/* $Id: time.c,v 1.20 1999/03/15 22:13:40 davem Exp $ * time.c: UltraSparc timer and TOD clock support. * * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu) * Copyright (C) 1998 Eddie C. Dost (ecd@skynet.be) * * Based largely on code which is: * * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu) */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include extern rwlock_t xtime_lock; struct mostek48t02 *mstk48t02_regs = 0; static struct mostek48t08 *mstk48t08_regs = 0; static struct mostek48t59 *mstk48t59_regs = 0; static int set_rtc_mmss(unsigned long); /* timer_interrupt() needs to keep up the real-time clock, * as well as call the "do_timer()" routine every clocktick * * NOTE: On SUN5 systems the ticker interrupt comes in using 2 * interrupts, one at level14 and one with softint bit 0. */ unsigned long timer_tick_offset; static unsigned long timer_tick_compare; static unsigned long timer_ticks_per_usec; static __inline__ void timer_check_rtc(void) { /* last time the cmos clock got updated */ static long last_rtc_update=0; /* Determine when to update the Mostek clock. */ if ((time_status & STA_UNSYNC) == 0 && xtime.tv_sec > last_rtc_update + 660 && xtime.tv_usec >= 500000 - ((unsigned) tick) / 2 && xtime.tv_usec <= 500000 + ((unsigned) tick) / 2) { 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 */ } } static void timer_interrupt(int irq, void *dev_id, struct pt_regs * regs) { unsigned long ticks; write_lock(&xtime_lock); do { do_timer(regs); __asm__ __volatile__(" rd %%tick_cmpr, %0 add %0, %2, %0 wr %0, 0, %%tick_cmpr rd %%tick, %1" : "=&r" (timer_tick_compare), "=r" (ticks) : "r" (timer_tick_offset)); } while (ticks >= timer_tick_compare); timer_check_rtc(); write_unlock(&xtime_lock); } #ifdef __SMP__ void timer_tick_interrupt(struct pt_regs *regs) { write_lock(&xtime_lock); do_timer(regs); /* * Only keep timer_tick_offset uptodate, but don't set TICK_CMPR. */ __asm__ __volatile__(" rd %%tick_cmpr, %0 add %0, %1, %0" : "=&r" (timer_tick_compare) : "r" (timer_tick_offset)); timer_check_rtc(); write_unlock(&xtime_lock); } #endif /* 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 */ } /* Kick start a stopped clock (procedure from the Sun NVRAM/hostid FAQ). */ static void __init kick_start_clock(void) { register struct mostek48t02 *regs = mstk48t02_regs; unsigned char sec; int i, count; prom_printf("CLOCK: Clock was stopped. Kick start "); /* Turn on the kick start bit to start the oscillator. */ regs->creg |= MSTK_CREG_WRITE; regs->sec &= ~MSTK_STOP; regs->hour |= MSTK_KICK_START; regs->creg &= ~MSTK_CREG_WRITE; /* Delay to allow the clock oscillator to start. */ sec = MSTK_REG_SEC(regs); for (i = 0; i < 3; i++) { while (sec == MSTK_REG_SEC(regs)) for (count = 0; count < 100000; count++) /* nothing */ ; prom_printf("."); sec = regs->sec; } prom_printf("\n"); /* Turn off kick start and set a "valid" time and date. */ regs->creg |= MSTK_CREG_WRITE; regs->hour &= ~MSTK_KICK_START; MSTK_SET_REG_SEC(regs,0); MSTK_SET_REG_MIN(regs,0); MSTK_SET_REG_HOUR(regs,0); MSTK_SET_REG_DOW(regs,5); MSTK_SET_REG_DOM(regs,1); MSTK_SET_REG_MONTH(regs,8); MSTK_SET_REG_YEAR(regs,1996 - MSTK_YEAR_ZERO); regs->creg &= ~MSTK_CREG_WRITE; /* Ensure the kick start bit is off. If it isn't, turn it off. */ while (regs->hour & MSTK_KICK_START) { prom_printf("CLOCK: Kick start still on!\n"); regs->creg |= MSTK_CREG_WRITE; regs->hour &= ~MSTK_KICK_START; regs->creg &= ~MSTK_CREG_WRITE; } prom_printf("CLOCK: Kick start procedure successful.\n"); } /* Return nonzero if the clock chip battery is low. */ static int __init has_low_battery(void) { register struct mostek48t02 *regs = mstk48t02_regs; unsigned char data1, data2; data1 = regs->eeprom[0]; /* Read some data. */ regs->eeprom[0] = ~data1; /* Write back the complement. */ data2 = regs->eeprom[0]; /* Read back the complement. */ regs->eeprom[0] = data1; /* Restore the original value. */ return (data1 == data2); /* Was the write blocked? */ } /* Probe for the real time clock chip. */ static void __init set_system_time(void) { unsigned int year, mon, day, hour, min, sec; struct mostek48t02 *mregs; do_get_fast_time = do_gettimeofday; mregs = mstk48t02_regs; if(!mregs) { prom_printf("Something wrong, clock regs not mapped yet.\n"); prom_halt(); } mregs->creg |= MSTK_CREG_READ; sec = MSTK_REG_SEC(mregs); min = MSTK_REG_MIN(mregs); hour = MSTK_REG_HOUR(mregs); day = MSTK_REG_DOM(mregs); mon = MSTK_REG_MONTH(mregs); year = MSTK_CVT_YEAR( MSTK_REG_YEAR(mregs) ); xtime.tv_sec = mktime(year, mon, day, hour, min, sec); xtime.tv_usec = 0; mregs->creg &= ~MSTK_CREG_READ; } void __init clock_probe(void) { struct linux_prom_registers clk_reg[2]; char model[128]; int node, busnd = -1, err; unsigned long flags; #ifdef CONFIG_PCI struct linux_ebus *ebus = 0; #endif __save_and_cli(flags); if(central_bus != NULL) { busnd = central_bus->child->prom_node; } #ifdef CONFIG_PCI else if (ebus_chain != NULL) { ebus = ebus_chain; busnd = ebus->prom_node; } #endif else { busnd = SBus_chain->prom_node; } if(busnd == -1) { prom_printf("clock_probe: problem, cannot find bus to search.\n"); prom_halt(); } node = prom_getchild(busnd); while(1) { if (!node) model[0] = 0; else prom_getstring(node, "model", model, sizeof(model)); if(strcmp(model, "mk48t02") && strcmp(model, "mk48t08") && strcmp(model, "mk48t59")) { if (node) node = prom_getsibling(node); #ifdef CONFIG_PCI while ((node == 0) && ebus) { ebus = ebus->next; if (ebus) { busnd = ebus->prom_node; node = prom_getchild(busnd); } } #endif if(node == 0) { prom_printf("clock_probe: Cannot find timer chip\n"); prom_halt(); } continue; } err = prom_getproperty(node, "reg", (char *)clk_reg, sizeof(clk_reg)); if(err == -1) { prom_printf("clock_probe: Cannot get Mostek reg property\n"); prom_halt(); } if(central_bus) { prom_apply_fhc_ranges(central_bus->child, clk_reg, 1); prom_apply_central_ranges(central_bus, clk_reg, 1); } #ifdef CONFIG_PCI else if (ebus_chain) { struct linux_ebus_device *edev; for_each_ebusdev(edev, ebus) if (edev->prom_node == node) break; if (!edev) { prom_printf("%s: Mostek not probed by EBUS\n", __FUNCTION__); prom_halt(); } if (check_region(edev->base_address[0], sizeof(struct mostek48t59))) { prom_printf("%s: Can't get region %lx, %d\n", __FUNCTION__, edev->base_address[0], sizeof(struct mostek48t59)); prom_halt(); } request_region(edev->base_address[0], sizeof(struct mostek48t59), "clock"); mstk48t59_regs = (struct mostek48t59 *) edev->base_address[0]; mstk48t02_regs = &mstk48t59_regs->regs; break; } #endif else { prom_adjust_regs(clk_reg, 1, SBus_chain->sbus_ranges, SBus_chain->num_sbus_ranges); } if(model[5] == '0' && model[6] == '2') { mstk48t02_regs = (struct mostek48t02 *) sparc_alloc_io(clk_reg[0].phys_addr, (void *) 0, sizeof(*mstk48t02_regs), "clock", clk_reg[0].which_io, 0x0); } else if(model[5] == '0' && model[6] == '8') { mstk48t08_regs = (struct mostek48t08 *) sparc_alloc_io(clk_reg[0].phys_addr, (void *) 0, sizeof(*mstk48t08_regs), "clock", clk_reg[0].which_io, 0x0); mstk48t02_regs = &mstk48t08_regs->regs; } else { mstk48t59_regs = (struct mostek48t59 *) sparc_alloc_io(clk_reg[0].phys_addr, (void *) 0, sizeof(*mstk48t59_regs), "clock", clk_reg[0].which_io, 0x0); mstk48t02_regs = &mstk48t59_regs->regs; } break; } /* Report a low battery voltage condition. */ if (has_low_battery()) prom_printf("NVRAM: Low battery voltage!\n"); /* Kick start the clock if it is completely stopped. */ if (mstk48t02_regs->sec & MSTK_STOP) kick_start_clock(); set_system_time(); __restore_flags(flags); } #ifndef BCD_TO_BIN #define BCD_TO_BIN(val) (((val)&15) + ((val)>>4)*10) #endif #ifndef BIN_TO_BCD #define BIN_TO_BCD(val) ((((val)/10)<<4) + (val)%10) #endif extern void init_timers(void (*func)(int, void *, struct pt_regs *), unsigned long *); void __init time_init(void) { /* clock_probe() is now done at end of [se]bus_init on sparc64 * so that sbus, fhc and ebus bus information is probed and * available. */ unsigned long clock; init_timers(timer_interrupt, &clock); timer_tick_offset = clock / HZ; timer_ticks_per_usec = clock / 1000000; } static __inline__ unsigned long do_gettimeoffset(void) { unsigned long ticks; __asm__ __volatile__(" rd %%tick, %%g1 add %1, %%g1, %0 sub %0, %2, %0 " : "=r" (ticks) : "r" (timer_tick_offset), "r" (timer_tick_compare) : "g1", "g2"); return ticks / timer_ticks_per_usec; } /* This need not obtain the xtime_lock as it is coded in * an implicitly SMP safe way already. */ void do_gettimeofday(struct timeval *tv) { /* Load doubles must be used on xtime so that what we get * is guarenteed to be atomic, this is why we can run this * with interrupts on full blast. Don't touch this... -DaveM * * Note with time_t changes to the timeval type, I must now use * nucleus atomic quad 128-bit loads. */ __asm__ __volatile__(" sethi %hi(timer_tick_offset), %g3 sethi %hi(xtime), %g2 sethi %hi(timer_tick_compare), %g1 ldx [%g3 + %lo(timer_tick_offset)], %g3 or %g2, %lo(xtime), %g2 or %g1, %lo(timer_tick_compare), %g1 1: ldda [%g2] 0x24, %o4 membar #LoadLoad | #MemIssue rd %tick, %o1 ldx [%g1], %g7 membar #LoadLoad | #MemIssue ldda [%g2] 0x24, %o2 membar #LoadLoad xor %o4, %o2, %o2 xor %o5, %o3, %o3 orcc %o2, %o3, %g0 bne,pn %xcc, 1b sethi %hi(lost_ticks), %o2 sethi %hi(timer_ticks_per_usec), %o3 ldx [%o2 + %lo(lost_ticks)], %o2 add %g3, %o1, %o1 ldx [%o3 + %lo(timer_ticks_per_usec)], %o3 sub %o1, %g7, %o1 brz,pt %o2, 1f udivx %o1, %o3, %o1 sethi %hi(10000), %g2 or %g2, %lo(10000), %g2 add %o1, %g2, %o1 1: sethi %hi(1000000), %o2 srlx %o5, 32, %o5 or %o2, %lo(1000000), %o2 add %o5, %o1, %o5 cmp %o5, %o2 bl,a,pn %xcc, 1f stx %o4, [%o0 + 0x0] add %o4, 0x1, %o4 sub %o5, %o2, %o5 stx %o4, [%o0 + 0x0] 1: st %o5, [%o0 + 0x8]"); } void do_settimeofday(struct timeval *tv) { write_lock_irq(&xtime_lock); tv->tv_usec -= do_gettimeoffset(); if(tv->tv_usec < 0) { tv->tv_usec += 1000000; tv->tv_sec--; } xtime = *tv; time_adjust = 0; /* stop active adjtime() */ time_status |= STA_UNSYNC; time_maxerror = NTP_PHASE_LIMIT; time_esterror = NTP_PHASE_LIMIT; write_unlock_irq(&xtime_lock); } static int set_rtc_mmss(unsigned long nowtime) { int real_seconds, real_minutes, mostek_minutes; struct mostek48t02 *regs = mstk48t02_regs; /* Not having a register set can lead to trouble. */ if (!regs) return -1; /* Read the current RTC minutes. */ regs->creg |= MSTK_CREG_READ; mostek_minutes = MSTK_REG_MIN(regs); regs->creg &= ~MSTK_CREG_READ; /* * 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 - mostek_minutes) + 15)/30) & 1) real_minutes += 30; /* correct for half hour time zone */ real_minutes %= 60; if (abs(real_minutes - mostek_minutes) < 30) { regs->creg |= MSTK_CREG_WRITE; MSTK_SET_REG_SEC(regs,real_seconds); MSTK_SET_REG_MIN(regs,real_minutes); regs->creg &= ~MSTK_CREG_WRITE; } else return -1; return 0; }