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Diffstat (limited to 'arch/ppc/kernel/time.c')
| -rw-r--r-- | arch/ppc/kernel/time.c | 465 |
1 files changed, 0 insertions, 465 deletions
diff --git a/arch/ppc/kernel/time.c b/arch/ppc/kernel/time.c index cdcad8204..e69de29bb 100644 --- a/arch/ppc/kernel/time.c +++ b/arch/ppc/kernel/time.c @@ -1,465 +0,0 @@ -/* - * linux/arch/i386/kernel/time.c - * - * Copyright (C) 1991, 1992, 1995 Linus Torvalds - * - * Adapted for PowerPC (PreP) by Gary Thomas - * - * This file contains the PC-specific time handling details: - * reading the RTC at bootup, etc.. - * 1994-07-02 Alan Modra - * fixed set_rtc_mmss, fixed time.year for >= 2000, new mktime - * 1995-03-26 Markus Kuhn - * fixed 500 ms bug at call to set_rtc_mmss, fixed DS12887 - * precision CMOS clock update - */ -#include <linux/errno.h> -#include <linux/sched.h> -#include <linux/kernel.h> -#include <linux/param.h> -#include <linux/string.h> -#include <linux/mm.h> - -#include <asm/segment.h> -#include <asm/io.h> -#include <asm/nvram.h> -#include <asm/mc146818rtc.h> -#include <asm/processor.h> - -#include <linux/timex.h> -#include <linux/config.h> - -extern int isBeBox[]; - -#define TIMER_IRQ 0 - -/* Cycle counter value at the previous timer interrupt.. */ -static unsigned long long last_timer_cc = 0; -static unsigned long long init_timer_cc = 0; - -static inline int CMOS_READ(int addr) -{ - outb(addr>>8, NVRAM_AS1); - outb(addr, NVRAM_AS0); - return (inb(NVRAM_DATA)); -} - -static inline int CMOS_WRITE(int addr, int val) -{ - outb(addr>>8, NVRAM_AS1); - outb(addr, NVRAM_AS0); - return (outb(val, NVRAM_DATA)); -} - -/* This function must be called with interrupts disabled - * It was inspired by Steve McCanne's microtime-i386 for BSD. -- jrs - * - * However, the pc-audio speaker driver changes the divisor so that - * it gets interrupted rather more often - it loads 64 into the - * counter rather than 11932! This has an adverse impact on - * do_gettimeoffset() -- it stops working! What is also not - * good is that the interval that our timer function gets called - * is no longer 10.0002 ms, but 9.9767 ms. To get around this - * would require using a different timing source. Maybe someone - * could use the RTC - I know that this can interrupt at frequencies - * ranging from 8192Hz to 2Hz. If I had the energy, I'd somehow fix - * it so that at startup, the timer code in sched.c would select - * using either the RTC or the 8253 timer. The decision would be - * based on whether there was any other device around that needed - * to trample on the 8253. I'd set up the RTC to interrupt at 1024 Hz, - * and then do some jiggery to have a version of do_timer that - * advanced the clock by 1/1024 s. Every time that reached over 1/100 - * of a second, then do all the old code. If the time was kept correct - * then do_gettimeoffset could just return 0 - there is no low order - * divider that can be accessed. - * - * Ideally, you would be able to use the RTC for the speaker driver, - * but it appears that the speaker driver really needs interrupt more - * often than every 120 us or so. - * - * Anyway, this needs more thought.... pjsg (1993-08-28) - * - * If you are really that interested, you should be reading - * comp.protocols.time.ntp! - */ - -#define TICK_SIZE tick - -static unsigned long do_slow_gettimeoffset(void) -{ - int count; - unsigned long offset = 0; - - /* timer count may underflow right here */ - outb_p(0x00, 0x43); /* latch the count ASAP */ - count = inb_p(0x40); /* read the latched count */ - count |= inb(0x40) << 8; - /* we know probability of underflow is always MUCH less than 1% */ - if (count > (LATCH - LATCH/100)) { - /* check for pending timer interrupt */ - outb_p(0x0a, 0x20); - if (inb(0x20) & 1) - offset = TICK_SIZE; - } - count = ((LATCH-1) - count) * TICK_SIZE; - count = (count + LATCH/2) / LATCH; - return offset + count; -} - -static unsigned long (*do_gettimeoffset)(void) = do_slow_gettimeoffset; - -/* - * This version of gettimeofday has near microsecond resolution. - */ -void do_gettimeofday(struct timeval *tv) -{ - unsigned long flags; - - save_flags(flags); - cli(); - *tv = xtime; - tv->tv_usec += do_gettimeoffset(); - if (tv->tv_usec >= 1000000) { - tv->tv_usec -= 1000000; - tv->tv_sec++; - } - restore_flags(flags); -} - -void do_settimeofday(struct timeval *tv) -{ - cli(); - /* This is revolting. We need to set the xtime.tv_usec - * correctly. However, the value in this location is - * is value at the last tick. - * Discover what correction gettimeofday - * would have done, and then undo it! - */ - tv->tv_usec -= do_gettimeoffset(); - - if (tv->tv_usec < 0) { - tv->tv_usec += 1000000; - tv->tv_sec--; - } - - xtime = *tv; - time_state = TIME_BAD; - time_maxerror = 0x70000000; - time_esterror = 0x70000000; - set_rtc(xtime.tv_sec); - sti(); -} - -static int month_days[12] = { - 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 -}; - -#define FEBRUARY 2 -#define STARTOFTIME 1970 -#define SECDAY 86400L -#define SECYR (SECDAY * 365) -#define leapyear(year) ((year) % 4 == 0) -#define days_in_year(a) (leapyear(a) ? 366 : 365) -#define days_in_month(a) (month_days[(a) - 1]) - -struct _tm -{ - int tm_sec; - int tm_min; - int tm_hour; - int tm_day; - int tm_month; - int tm_year; -}; - -static _to_tm(int tim, struct _tm * tm) -{ - register int i; - register long hms, day; - - day = tim / SECDAY; - hms = tim % SECDAY; - - /* Hours, minutes, seconds are easy */ - tm->tm_hour = hms / 3600; - tm->tm_min = (hms % 3600) / 60; - tm->tm_sec = (hms % 3600) % 60; - - /* Number of years in days */ - for (i = STARTOFTIME; day >= days_in_year(i); i++) - day -= days_in_year(i); - tm->tm_year = i; - - /* Number of months in days left */ - if (leapyear(tm->tm_year)) - days_in_month(FEBRUARY) = 29; - for (i = 1; day >= days_in_month(i); i++) - day -= days_in_month(i); - days_in_month(FEBRUARY) = 28; - tm->tm_month = i; - - /* Days are what is left over (+1) from all that. */ - tm->tm_day = day + 1; -} - -/* - * Set the time into the CMOS - */ -static void set_rtc(unsigned long nowtime) -{ - int retval = 0; - struct _tm tm; - unsigned char save_control, save_freq_select; - - /*if (_Processor != _PROC_IBM) return;*/ - - _to_tm(nowtime, &tm); - - /* tell the clock it's being set */ - save_control = CMOS_MCRTC_READ(MCRTC_CONTROL); - CMOS_MCRTC_WRITE((save_control|MCRTC_SET), MCRTC_CONTROL); - /* stop and reset prescaler */ - save_freq_select = CMOS_MCRTC_READ(MCRTC_FREQ_SELECT); - CMOS_MCRTC_WRITE((save_freq_select|MCRTC_DIV_RESET2), MCRTC_FREQ_SELECT); - - printk("Set RTC H:M:S M/D/Y %d:%02d:%02d %d/%d/%d\n", - tm.tm_hour, tm.tm_min, tm.tm_sec, tm.tm_month, tm.tm_day, tm.tm_year); - if (!(save_control & MCRTC_DM_BINARY) || MCRTC_ALWAYS_BCD) { - BIN_TO_BCD(tm.tm_sec); - BIN_TO_BCD(tm.tm_min); - BIN_TO_BCD(tm.tm_hour); - BIN_TO_BCD(tm.tm_month); - BIN_TO_BCD(tm.tm_day); - BIN_TO_BCD(tm.tm_year); - } - - CMOS_MCRTC_WRITE(tm.tm_sec, MCRTC_SECONDS); - CMOS_MCRTC_WRITE(tm.tm_min, MCRTC_MINUTES); - CMOS_MCRTC_WRITE(tm.tm_hour, MCRTC_HOURS); - CMOS_MCRTC_WRITE(tm.tm_month, MCRTC_MONTH); - CMOS_MCRTC_WRITE(tm.tm_day, MCRTC_MINUTES); - CMOS_MCRTC_WRITE(tm.tm_year - 1900, MCRTC_MINUTES); - - /* The following flags have to be released exactly in this order, - * otherwise the DS12887 (popular MC146818A clone with integrated - * battery and quartz) will not reset the oscillator and will not - * update precisely 500 ms later. You won't find this mentioned in - * the Dallas Semiconductor data sheets, but who believes data - * sheets anyway ... -- Markus Kuhn - */ - CMOS_MCRTC_WRITE(save_control, MCRTC_CONTROL); - CMOS_MCRTC_WRITE(save_freq_select, MCRTC_FREQ_SELECT); -} - -/* - * In order to set the CMOS clock precisely, set_rtc_mmss has to be - * called 500 ms after the second nowtime has started, because when - * nowtime is written into the registers of the CMOS clock, it will - * jump to the next second precisely 500 ms later. Check the Motorola - * MC146818A or Dallas DS12887 data sheet for details. - */ -static int set_rtc_mmss(unsigned long nowtime) -{ - int retval = 0; - int real_seconds, real_minutes, cmos_minutes; - unsigned char save_control, save_freq_select; - -#ifdef __powerpc__ -printk("%s: %d - set TOD\n", __FILE__, __LINE__); -return (-1); /* Not implemented */ -#else - -printk("%s: %d - set TOD\n", __FILE__, __LINE__); - save_control = CMOS_MCRTC_READ(MCRTC_CONTROL); /* tell the clock it's being set */ - CMOS_MCRTC_WRITE((save_control|MCRTC_SET), MCRTC_CONTROL); - - save_freq_select = CMOS_MCRTC_READ(MCRTC_FREQ_SELECT); /* stop and reset prescaler */ - CMOS_MCRTC_WRITE((save_freq_select|MCRTC_DIV_RESET2), MCRTC_FREQ_SELECT); - - cmos_minutes = CMOS_MCRTC_READ(MCRTC_MINUTES); - if (!(save_control & MCRTC_DM_BINARY) || MCRTC_ALWAYS_BCD) - BCD_TO_BIN(cmos_minutes); - - /* - * since we're only adjusting minutes and seconds, - * don't interfere with hour overflow. This avoids - * messing with unknown time zones but requires your - * RTC not to be off by more than 15 minutes - */ - real_seconds = nowtime % 60; - real_minutes = nowtime / 60; - if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1) - real_minutes += 30; /* correct for half hour time zone */ - real_minutes %= 60; - - if (abs(real_minutes - cmos_minutes) < 30) { - if (!(save_control & MCRTC_DM_BINARY) || MCRTC_ALWAYS_BCD) { - BIN_TO_BCD(real_seconds); - BIN_TO_BCD(real_minutes); - } - CMOS_MCRTC_WRITE(real_seconds,MCRTC_SECONDS); - CMOS_MCRTC_WRITE(real_minutes,MCRTC_MINUTES); - } else - retval = -1; - - /* The following flags have to be released exactly in this order, - * otherwise the DS12887 (popular MC146818A clone with integrated - * battery and quartz) will not reset the oscillator and will not - * update precisely 500 ms later. You won't find this mentioned in - * the Dallas Semiconductor data sheets, but who believes data - * sheets anyway ... -- Markus Kuhn - */ - CMOS_MCRTC_WRITE(save_control, MCRTC_CONTROL); - CMOS_MCRTC_WRITE(save_freq_select, MCRTC_FREQ_SELECT); - - return retval; -#endif -} - -/* last time the cmos clock got updated */ -static long last_rtc_update = 0; - -/* - * timer_interrupt() needs to keep up the real-time clock, - * as well as call the "do_timer()" routine every clocktick - */ -static inline void timer_interrupt(int irq, void *dev, struct pt_regs * regs) -{ - static int timeints = 0; - - do_timer(regs); - - /* - * If we have an externally synchronized Linux clock, then update - * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be - * called as close as possible to 500 ms before the new second starts. - */ - if (time_state != TIME_BAD && xtime.tv_sec > last_rtc_update + 660 && - xtime.tv_usec > 500000 - (tick >> 1) && - xtime.tv_usec < 500000 + (tick >> 1)) - if (set_rtc_mmss(xtime.tv_sec) == 0) - last_rtc_update = xtime.tv_sec; - else - last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */ - - - /* use hard disk LED as a heartbeat instead -- much more useful - -- Cort */ - switch(timeints) - { - /* act like an actual heart beat -- ie thump-thump-pause... */ - case 0: - case 20: - hard_disk_LED(1); - break; - case 7: - case 27: - hard_disk_LED(0); - break; - case 100: - timeints = -1; - break; - } - timeints++; -} - -/* Converts Gregorian date to seconds since 1970-01-01 00:00:00. - * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 - * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. - * - * [For the Julian calendar (which was used in Russia before 1917, - * Britain & colonies before 1752, anywhere else before 1582, - * and is still in use by some communities) leave out the - * -year/100+year/400 terms, and add 10.] - * - * This algorithm was first published by Gauss (I think). - * - * WARNING: this function will overflow on 2106-02-07 06:28:16 on - * machines were long is 32-bit! (However, as time_t is signed, we - * will already get problems at other places on 2038-01-19 03:14:08) - */ -static inline unsigned long mktime(unsigned int year, unsigned int mon, - unsigned int day, unsigned int hour, - unsigned int min, unsigned int sec) -{ - if (0 >= (int) (mon -= 2)) { /* 1..12 -> 11,12,1..10 */ - mon += 12; /* Puts Feb last since it has leap day */ - year -= 1; - } - return ((( - (unsigned long)(year/4 - year/100 + year/400 + 367*mon/12 + day) + - year*365 - 719499 - )*24 + hour /* now have hours */ - )*60 + min /* now have minutes */ - )*60 + sec; /* finally seconds */ -} - -unsigned long get_cmos_time(void) -{ - unsigned int year, mon, day, hour, min, sec; - int i; - - if (_Processor == _PROC_IBM) - { - do { /* Isn't this overkill ? UIP above should guarantee consistency */ - sec = CMOS_MCRTC_READ(MCRTC_SECONDS); - min = CMOS_MCRTC_READ(MCRTC_MINUTES); - hour = CMOS_MCRTC_READ(MCRTC_HOURS); - day = CMOS_MCRTC_READ(MCRTC_DAY_OF_MONTH); - mon = CMOS_MCRTC_READ(MCRTC_MONTH); - year = CMOS_MCRTC_READ(MCRTC_YEAR); - } while (sec != CMOS_MCRTC_READ(MCRTC_SECONDS)); - BCD_TO_BIN(sec); - BCD_TO_BIN(min); - BCD_TO_BIN(hour); - BCD_TO_BIN(day); - BCD_TO_BIN(mon); - BCD_TO_BIN(year); - } else - if (_Processor == _PROC_Be) - { - do { /* Isn't this overkill ? UIP above should guarantee consistency */ - sec = CMOS_MCRTC_READ(MCRTC_SECONDS); - min = CMOS_MCRTC_READ(MCRTC_MINUTES); - hour = CMOS_MCRTC_READ(MCRTC_HOURS); - day = CMOS_MCRTC_READ(MCRTC_DAY_OF_MONTH); - mon = CMOS_MCRTC_READ(MCRTC_MONTH); - year = CMOS_MCRTC_READ(MCRTC_YEAR); - } while (sec != CMOS_MCRTC_READ(MCRTC_SECONDS)); - } else - { /* Motorola PowerStack etc. */ - do { /* Isn't this overkill ? UIP above should guarantee consistency */ - sec = CMOS_READ(RTC_SECONDS); - min = CMOS_READ(RTC_MINUTES); - hour = CMOS_READ(RTC_HOURS); - day = CMOS_READ(RTC_DAY_OF_MONTH); - mon = CMOS_READ(RTC_MONTH); - year = CMOS_READ(RTC_YEAR); - } while (sec != CMOS_READ(RTC_SECONDS)); - BCD_TO_BIN(sec); - BCD_TO_BIN(min); - BCD_TO_BIN(hour); - BCD_TO_BIN(day); - BCD_TO_BIN(mon); - BCD_TO_BIN(year); - } -#if 0 -printk("CMOS TOD - M/D/Y H:M:S = %d/%d/%d %d:%02d:%02d\n", mon, day, year, hour, min, sec); -#endif - if ((year += 1900) < 1970) - year += 100; - return mktime(year, mon, day, hour, min, sec); -} - -void time_init(void) -{ - void (*irq_handler)(int, struct pt_regs *); - xtime.tv_sec = get_cmos_time(); - xtime.tv_usec = 0; - - /* If we have the CPU hardware time counters, use them */ - irq_handler = timer_interrupt; - if (request_irq(TIMER_IRQ, irq_handler, 0, "timer", NULL) != 0) - panic("Could not allocate timer IRQ!"); -} - |