h>
#ifdef DEV_APIC
#include <machine/apicvar.h>
#endif
#include <machine/specialreg.h>
#include <machine/ppireg.h>
#include <machine/timerreg.h>
#include <isa/rtc.h>
#ifdef DEV_ISA
#include <isa/isareg.h>
#include <isa/isavar.h>
#endif
#ifdef DEV_MCA
#include <i386/bios/mca_machdep.h>
#endif
/*
* 32-bit time_t's can't reach leap years before 1904 or after 2036, so we
* can use a simple formula for leap years.
*/
#define LEAPYEAR(y) (((u_int)(y) % 4 == 0) ? 1 : 0)
#define DAYSPERYEAR (31+28+31+30+31+30+31+31+30+31+30+31)
#define TIMER_DIV(x) ((timer_freq + (x) / 2) / (x))
int adjkerntz; /* local offset from GMT in seconds */
int clkintr_pending;
int disable_rtc_set; /* disable resettodr() if != 0 */
int pscnt = 1;
int psdiv = 1;
int statclock_disable;
#ifndef TIMER_FREQ
#define TIMER_FREQ 1193182
#endif
u_int timer_freq = TIMER_FREQ;
int timer0_max_count;
int timer0_real_max_count;
int wall_cmos_clock; /* wall CMOS clock assumed if != 0 */
struct mtx clock_lock;
#define RTC_LOCK mtx_lock_spin(&clock_lock)
#define RTC_UNLOCK mtx_unlock_spin(&clock_lock)
static int beeping = 0;
static const u_char daysinmonth[] = {31,28,31,30,31,30,31,31,30,31,30,31};
static struct intsrc *i8254_intsrc;
static u_int32_t i8254_lastcount;
static u_int32_t i8254_offset;
static int (*i8254_pending)(struct intsrc *);
static int i8254_ticked;
static int using_lapic_timer;
static u_char rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF;
static u_char rtc_statusb = RTCSB_24HR;
/* Values for timerX_state: */
#define RELEASED 0
#define RELEASE_PENDING 1
#define ACQUIRED 2
#define ACQUIRE_PENDING 3
static u_char timer2_state;
static unsigned i8254_get_timecount(struct timecounter *tc);
static unsigned i8254_simple_get_timecount(struct timecounter *tc);
static void set_timer_freq(u_int freq, int intr_freq);
static struct timecounter i8254_timecounter = {
i8254_get_timecount, /* get_timecount */
0, /* no poll_pps */
~0u, /* counter_mask */
0, /* frequency */
"i8254", /* name */
0 /* quality */
};
static void
clkintr(struct clockframe *frame)
{
if (timecounter->tc_get_timecount == i8254_get_timecount) {
mtx_lock_spin(&clock_lock);
if (i8254_ticked)
i8254_ticked = 0;
else {
i8254_offset += timer0_max_count;
i8254_lastcount = 0;
}
clkintr_pending = 0;
mtx_unlock_spin(&clock_lock);
}
if (!using_lapic_timer)
hardclock(frame);
#ifdef DEV_MCA
/* Reset clock interrupt by asserting bit 7 of port 0x61 */
if (MCA_system)
outb(0x61, inb(0x61) | 0x80);
#endif
}
int
acquire_timer2(int mode)
{
if (timer2_state != RELEASED)
return (-1);
timer2_state = ACQUIRED;
/*
* This access to the timer registers is as atomic as possible
* because it is a single instruction. We could do better if we
* knew the rate. Use of splclock() limits glitches to 10-100us,
* and this is probably good enough for timer2, so we aren't as
* careful with it as with timer0.
*/
outb(TIMER_MODE, TIMER_SEL2 | (mode & 0x3f));
return (0);
}
int
release_timer2()
{
if (timer2_state != ACQUIRED)
return (-1);
timer2_state = RELEASED;
outb(TIMER_MODE, TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT);
return (0);
}
/*
* This routine receives statistical clock interrupts from the RTC.
* As explained above, these occur at 128 interrupts per second.
* When profiling, we receive interrupts at a rate of 1024 Hz.
*
* This does not actually add as much overhead as it sounds, because
* when the statistical clock is active, the hardclock driver no longer
* needs to keep (inaccurate) statistics on its own. This decouples
* statistics gathering from scheduling interrupts.
*
* The RTC chip requires that we read status register C (RTC_INTR)
* to acknowledge an interrupt, before it will generate the next one.
* Under high interrupt load, rtcintr() can be indefinitely delayed and
* the clock can tick immediately after the read from RTC_INTR. In this
* case, the mc146818A interrupt signal will not drop for long enough
* to register with the 8259 PIC. If an interrupt is missed, the stat
* clock will halt, considerably degrading system performance. This is
* why we use 'while' rather than a more straightforward 'if' below.
* Stat clock ticks can still be lost, causing minor loss of accuracy
* in the statistics, but the stat clock will no longer stop.
*/
static void
rtcintr(struct clockframe *frame)
{
while (rtcin(RTC_INTR) & RTCIR_PERIOD) {
if (profprocs != 0) {
if (--pscnt == 0)
pscnt = psdiv;
profclock(frame);
}
if (pscnt == psdiv)
statclock(frame);
}
}
#include "opt_ddb.h"
#ifdef DDB
#include <ddb/ddb.h>
DB_SHOW_COMMAND(rtc, rtc)
{
printf("%02x/%02x/%02x %02x:%02x:%02x, A = %02x, B = %02x, C = %02x\n",
rtcin(RTC_YEAR), rtcin(RTC_MONTH), rtcin(RTC_DAY),
rtcin(RTC_HRS), rtcin(RTC_MIN), rtcin(RTC_SEC),
rtcin(RTC_STATUSA), rtcin(RTC_STATUSB), rtcin(RTC_INTR));
}
#endif /* DDB */
static int
getit(void)
{
int high, low;
mtx_lock_spin(&clock_lock);
/* Select timer0 and latch counter value. */
outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
low = inb(TIMER_CNTR0);
high = inb(TIMER_CNTR0);
mtx_unlock_spin(&clock_lock);
return ((high << 8) | low);
}
/*
* Wait "n" microseconds.
* Relies on timer 1 counting down from (timer_freq / hz)
* Note: timer had better have been programmed before this is first used!
*/
void
DELAY(int n)
{
int delta, prev_tick, tick, ticks_left;
#ifdef DELAYDEBUG
int getit_calls = 1;
int n1;
static int state = 0;
if (state == 0) {
state = 1;
for (n1 = 1; n1 <= 10000000; n1 *= 10)
DELAY(n1);
state = 2;
}
if (state == 1)
printf("DELAY(%d)...", n);
#endif
/*
* Guard against the timer being uninitialized if we are called
* early for console i/o.
*/
if (timer0_max_count == 0)
set_timer_freq(timer_freq, hz);
/*
* Read the counter first, so that the rest of the setup overhead is
* counted. Guess the initial overhead is 20 usec (on most systems it
* takes about 1.5 usec for each of the i/o's in getit(). The loop
* takes about 6 usec on a 486/33 and 13 usec on a 386/20. The
* multiplications and divisions to scale the count take a while).
*
* However, if ddb is active then use a fake counter since reading
* the i8254 counter involves acquiring a lock. ddb must not do
* locking for many reasons, but it calls here for at least atkbd
* input.
*/
#ifdef KDB
if (kdb_active)
prev_tick = 1;
else
#endif
prev_tick = getit();
n -= 0; /* XXX actually guess no initial overhead */
/*
* Calculate (n * (timer_freq / 1e6)) without using floating point
* and without any avoidable overflows.
*/
if (n <= 0)
ticks_left = 0;
else if (n < 256)
/*
* Use fixed point to avoid a slow division by 1000000.
* 39099 = 1193182 * 2^15 / 10^6 rounded to nearest.
* 2^15 is the first power of 2 that gives exact results
* for n between 0 and 256.
*/
ticks_left = ((u_int)n * 39099 + (1 << 15) - 1) >> 15;
else
/*
* Don't bother using fixed point, although gcc-2.7.2
* generates particularly poor code for the long long
* division, since even the slow way will complete long
* before the delay is up (unless we're interrupted).
*/
ticks_left = ((u_int)n * (long long)timer_freq + 999999)
/ 1000000;
while (ticks_left > 0) {
#ifdef KDB
if (kdb_active) {
inb(0x84);
tick = prev_tick - 1;
if (tick <= 0)
tick = timer0_max_count;
} else
#endif
tick = getit();
#ifdef DELAYDEBUG
++getit_calls;
#endif
delta = prev_tick - tick;
prev_tick = tick;
if (delta < 0) {
delta += timer0_max_count;
/*
* Guard against timer0_max_count being wrong.
* This shouldn't happen in normal operation,
* but it may happen if set_timer_freq() is
* traced.
*/
if (delta < 0)
delta = 0;
}
ticks_left -= delta;
}
#ifdef DELAYDEBUG
if (state == 1)
printf(" %d calls to getit() at %d usec each\n",
getit_calls, (n + 5) / getit_calls);
#endif
}
static void
sysbeepstop(void *chan)
{
ppi_spkr_off(); /* disable counter2 output to speaker */
timer_spkr_release();
beeping = 0;
}
int
sysbeep(int pitch, int period)
{
int x = splclock();
if (timer_spkr_acquire())
if (!beeping) {
/* Something else owns it. */
splx(x);
return (-1); /* XXX Should be EBUSY, but nobody cares anyway. */
}
mtx_lock_spin(&clock_lock);
spkr_set_pitch(pitch);
mtx_unlock_spin(&clock_lock);
if (!beeping) {
/* enable counter2 output to speaker */
ppi_spkr_on();
beeping = period;
timeout(sysbeepstop, (void *)NULL, period);
}
splx(x);
return (0);
}
/*
* RTC support routines
*/
int
rtcin(reg)
int reg;
{
u_char val;
RTC_LOCK;
outb(IO_RTC, reg);
inb(0x84);
val = inb(IO_RTC + 1);
inb(0x84);
RTC_UNLOCK;
return (val);
}
static __inline void
writertc(u_char reg, u_char val)
{
RTC_LOCK;
inb(0x84);
outb(IO_RTC, reg);
inb(0x84);
outb(IO_RTC + 1, val);
inb(0x84); /* XXX work around wrong order in rtcin() */
RTC_UNLOCK;
}
static __inline int
readrtc(int port)
{
return(bcd2bin(rtcin(port)));
}
static u_int
calibrate_clocks(void)
{
u_int count, prev_count, tot_count;
int sec, start_sec, timeout;
if (bootverbose)
printf("Calibrating clock(s) ... ");
if (!(rtcin(RTC_STATUSD) & RTCSD_PWR))
goto fail;
timeout = 100000000;
/* Read the mc146818A seconds counter. */
for (;;) {
if (!(rtcin(RTC_STATUSA) & RTCSA_TUP)) {
sec = rtcin(RTC_SEC);
break;
}
if (--timeout == 0)
goto fail;
}
/* Wait for the mC146818A seconds counter to change. */
start_sec = sec;
for (;;) {
if (!(rtcin(RTC_STATUSA) & RTCSA_TUP)) {
sec = rtcin(RTC_SEC);
if (sec != start_sec)
break;
}
if (--timeout == 0)
goto fail;
}
/* Start keeping track of the i8254 counter. */
prev_count = getit();
if (prev_count == 0 || prev_count > timer0_max_count)
goto fail;
tot_count = 0;
/*
* Wait for the mc146818A seconds counter to change. Read the i8254
* counter for each iteration since this is convenient and only
* costs a few usec of inaccuracy. The timing of the final reads
* of the counters almost matches the timing of the initial reads,
* so the main cause of inaccuracy is the varying latency from
* inside getit() or rtcin(RTC_STATUSA) to the beginning of the
* rtcin(RTC_SEC) that returns a changed seconds count. The
* maximum inaccuracy from this cause is < 10 usec on 486's.
*/
start_sec = sec;
for (;;) {
if (!(rtcin(RTC_STATUSA) & RTCSA_TUP))
sec = rtcin(RTC_SEC);
count = getit();
if (count == 0 || count > timer0_max_count)
goto fail;
if (count > prev_count)
tot_count += prev_count - (count - timer0_max_count);
else
tot_count += prev_count - count;
prev_count = count;
if (sec != start_sec)
break;
if (--timeout == 0)
goto fail;
}
if (bootverbose) {
printf("i8254 clock: %u Hz\n", tot_count);
}
return (tot_count);
fail:
if (bootverbose)
printf("failed, using default i8254 clock of %u Hz\n",
timer_freq);
return (timer_freq);
}
static void
set_timer_freq(u_int freq, int intr_freq)
{
int new_timer0_real_max_count;
i8254_timecounter.tc_frequency = freq;
mtx_lock_spin(&clock_lock);
timer_freq = freq;
if (using_lapic_timer)
new_timer0_real_max_count = 0x10000;
else
new_timer0_real_max_count = TIMER_DIV(intr_freq);
if (new_timer0_real_max_count != timer0_real_max_count) {
timer0_real_max_count = new_timer0_real_max_count;
if (timer0_real_max_count == 0x10000)
timer0_max_count = 0xffff;
else
timer0_max_count = timer0_real_max_count;
outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
outb(TIMER_CNTR0, timer0_real_max_count & 0xff);
outb(TIMER_CNTR0, timer0_real_max_count >> 8);
}
mtx_unlock_spin(&clock_lock);
}
static void
i8254_restore(void)
{
mtx_lock_spin(&clock_lock);
outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
outb(TIMER_CNTR0, timer0_real_max_count & 0xff);
outb(TIMER_CNTR0, timer0_real_max_count >> 8);
mtx_unlock_spin(&clock_lock);
}
static void
rtc_restore(void)
{
/* Restore all of the RTC's "status" (actually, control) registers. */
/* XXX locking is needed for RTC access. */
writertc(RTC_STATUSB, RTCSB_24HR);
writertc(RTC_STATUSA, rtc_statusa);
writertc(RTC_STATUSB, rtc_statusb);
rtcin(RTC_INTR);
}
/*
* Restore all the timers non-atomically (XXX: should be atomically).
*
* This function is called from pmtimer_resume() to restore all the timers.
* This should not be necessary, but there are broken laptops that do not
* restore all the timers on resume.
*/
void
timer_restore(void)
{
i8254_restore(); /* restore timer_freq and hz */
rtc_restore(); /* reenable RTC interrupts */
}
/*
* Initialize 8254 timer 0 early so that it can be used in DELAY().
* XXX initialization of other timers is unintentionally left blank.
*/
void
startrtclock()
{
u_int delta, freq;
writertc(RTC_STATUSA, rtc_statusa);
writertc(RTC_STATUSB, RTCSB_24HR);
set_timer_freq(timer_freq, hz);
freq = calibrate_clocks();
#ifdef CLK_CALIBRATION_LOOP
if (bootverbose) {
printf(
"Press a key on the console to abort clock calibration\n");
while (cncheckc() == -1)
calibrate_clocks();
}
#endif
/*
* Use the calibrated i8254 frequency if it seems reasonable.
* Otherwise use the default, and don't use the calibrated i586
* frequency.
*/
delta = freq > timer_freq ? freq - timer_freq : timer_freq - freq;
if (delta < timer_freq / 100) {
#ifndef CLK_USE_I8254_CALIBRATION
if (bootverbose)
printf(
"CLK_USE_I8254_CALIBRATION not specified - using default frequency\n");
freq = timer_freq;
#endif
timer_freq = freq;
} else {
if (bootverbose)
printf(
"%d Hz differs from default of %d Hz by more than 1%%\n",
freq, timer_freq);
}
set_timer_freq(timer_freq, hz);
tc_init(&i8254_timecounter);
init_TSC();
}
/*
* Initialize the time of day register, based on the time base which is, e.g.
* from a filesystem.
*/
void
inittodr(time_t base)
{
unsigned long sec, days;
int year, month;
int y, m, s;
struct timespec ts;
if (base) {
s = splclock();
ts.tv_sec = base;
ts.tv_nsec = 0;
tc_setclock(&ts);
splx(s);
}
/* Look if we have a RTC present and the time is valid */
if (!(rtcin(RTC_STATUSD) & RTCSD_PWR))
goto wrong_time;
/* wait for time update to complete */
/* If RTCSA_TUP is zero, we have at least 244us before next update */
s = splhigh();
while (rtcin(RTC_STATUSA) & RTCSA_TUP) {
splx(s);
s = splhigh();
}
days = 0;
#ifdef USE_RTC_CENTURY
year = readrtc(RTC_YEAR) + readrtc(RTC_CENTURY) * 100;
#else
year = readrtc(RTC_YEAR) + 1900;
if (year < 1970)
year += 100;
#endif
if (year < 1970) {
splx(s);
goto wrong_time;
}
month = readrtc(RTC_MONTH);
for (m = 1; m < month; m++)
days += daysinmonth[m-1];
if ((month > 2) && LEAPYEAR(year))
days ++;
days += readrtc(RTC_DAY) - 1;
for (y = 1970; y < year; y++)
days += DAYSPERYEAR + LEAPYEAR(y);
sec = ((( days * 24 +
readrtc(RTC_HRS)) * 60 +
readrtc(RTC_MIN)) * 60 +
readrtc(RTC_SEC));
/* sec now contains the number of seconds, since Jan 1 1970,
in the local time zone */
sec += tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0);
y = time_second - sec;
if (y <= -2 || y >= 2) {
/* badly off, adjust it */
ts.tv_sec = sec;
ts.tv_nsec = 0;
tc_setclock(&ts);
}
splx(s);
return;
wrong_time:
printf("Invalid time in real time clock.\n");
printf("Check and reset the date immediately!\n");
}
/*
* Write system time back to RTC
*/
void
resettodr()
{
unsigned long tm;
int y, m, s;
if (disable_rtc_set)
return;
s = splclock();
tm = time_second;
splx(s);
/* Disable RTC updates and interrupts. */
writertc(RTC_STATUSB, RTCSB_HALT | RTCSB_24HR);
/* Calculate local time to put in RTC */
tm -= tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0);
writertc(RTC_SEC, bin2bcd(tm%60)); tm /= 60; /* Write back Seconds */
writertc(RTC_MIN, bin2bcd(tm%60)); tm /= 60; /* Write back Minutes */
writertc(RTC_HRS, bin2bcd(tm%24)); tm /= 24; /* Write back Hours */
/* We have now the days since 01-01-1970 in tm */
writertc(RTC_WDAY, (tm + 4) % 7 + 1); /* Write back Weekday */
for (y = 1970, m = DAYSPERYEAR + LEAPYEAR(y);
tm >= m;
y++, m = DAYSPERYEAR + LEAPYEAR(y))
tm -= m;
/* Now we have the years in y and the day-of-the-year in tm */
writertc(RTC_YEAR, bin2bcd(y%100)); /* Write back Year */
#ifdef USE_RTC_CENTURY
writertc(RTC_CENTURY, bin2bcd(y/100)); /* ... and Century */
#endif
for (m = 0; ; m++) {
int ml;
ml = daysinmonth[m];
if (m == 1 && LEAPYEAR(y))
ml++;
if (tm < ml)
break;
tm -= ml;
}
writertc(RTC_MONTH, bin2bcd(m + 1)); /* Write back Month */
writertc(RTC_DAY, bin2bcd(tm + 1)); /* Write back Month Day */
/* Reenable RTC updates and interrupts. */
writertc(RTC_STATUSB, rtc_statusb);
rtcin(RTC_INTR);
}
/*
* Start both clocks running.
*/
void
cpu_initclocks()
{
int diag;
#ifdef DEV_APIC
using_lapic_timer = lapic_setup_clock();
#endif
/*
* If we aren't using the local APIC timer to drive the kernel
* clocks, setup the interrupt handler for the 8254 timer 0 so
* that it can drive hardclock(). Otherwise, change the 8254
* timecounter to user a simpler algorithm.
*/
if (!using_lapic_timer) {
intr_add_handler("clk", 0, (driver_intr_t *)clkintr, NULL,
INTR_TYPE_CLK | INTR_FAST, NULL);
i8254_intsrc = intr_lookup_source(0);
if (i8254_intsrc != NULL)
i8254_pending =
i8254_intsrc->is_pic->pic_source_pending;
} else {
i8254_timecounter.tc_get_timecount =
i8254_simple_get_timecount;
i8254_timecounter.tc_counter_mask = 0xffff;
set_timer_freq(timer_freq, hz);
}
/* Initialize RTC. */
writertc(RTC_STATUSA, rtc_statusa);
writertc(RTC_STATUSB, RTCSB_24HR);
/*
* If the separate statistics clock hasn't been explicility disabled
* and we aren't already using the local APIC timer to drive the
* kernel clocks, then setup the RTC to periodically interrupt to
* drive statclock() and profclock().
*/
if (!statclock_disable && !using_lapic_timer) {
diag = rtcin(RTC_DIAG);
if (diag != 0)
printf("RTC BIOS diagnostic error %b\n", diag, RTCDG_BITS);
/* Setting stathz to nonzero early helps avoid races. */
stathz = RTC_NOPROFRATE;
profhz = RTC_PROFRATE;
/* Enable periodic interrupts from the RTC. */
rtc_statusb |= RTCSB_PINTR;
intr_add_handler("rtc", 8, (driver_intr_t *)rtcintr, NULL,
INTR_TYPE_CLK | INTR_FAST, NULL);
writertc(RTC_STATUSB, rtc_statusb);
rtcin(RTC_INTR);
}
init_TSC_tc();
}
void
cpu_startprofclock(void)
{
if (using_lapic_timer)
return;
rtc_statusa = RTCSA_DIVIDER | RTCSA_PROF;
writertc(RTC_STATUSA, rtc_statusa);
psdiv = pscnt = psratio;
}
void
cpu_stopprofclock(void)
{
if (using_lapic_timer)
return;
rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF;
writertc(RTC_STATUSA, rtc_statusa);
psdiv = pscnt = 1;
}
static int
sysctl_machdep_i8254_freq(SYSCTL_HANDLER_ARGS)
{
int error;
u_int freq;
/*
* Use `i8254' instead of `timer' in external names because `timer'
* is is too generic. Should use it everywhere.
*/
freq = timer_freq;
error = sysctl_handle_int(oidp, &freq, sizeof(freq), req);
if (error == 0 && req->newptr != NULL)
set_timer_freq(freq, hz);
return (error);
}
SYSCTL_PROC(_machdep, OID_AUTO, i8254_freq, CTLTYPE_INT | CTLFLAG_RW,
0, sizeof(u_int), sysctl_machdep_i8254_freq, "IU", "");
static unsigned
i8254_simple_get_timecount(struct timecounter *tc)
{
return (timer0_max_count - getit());
}
static unsigned
i8254_get_timecount(struct timecounter *tc)
{
u_int count;
u_int high, low;
u_int eflags;
eflags = read_eflags();
mtx_lock_spin(&clock_lock);
/* Select timer0 and latch counter value. */
outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
low = inb(TIMER_CNTR0);
high = inb(TIMER_CNTR0);
count = timer0_max_count - ((high << 8) | low);
if (count < i8254_lastcount ||
(!i8254_ticked && (clkintr_pending ||
((count < 20 || (!(eflags & PSL_I) && count < timer0_max_count / 2u)) &&
i8254_pending != NULL && i8254_pending(i8254_intsrc))))) {
i8254_ticked = 1;
i8254_offset += timer0_max_count;
}
i8254_lastcount = count;
count += i8254_offset;
mtx_unlock_spin(&clock_lock);
return (count);
}
#ifdef DEV_ISA
/*
* Attach to the ISA PnP descriptors for the timer and realtime clock.
*/
static struct isa_pnp_id attimer_ids[] = {
{ 0x0001d041 /* PNP0100 */, "AT timer" },
{ 0x000bd041 /* PNP0B00 */, "AT realtime clock" },
{ 0 }
};
static int
attimer_probe(device_t dev)
{
int result;
if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, attimer_ids)) <= 0)
device_quiet(dev);
return(result);
}
static int
attimer_attach(device_t dev)
{
return(0);
}
static device_method_t attimer_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, attimer_probe),
DEVMETHOD(device_attach, attimer_attach),
DEVMETHOD(device_detach, bus_generic_detach),
DEVMETHOD(device_shutdown, bus_generic_shutdown),
DEVMETHOD(device_suspend, bus_generic_suspend), /* XXX stop statclock? */
DEVMETHOD(device_resume, bus_generic_resume), /* XXX restart statclock? */
{ 0, 0 }
};
static driver_t attimer_driver = {
"attimer",
attimer_methods,
1, /* no softc */
};
static devclass_t attimer_devclass;
DRIVER_MODULE(attimer, isa, attimer_driver, attimer_devclass, 0, 0);
DRIVER_MODULE(attimer, acpi, attimer_driver, attimer_devclass, 0, 0);
#endif /* DEV_ISA */