diff options
author | phk <phk@FreeBSD.org> | 2008-04-14 07:57:15 +0000 |
---|---|---|
committer | phk <phk@FreeBSD.org> | 2008-04-14 07:57:15 +0000 |
commit | 0f73a35e529f06e0336161a85c45b7579e92f2b3 (patch) | |
tree | 450f845347a839c23ddd6a2d6910af54aeef98e5 /sys | |
parent | 9d72a61c728bf62182ed20abef4a8463f15d817e (diff) | |
download | FreeBSD-src-0f73a35e529f06e0336161a85c45b7579e92f2b3.zip FreeBSD-src-0f73a35e529f06e0336161a85c45b7579e92f2b3.tar.gz |
atrtc.c is a repocopy of the RTC device driver from i386/isa/clock.c
In addition to the device driver functionality, it exposes a number of
functions which various other bits of code use to fondle the RTC chip.
Diffstat (limited to 'sys')
-rw-r--r-- | sys/isa/atrtc.c | 628 | ||||
-rw-r--r-- | sys/isa/rtc.h | 11 |
2 files changed, 40 insertions, 599 deletions
diff --git a/sys/isa/atrtc.c b/sys/isa/atrtc.c index 6573b37..87d03a5 100644 --- a/sys/isa/atrtc.c +++ b/sys/isa/atrtc.c @@ -1,10 +1,7 @@ /*- - * Copyright (c) 1990 The Regents of the University of California. + * Copyright (c) 2008 Poul-Henning Kamp * 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: @@ -13,14 +10,11 @@ * 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 + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR 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) @@ -29,53 +23,22 @@ * 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 + * $FreeBSD$ */ #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 "opt_xbox.h" #include <sys/param.h> #include <sys/systm.h> #include <sys/bus.h> #include <sys/clock.h> #include <sys/lock.h> -#include <sys/kdb.h> #include <sys/mutex.h> -#include <sys/proc.h> -#include <sys/timetc.h> #include <sys/kernel.h> #include <sys/module.h> -#include <sys/sched.h> -#include <sys/sysctl.h> - -#include <machine/clock.h> -#include <machine/cpu.h> -#include <machine/frame.h> -#include <machine/intr_machdep.h> -#include <machine/md_var.h> -#ifdef DEV_APIC -#include <machine/apicvar.h> -#endif -#include <machine/ppireg.h> -#include <machine/timerreg.h> #include <isa/rtc.h> #ifdef DEV_ISA @@ -83,313 +46,13 @@ __FBSDID("$FreeBSD$"); #include <isa/isavar.h> #endif -#ifdef DEV_MCA -#include <i386/bios/mca_machdep.h> -#endif - -#define TIMER_DIV(x) ((i8254_freq + (x) / 2) / (x)) - -int clkintr_pending; -static int pscnt = 1; -static int psdiv = 1; -int statclock_disable; -#ifndef TIMER_FREQ -#define TIMER_FREQ 1193182 -#endif -u_int i8254_freq = TIMER_FREQ; -TUNABLE_INT("hw.i8254.freq", &i8254_freq); -int i8254_max_count; -static int i8254_real_max_count; #define RTC_LOCK mtx_lock_spin(&clock_lock) #define RTC_UNLOCK mtx_unlock_spin(&clock_lock) -static struct mtx clock_lock; -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 int rtc_reg = -1; 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_i8254_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 int -clkintr(struct trapframe *frame) -{ - - if (timecounter->tc_get_timecount == i8254_get_timecount) { - mtx_lock_spin(&clock_lock); - if (i8254_ticked) - i8254_ticked = 0; - else { - i8254_offset += i8254_max_count; - i8254_lastcount = 0; - } - clkintr_pending = 0; - mtx_unlock_spin(&clock_lock); - } - KASSERT(!using_lapic_timer, ("clk interrupt enabled with lapic timer")); - hardclock(TRAPF_USERMODE(frame), TRAPF_PC(frame)); -#ifdef DEV_MCA - /* Reset clock interrupt by asserting bit 7 of port 0x61 */ - if (MCA_system) - outb(0x61, inb(0x61) | 0x80); -#endif - return (FILTER_HANDLED); -} - -int -timer_spkr_acquire(void) -{ - int mode; - - mode = TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT; - - 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)); - ppi_spkr_on(); /* enable counter2 output to speaker */ - return (0); -} - -int -timer_spkr_release(void) -{ - - if (timer2_state != ACQUIRED) - return (-1); - timer2_state = RELEASED; - outb(TIMER_MODE, TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT); - ppi_spkr_off(); /* disable counter2 output to speaker */ - return (0); -} - -void -timer_spkr_setfreq(int freq) -{ - - freq = i8254_freq / freq; - mtx_lock_spin(&clock_lock); - outb(TIMER_CNTR2, freq & 0xff); - outb(TIMER_CNTR2, freq >> 8); - mtx_unlock_spin(&clock_lock); -} - -/* - * 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 int -rtcintr(struct trapframe *frame) -{ - - while (rtcin(RTC_INTR) & RTCIR_PERIOD) { - if (profprocs != 0) { - if (--pscnt == 0) - pscnt = psdiv; - profclock(TRAPF_USERMODE(frame), TRAPF_PC(frame)); - } - if (pscnt == psdiv) - statclock(TRAPF_USERMODE(frame)); - } - return (FILTER_HANDLED); -} - -#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 (i8254_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; -#endif - - if (tsc_freq != 0 && !tsc_is_broken) { - uint64_t start, end, now; - - sched_pin(); - start = rdtsc(); - end = start + (tsc_freq * n) / 1000000; - do { - cpu_spinwait(); - now = rdtsc(); - } while (now < end || (now > start && end < start)); - sched_unpin(); - return; - } -#ifdef DELAYDEBUG - if (state == 0) { - state = 1; - for (n1 = 1; n1 <= 10000000; n1 *= 10) - DELAY(n1); - state = 2; - } - if (state == 1) - printf("DELAY(%d)...", n); -#endif - /* - * 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 * (i8254_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)i8254_freq + 999999) - / 1000000; - - while (ticks_left > 0) { -#ifdef KDB - if (kdb_active) { - inb(0x84); - tick = prev_tick - 1; - if (tick <= 0) - tick = i8254_max_count; - } else -#endif - tick = getit(); -#ifdef DELAYDEBUG - ++getit_calls; -#endif - delta = prev_tick - tick; - prev_tick = tick; - if (delta < 0) { - delta += i8254_max_count; - /* - * Guard against i8254_max_count being wrong. - * This shouldn't happen in normal operation, - * but it may happen if set_i8254_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 -} - /* * RTC support routines */ @@ -433,287 +96,43 @@ readrtc(int port) return(bcd2bin(rtcin(port))); } -static void -set_i8254_freq(u_int freq, int intr_freq) -{ - int new_i8254_real_max_count; - - i8254_timecounter.tc_frequency = freq; - mtx_lock_spin(&clock_lock); - i8254_freq = freq; - if (using_lapic_timer) - new_i8254_real_max_count = 0x10000; - else - new_i8254_real_max_count = TIMER_DIV(intr_freq); - if (new_i8254_real_max_count != i8254_real_max_count) { - i8254_real_max_count = new_i8254_real_max_count; - if (i8254_real_max_count == 0x10000) - i8254_max_count = 0xffff; - else - i8254_max_count = i8254_real_max_count; - outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT); - outb(TIMER_CNTR0, i8254_real_max_count & 0xff); - outb(TIMER_CNTR0, i8254_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, i8254_real_max_count & 0xff); - outb(TIMER_CNTR0, i8254_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. */ - rtc_reg = -1; - 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 i8254_freq and hz */ - rtc_restore(); /* reenable RTC interrupts */ -} - -/* This is separate from startrtclock() so that it can be called early. */ -void -i8254_init(void) -{ - - mtx_init(&clock_lock, "clk", NULL, MTX_SPIN | MTX_NOPROFILE); - set_i8254_freq(i8254_freq, hz); -} - -void -startrtclock() +atrtc_start(void) { writertc(RTC_STATUSA, rtc_statusa); writertc(RTC_STATUSB, RTCSB_24HR); - - set_i8254_freq(i8254_freq, hz); - tc_init(&i8254_timecounter); - - init_TSC(); } -/* - * Start both clocks running. - */ void -cpu_initclocks() +atrtc_rate(unsigned rate) { - 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_filter_t *)clkintr, NULL, - NULL, INTR_TYPE_CLK, 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_i8254_freq(i8254_freq, hz); - } - - /* Initialize RTC. */ + rtc_statusa = RTCSA_DIVIDER | rate; 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_filter_t *)rtcintr, NULL, NULL, - INTR_TYPE_CLK, NULL); - - writertc(RTC_STATUSB, rtc_statusb); - rtcin(RTC_INTR); - } - - init_TSC_tc(); } void -cpu_startprofclock(void) +atrtc_enable_intr(void) { - if (using_lapic_timer) - return; - rtc_statusa = RTCSA_DIVIDER | RTCSA_PROF; - writertc(RTC_STATUSA, rtc_statusa); - psdiv = pscnt = psratio; + rtc_statusb |= RTCSB_PINTR; + writertc(RTC_STATUSB, rtc_statusb); + rtcin(RTC_INTR); } void -cpu_stopprofclock(void) +atrtc_restore(void) { - if (using_lapic_timer) - return; - rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF; + /* Restore all of the RTC's "status" (actually, control) registers. */ + rtcin(RTC_STATUSA); /* dummy to get rtc_reg set */ + writertc(RTC_STATUSB, RTCSB_24HR); 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 = i8254_freq; - error = sysctl_handle_int(oidp, &freq, 0, req); - if (error == 0 && req->newptr != NULL) - set_i8254_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 (i8254_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 = i8254_max_count - ((high << 8) | low); - if (count < i8254_lastcount || - (!i8254_ticked && (clkintr_pending || - ((count < 20 || (!(eflags & PSL_I) && - count < i8254_max_count / 2u)) && - i8254_pending != NULL && i8254_pending(i8254_intsrc))))) { - i8254_ticked = 1; - i8254_offset += i8254_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 - */ -static struct isa_pnp_id attimer_ids[] = { - { 0x0001d041 /* PNP0100 */, "AT timer" }, - { 0 } -}; - -static int -attimer_probe(device_t dev) -{ - int result; - - result = ISA_PNP_PROBE(device_get_parent(dev), dev, attimer_ids); - if (result <= 0) - device_quiet(dev); - return(result); -} - -static int -attimer_attach(device_t dev) -{ - return(0); + writertc(RTC_STATUSB, rtc_statusb); + rtcin(RTC_INTR); } -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), - DEVMETHOD(device_resume, bus_generic_resume), - { 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 */ - -#ifdef DEV_ISA - /********************************************************************** * RTC driver for subr_rtc */ @@ -866,4 +285,15 @@ static devclass_t atrtc_devclass; DRIVER_MODULE(atrtc, isa, atrtc_driver, atrtc_devclass, 0, 0); DRIVER_MODULE(atrtc, acpi, atrtc_driver, atrtc_devclass, 0, 0); -#endif /* DEV_ISA */ +#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 */ diff --git a/sys/isa/rtc.h b/sys/isa/rtc.h index 35bef94..c802b0b 100644 --- a/sys/isa/rtc.h +++ b/sys/isa/rtc.h @@ -110,4 +110,15 @@ #define RTC_EXTHI 0x18 /* low byte of extended mem size */ #define RTC_CENTURY 0x32 /* current century */ + +#ifdef _KERNEL +extern struct mtx clock_lock; +int rtcin(int reg); +void atrtc_start(void); +void atrtc_rate(unsigned rate); +void atrtc_enable_intr(void); +void atrtc_restore(void); +void writertc(int reg, u_char val); +#endif + #endif /* _I386_ISA_RTC_H_ */ |