927 lines
23 KiB
C
927 lines
23 KiB
C
/*-
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* Copyright (c) 1990 The Regents of the University of California.
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* All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* William Jolitz and Don Ahn.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* from: @(#)clock.c 7.2 (Berkeley) 5/12/91
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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/*
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* Routines to handle clock hardware.
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*/
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/*
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* inittodr, settodr and support routines written
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* by Christoph Robitschko <chmr@edvz.tu-graz.ac.at>
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*
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* reintroduced and updated by Chris Stenton <chris@gnome.co.uk> 8/10/94
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*/
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#include "opt_apic.h"
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#include "opt_clock.h"
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#include "opt_isa.h"
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#include "opt_mca.h"
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#include "opt_xbox.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/bus.h>
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#include <sys/clock.h>
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#include <sys/lock.h>
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#include <sys/kdb.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/time.h>
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#include <sys/timetc.h>
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#include <sys/kernel.h>
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#include <sys/limits.h>
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#include <sys/module.h>
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#include <sys/sched.h>
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#include <sys/sysctl.h>
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#include <sys/cons.h>
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#include <sys/power.h>
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#include <machine/clock.h>
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#include <machine/cpu.h>
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#include <machine/cputypes.h>
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#include <machine/frame.h>
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#include <machine/intr_machdep.h>
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#include <machine/md_var.h>
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#include <machine/psl.h>
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#ifdef DEV_APIC
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#include <machine/apicvar.h>
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#endif
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#include <machine/specialreg.h>
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#include <machine/ppireg.h>
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#include <machine/timerreg.h>
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#include <isa/rtc.h>
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#ifdef DEV_ISA
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#include <isa/isareg.h>
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#include <isa/isavar.h>
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#endif
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#ifdef DEV_MCA
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#include <i386/bios/mca_machdep.h>
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#endif
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#define TIMER_DIV(x) ((timer_freq + (x) / 2) / (x))
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int clkintr_pending;
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int pscnt = 1;
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int psdiv = 1;
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int statclock_disable;
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#ifndef TIMER_FREQ
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#define TIMER_FREQ 1193182
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#endif
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u_int timer_freq = TIMER_FREQ;
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int timer0_max_count;
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int timer0_real_max_count;
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struct mtx clock_lock;
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#define RTC_LOCK mtx_lock_spin(&clock_lock)
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#define RTC_UNLOCK mtx_unlock_spin(&clock_lock)
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static int beeping = 0;
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static struct intsrc *i8254_intsrc;
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static u_int32_t i8254_lastcount;
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static u_int32_t i8254_offset;
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static int (*i8254_pending)(struct intsrc *);
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static int i8254_ticked;
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static int using_lapic_timer;
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static u_char rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF;
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static u_char rtc_statusb = RTCSB_24HR;
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/* Values for timerX_state: */
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#define RELEASED 0
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#define RELEASE_PENDING 1
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#define ACQUIRED 2
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#define ACQUIRE_PENDING 3
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static u_char timer2_state;
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static unsigned i8254_get_timecount(struct timecounter *tc);
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static unsigned i8254_simple_get_timecount(struct timecounter *tc);
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static void set_timer_freq(u_int freq, int intr_freq);
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static struct timecounter i8254_timecounter = {
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i8254_get_timecount, /* get_timecount */
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0, /* no poll_pps */
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~0u, /* counter_mask */
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0, /* frequency */
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"i8254", /* name */
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0 /* quality */
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};
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static void
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clkintr(struct trapframe *frame)
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{
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if (timecounter->tc_get_timecount == i8254_get_timecount) {
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mtx_lock_spin(&clock_lock);
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if (i8254_ticked)
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i8254_ticked = 0;
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else {
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i8254_offset += timer0_max_count;
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i8254_lastcount = 0;
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}
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clkintr_pending = 0;
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mtx_unlock_spin(&clock_lock);
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}
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KASSERT(!using_lapic_timer, ("clk interrupt enabled with lapic timer"));
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hardclock(TRAPF_USERMODE(frame), TRAPF_PC(frame));
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#ifdef DEV_MCA
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/* Reset clock interrupt by asserting bit 7 of port 0x61 */
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if (MCA_system)
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outb(0x61, inb(0x61) | 0x80);
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#endif
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}
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int
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acquire_timer2(int mode)
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{
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if (timer2_state != RELEASED)
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return (-1);
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timer2_state = ACQUIRED;
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/*
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* This access to the timer registers is as atomic as possible
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* because it is a single instruction. We could do better if we
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* knew the rate. Use of splclock() limits glitches to 10-100us,
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* and this is probably good enough for timer2, so we aren't as
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* careful with it as with timer0.
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*/
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outb(TIMER_MODE, TIMER_SEL2 | (mode & 0x3f));
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return (0);
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}
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int
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release_timer2()
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{
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if (timer2_state != ACQUIRED)
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return (-1);
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timer2_state = RELEASED;
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outb(TIMER_MODE, TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT);
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return (0);
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}
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/*
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* This routine receives statistical clock interrupts from the RTC.
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* As explained above, these occur at 128 interrupts per second.
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* When profiling, we receive interrupts at a rate of 1024 Hz.
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*
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* This does not actually add as much overhead as it sounds, because
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* when the statistical clock is active, the hardclock driver no longer
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* needs to keep (inaccurate) statistics on its own. This decouples
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* statistics gathering from scheduling interrupts.
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*
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* The RTC chip requires that we read status register C (RTC_INTR)
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* to acknowledge an interrupt, before it will generate the next one.
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* Under high interrupt load, rtcintr() can be indefinitely delayed and
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* the clock can tick immediately after the read from RTC_INTR. In this
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* case, the mc146818A interrupt signal will not drop for long enough
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* to register with the 8259 PIC. If an interrupt is missed, the stat
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* clock will halt, considerably degrading system performance. This is
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* why we use 'while' rather than a more straightforward 'if' below.
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* Stat clock ticks can still be lost, causing minor loss of accuracy
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* in the statistics, but the stat clock will no longer stop.
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*/
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static void
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rtcintr(struct trapframe *frame)
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{
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while (rtcin(RTC_INTR) & RTCIR_PERIOD) {
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if (profprocs != 0) {
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if (--pscnt == 0)
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pscnt = psdiv;
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profclock(TRAPF_USERMODE(frame), TRAPF_PC(frame));
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}
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if (pscnt == psdiv)
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statclock(TRAPF_USERMODE(frame));
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}
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}
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#include "opt_ddb.h"
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#ifdef DDB
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#include <ddb/ddb.h>
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DB_SHOW_COMMAND(rtc, rtc)
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{
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printf("%02x/%02x/%02x %02x:%02x:%02x, A = %02x, B = %02x, C = %02x\n",
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rtcin(RTC_YEAR), rtcin(RTC_MONTH), rtcin(RTC_DAY),
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rtcin(RTC_HRS), rtcin(RTC_MIN), rtcin(RTC_SEC),
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rtcin(RTC_STATUSA), rtcin(RTC_STATUSB), rtcin(RTC_INTR));
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}
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#endif /* DDB */
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static int
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getit(void)
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{
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int high, low;
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mtx_lock_spin(&clock_lock);
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/* Select timer0 and latch counter value. */
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outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
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low = inb(TIMER_CNTR0);
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high = inb(TIMER_CNTR0);
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mtx_unlock_spin(&clock_lock);
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return ((high << 8) | low);
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}
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/*
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* Wait "n" microseconds.
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* Relies on timer 1 counting down from (timer_freq / hz)
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* Note: timer had better have been programmed before this is first used!
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*/
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void
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DELAY(int n)
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{
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int delta, prev_tick, tick, ticks_left;
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#ifdef DELAYDEBUG
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int getit_calls = 1;
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int n1;
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static int state = 0;
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#endif
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if (tsc_freq != 0 && !tsc_is_broken) {
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uint64_t start, end, now;
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sched_pin();
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start = rdtsc();
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end = start + (tsc_freq * n) / 1000000;
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do {
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now = rdtsc();
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} while (now < end || (now > start && end < start));
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sched_unpin();
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return;
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}
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#ifdef DELAYDEBUG
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if (state == 0) {
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state = 1;
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for (n1 = 1; n1 <= 10000000; n1 *= 10)
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DELAY(n1);
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state = 2;
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}
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if (state == 1)
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printf("DELAY(%d)...", n);
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#endif
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/*
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* Guard against the timer being uninitialized if we are called
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* early for console i/o.
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*/
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if (timer0_max_count == 0)
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set_timer_freq(timer_freq, hz);
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/*
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* Read the counter first, so that the rest of the setup overhead is
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* counted. Guess the initial overhead is 20 usec (on most systems it
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* takes about 1.5 usec for each of the i/o's in getit(). The loop
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* takes about 6 usec on a 486/33 and 13 usec on a 386/20. The
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* multiplications and divisions to scale the count take a while).
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*
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* However, if ddb is active then use a fake counter since reading
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* the i8254 counter involves acquiring a lock. ddb must not do
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* locking for many reasons, but it calls here for at least atkbd
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* input.
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*/
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#ifdef KDB
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if (kdb_active)
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prev_tick = 1;
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else
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#endif
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prev_tick = getit();
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n -= 0; /* XXX actually guess no initial overhead */
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/*
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* Calculate (n * (timer_freq / 1e6)) without using floating point
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* and without any avoidable overflows.
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*/
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if (n <= 0)
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ticks_left = 0;
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else if (n < 256)
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/*
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* Use fixed point to avoid a slow division by 1000000.
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* 39099 = 1193182 * 2^15 / 10^6 rounded to nearest.
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* 2^15 is the first power of 2 that gives exact results
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* for n between 0 and 256.
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*/
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ticks_left = ((u_int)n * 39099 + (1 << 15) - 1) >> 15;
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else
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/*
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* Don't bother using fixed point, although gcc-2.7.2
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* generates particularly poor code for the long long
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* division, since even the slow way will complete long
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* before the delay is up (unless we're interrupted).
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*/
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ticks_left = ((u_int)n * (long long)timer_freq + 999999)
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/ 1000000;
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while (ticks_left > 0) {
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#ifdef KDB
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if (kdb_active) {
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inb(0x84);
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tick = prev_tick - 1;
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if (tick <= 0)
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tick = timer0_max_count;
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} else
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#endif
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tick = getit();
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#ifdef DELAYDEBUG
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++getit_calls;
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#endif
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delta = prev_tick - tick;
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prev_tick = tick;
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if (delta < 0) {
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delta += timer0_max_count;
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/*
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* Guard against timer0_max_count being wrong.
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* This shouldn't happen in normal operation,
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* but it may happen if set_timer_freq() is
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* traced.
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*/
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if (delta < 0)
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delta = 0;
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}
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ticks_left -= delta;
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}
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#ifdef DELAYDEBUG
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if (state == 1)
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printf(" %d calls to getit() at %d usec each\n",
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getit_calls, (n + 5) / getit_calls);
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#endif
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}
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static void
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sysbeepstop(void *chan)
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{
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ppi_spkr_off(); /* disable counter2 output to speaker */
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timer_spkr_release();
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beeping = 0;
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}
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int
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sysbeep(int pitch, int period)
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{
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int x = splclock();
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if (timer_spkr_acquire())
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if (!beeping) {
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/* Something else owns it. */
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splx(x);
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return (-1); /* XXX Should be EBUSY, but nobody cares anyway. */
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}
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mtx_lock_spin(&clock_lock);
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spkr_set_pitch(pitch);
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mtx_unlock_spin(&clock_lock);
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if (!beeping) {
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/* enable counter2 output to speaker */
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ppi_spkr_on();
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beeping = period;
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timeout(sysbeepstop, (void *)NULL, period);
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}
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splx(x);
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return (0);
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}
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|
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/*
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* RTC support routines
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*/
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int
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rtcin(reg)
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int reg;
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{
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u_char val;
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RTC_LOCK;
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outb(IO_RTC, reg);
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inb(0x84);
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val = inb(IO_RTC + 1);
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inb(0x84);
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RTC_UNLOCK;
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return (val);
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}
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static __inline void
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writertc(u_char reg, u_char val)
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{
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RTC_LOCK;
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inb(0x84);
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outb(IO_RTC, reg);
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inb(0x84);
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outb(IO_RTC + 1, val);
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inb(0x84); /* XXX work around wrong order in rtcin() */
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RTC_UNLOCK;
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}
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|
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static __inline int
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readrtc(int port)
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{
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return(bcd2bin(rtcin(port)));
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}
|
|
|
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static u_int
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calibrate_clocks(void)
|
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{
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u_int count, prev_count, tot_count;
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int sec, start_sec, timeout;
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|
|
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if (bootverbose)
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printf("Calibrating clock(s) ... ");
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if (!(rtcin(RTC_STATUSD) & RTCSD_PWR))
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goto fail;
|
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timeout = 100000000;
|
|
|
|
/* Read the mc146818A seconds counter. */
|
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for (;;) {
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if (!(rtcin(RTC_STATUSA) & RTCSA_TUP)) {
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sec = rtcin(RTC_SEC);
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break;
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}
|
|
if (--timeout == 0)
|
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goto fail;
|
|
}
|
|
|
|
/* Wait for the mC146818A seconds counter to change. */
|
|
start_sec = sec;
|
|
for (;;) {
|
|
if (!(rtcin(RTC_STATUSA) & RTCSA_TUP)) {
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sec = rtcin(RTC_SEC);
|
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if (sec != start_sec)
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break;
|
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}
|
|
if (--timeout == 0)
|
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goto fail;
|
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}
|
|
|
|
/* Start keeping track of the i8254 counter. */
|
|
prev_count = getit();
|
|
if (prev_count == 0 || prev_count > timer0_max_count)
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goto fail;
|
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tot_count = 0;
|
|
|
|
/*
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|
* 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
|
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* 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;
|
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for (;;) {
|
|
if (!(rtcin(RTC_STATUSA) & RTCSA_TUP))
|
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sec = rtcin(RTC_SEC);
|
|
count = getit();
|
|
if (count == 0 || count > timer0_max_count)
|
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goto fail;
|
|
if (count > prev_count)
|
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tot_count += prev_count - (count - timer0_max_count);
|
|
else
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|
tot_count += prev_count - count;
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|
prev_count = count;
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if (sec != start_sec)
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break;
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|
if (--timeout == 0)
|
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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)
|
|
{
|
|
int s;
|
|
struct timespec ts;
|
|
struct clocktime ct;
|
|
|
|
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)) {
|
|
printf("Invalid time in real time clock.\n");
|
|
printf("Check and reset the date immediately!\n");
|
|
return;
|
|
}
|
|
|
|
/* 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();
|
|
}
|
|
ct.nsec = 0;
|
|
ct.sec = readrtc(RTC_SEC);
|
|
ct.min = readrtc(RTC_MIN);
|
|
ct.hour = readrtc(RTC_HRS);
|
|
ct.day = readrtc(RTC_DAY);
|
|
ct.dow = readrtc(RTC_WDAY) - 1;
|
|
ct.mon = readrtc(RTC_MONTH);
|
|
ct.year = readrtc(RTC_YEAR);
|
|
#ifdef USE_RTC_CENTURY
|
|
ct.year += readrtc(RTC_CENTURY) * 100;
|
|
#else
|
|
ct.year += 2000;
|
|
#endif
|
|
clock_ct_to_ts(&ct, &ts);
|
|
ts.tv_sec += utc_offset();
|
|
tc_setclock(&ts);
|
|
}
|
|
|
|
/*
|
|
* Write system time back to RTC
|
|
*/
|
|
void
|
|
resettodr()
|
|
{
|
|
struct timespec ts;
|
|
struct clocktime ct;
|
|
|
|
if (disable_rtc_set)
|
|
return;
|
|
|
|
getnanotime(&ts);
|
|
ts.tv_sec -= utc_offset();
|
|
clock_ts_to_ct(&ts, &ct);
|
|
|
|
/* Disable RTC updates and interrupts. */
|
|
writertc(RTC_STATUSB, RTCSB_HALT | RTCSB_24HR);
|
|
|
|
writertc(RTC_SEC, bin2bcd(ct.sec)); /* Write back Seconds */
|
|
writertc(RTC_MIN, bin2bcd(ct.min)); /* Write back Minutes */
|
|
writertc(RTC_HRS, bin2bcd(ct.hour)); /* Write back Hours */
|
|
|
|
writertc(RTC_WDAY, ct.dow + 1); /* Write back Weekday */
|
|
writertc(RTC_DAY, bin2bcd(ct.day)); /* Write back Day */
|
|
writertc(RTC_MONTH, bin2bcd(ct.mon)); /* Write back Month */
|
|
writertc(RTC_YEAR, bin2bcd(ct.year % 100)); /* Write back Year */
|
|
#ifdef USE_RTC_CENTURY
|
|
writertc(RTC_CENTURY, bin2bcd(ct.year / 100)); /* ... and Century */
|
|
#endif
|
|
|
|
/* 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 */
|