/* $Id: time.c,v 1.60 2002/01/23 14:33:55 davem Exp $ * linux/arch/sparc/kernel/time.c * * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu) * * Chris Davis (cdavis@cois.on.ca) 03/27/1998 * Added support for the intersil on the sun4/4200 * * Gleb Raiko (rajko@mech.math.msu.su) 08/18/1998 * Support for MicroSPARC-IIep, PCI CPU. * * This file handles the Sparc specific time handling details. * * 1997-09-10 Updated NTP code according to technical memorandum Jan '96 * "A Kernel Model for Precision Timekeeping" by Dave Mills */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include DEFINE_SPINLOCK(rtc_lock); enum sparc_clock_type sp_clock_typ; DEFINE_SPINLOCK(mostek_lock); void __iomem *mstk48t02_regs = NULL; static struct mostek48t08 __iomem *mstk48t08_regs = NULL; static int set_rtc_mmss(unsigned long); static int sbus_do_settimeofday(struct timespec *tv); #ifdef CONFIG_SUN4 struct intersil *intersil_clock; #define intersil_cmd(intersil_reg, intsil_cmd) intersil_reg->int_cmd_reg = \ (intsil_cmd) #define intersil_intr(intersil_reg, intsil_cmd) intersil_reg->int_intr_reg = \ (intsil_cmd) #define intersil_start(intersil_reg) intersil_cmd(intersil_reg, \ ( INTERSIL_START | INTERSIL_32K | INTERSIL_NORMAL | INTERSIL_24H |\ INTERSIL_INTR_ENABLE)) #define intersil_stop(intersil_reg) intersil_cmd(intersil_reg, \ ( INTERSIL_STOP | INTERSIL_32K | INTERSIL_NORMAL | INTERSIL_24H |\ INTERSIL_INTR_ENABLE)) #define intersil_read_intr(intersil_reg, towhere) towhere = \ intersil_reg->int_intr_reg #endif unsigned long profile_pc(struct pt_regs *regs) { extern char __copy_user_begin[], __copy_user_end[]; extern char __atomic_begin[], __atomic_end[]; extern char __bzero_begin[], __bzero_end[]; extern char __bitops_begin[], __bitops_end[]; unsigned long pc = regs->pc; if (in_lock_functions(pc) || (pc >= (unsigned long) __copy_user_begin && pc < (unsigned long) __copy_user_end) || (pc >= (unsigned long) __atomic_begin && pc < (unsigned long) __atomic_end) || (pc >= (unsigned long) __bzero_begin && pc < (unsigned long) __bzero_end) || (pc >= (unsigned long) __bitops_begin && pc < (unsigned long) __bitops_end)) pc = regs->u_regs[UREG_RETPC]; return pc; } __volatile__ unsigned int *master_l10_counter; __volatile__ unsigned int *master_l10_limit; /* * timer_interrupt() needs to keep up the real-time clock, * as well as call the "do_timer()" routine every clocktick */ #define TICK_SIZE (tick_nsec / 1000) irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs * regs) { /* last time the cmos clock got updated */ static long last_rtc_update; #ifndef CONFIG_SMP profile_tick(CPU_PROFILING, regs); #endif /* Protect counter clear so that do_gettimeoffset works */ write_seqlock(&xtime_lock); #ifdef CONFIG_SUN4 if((idprom->id_machtype == (SM_SUN4 | SM_4_260)) || (idprom->id_machtype == (SM_SUN4 | SM_4_110))) { int temp; intersil_read_intr(intersil_clock, temp); /* re-enable the irq */ enable_pil_irq(10); } #endif clear_clock_irq(); do_timer(1); #ifndef CONFIG_SMP update_process_times(user_mode(regs)); #endif /* Determine when to update the Mostek clock. */ if (ntp_synced() && xtime.tv_sec > last_rtc_update + 660 && (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 && (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 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 */ } write_sequnlock(&xtime_lock); return IRQ_HANDLED; } /* Kick start a stopped clock (procedure from the Sun NVRAM/hostid FAQ). */ static void __init kick_start_clock(void) { struct mostek48t02 *regs = (struct mostek48t02 *)mstk48t02_regs; unsigned char sec; int i, count; prom_printf("CLOCK: Clock was stopped. Kick start "); spin_lock_irq(&mostek_lock); /* 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; spin_unlock_irq(&mostek_lock); /* 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"); spin_lock_irq(&mostek_lock); /* 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; spin_unlock_irq(&mostek_lock); /* 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"); spin_lock_irq(&mostek_lock); regs->creg |= MSTK_CREG_WRITE; regs->hour &= ~MSTK_KICK_START; regs->creg &= ~MSTK_CREG_WRITE; spin_unlock_irq(&mostek_lock); } prom_printf("CLOCK: Kick start procedure successful.\n"); } /* Return nonzero if the clock chip battery is low. */ static __inline__ int has_low_battery(void) { struct mostek48t02 *regs = (struct mostek48t02 *)mstk48t02_regs; unsigned char data1, data2; spin_lock_irq(&mostek_lock); 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. */ spin_unlock_irq(&mostek_lock); return (data1 == data2); /* Was the write blocked? */ } static void __init mostek_set_system_time(void) { unsigned int year, mon, day, hour, min, sec; struct mostek48t02 *mregs; mregs = (struct mostek48t02 *)mstk48t02_regs; if(!mregs) { prom_printf("Something wrong, clock regs not mapped yet.\n"); prom_halt(); } spin_lock_irq(&mostek_lock); 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_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ); set_normalized_timespec(&wall_to_monotonic, -xtime.tv_sec, -xtime.tv_nsec); mregs->creg &= ~MSTK_CREG_READ; spin_unlock_irq(&mostek_lock); } /* Probe for the real time clock chip on Sun4 */ static __inline__ void sun4_clock_probe(void) { #ifdef CONFIG_SUN4 int temp; struct resource r; memset(&r, 0, sizeof(r)); if( idprom->id_machtype == (SM_SUN4 | SM_4_330) ) { sp_clock_typ = MSTK48T02; r.start = sun4_clock_physaddr; mstk48t02_regs = sbus_ioremap(&r, 0, sizeof(struct mostek48t02), NULL); mstk48t08_regs = NULL; /* To catch weirdness */ intersil_clock = NULL; /* just in case */ /* Kick start the clock if it is completely stopped. */ if (mostek_read(mstk48t02_regs + MOSTEK_SEC) & MSTK_STOP) kick_start_clock(); } else if( idprom->id_machtype == (SM_SUN4 | SM_4_260)) { /* intersil setup code */ printk("Clock: INTERSIL at %8x ",sun4_clock_physaddr); sp_clock_typ = INTERSIL; r.start = sun4_clock_physaddr; intersil_clock = (struct intersil *) sbus_ioremap(&r, 0, sizeof(*intersil_clock), "intersil"); mstk48t02_regs = 0; /* just be sure */ mstk48t08_regs = NULL; /* ditto */ /* initialise the clock */ intersil_intr(intersil_clock,INTERSIL_INT_100HZ); intersil_start(intersil_clock); intersil_read_intr(intersil_clock, temp); while (!(temp & 0x80)) intersil_read_intr(intersil_clock, temp); intersil_read_intr(intersil_clock, temp); while (!(temp & 0x80)) intersil_read_intr(intersil_clock, temp); intersil_stop(intersil_clock); } #endif } #ifndef CONFIG_SUN4 static int __devinit clock_probe(struct of_device *op, const struct of_device_id *match) { struct device_node *dp = op->node; char *model = of_get_property(dp, "model", NULL); if (!model) return -ENODEV; if (!strcmp(model, "mk48t02")) { sp_clock_typ = MSTK48T02; /* Map the clock register io area read-only */ mstk48t02_regs = of_ioremap(&op->resource[0], 0, sizeof(struct mostek48t02), "mk48t02"); mstk48t08_regs = NULL; /* To catch weirdness */ } else if (!strcmp(model, "mk48t08")) { sp_clock_typ = MSTK48T08; mstk48t08_regs = of_ioremap(&op->resource[0], 0, sizeof(struct mostek48t08), "mk48t08"); mstk48t02_regs = &mstk48t08_regs->regs; } else return -ENODEV; /* Report a low battery voltage condition. */ if (has_low_battery()) printk(KERN_CRIT "NVRAM: Low battery voltage!\n"); /* Kick start the clock if it is completely stopped. */ if (mostek_read(mstk48t02_regs + MOSTEK_SEC) & MSTK_STOP) kick_start_clock(); mostek_set_system_time(); return 0; } static struct of_device_id clock_match[] = { { .name = "eeprom", }, {}, }; static struct of_platform_driver clock_driver = { .name = "clock", .match_table = clock_match, .probe = clock_probe, }; /* Probe for the mostek real time clock chip. */ static int __init clock_init(void) { return of_register_driver(&clock_driver, &of_bus_type); } /* Must be after subsys_initcall() so that busses are probed. Must * be before device_initcall() because things like the RTC driver * need to see the clock registers. */ fs_initcall(clock_init); #endif /* !CONFIG_SUN4 */ void __init sbus_time_init(void) { BTFIXUPSET_CALL(bus_do_settimeofday, sbus_do_settimeofday, BTFIXUPCALL_NORM); btfixup(); if (ARCH_SUN4) sun4_clock_probe(); sparc_init_timers(timer_interrupt); #ifdef CONFIG_SUN4 if(idprom->id_machtype == (SM_SUN4 | SM_4_330)) { mostek_set_system_time(); } else if(idprom->id_machtype == (SM_SUN4 | SM_4_260) ) { /* initialise the intersil on sun4 */ unsigned int year, mon, day, hour, min, sec; int temp; struct intersil *iregs; iregs=intersil_clock; if(!iregs) { prom_printf("Something wrong, clock regs not mapped yet.\n"); prom_halt(); } intersil_intr(intersil_clock,INTERSIL_INT_100HZ); disable_pil_irq(10); intersil_stop(iregs); intersil_read_intr(intersil_clock, temp); temp = iregs->clk.int_csec; sec = iregs->clk.int_sec; min = iregs->clk.int_min; hour = iregs->clk.int_hour; day = iregs->clk.int_day; mon = iregs->clk.int_month; year = MSTK_CVT_YEAR(iregs->clk.int_year); enable_pil_irq(10); intersil_start(iregs); xtime.tv_sec = mktime(year, mon, day, hour, min, sec); xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ); set_normalized_timespec(&wall_to_monotonic, -xtime.tv_sec, -xtime.tv_nsec); printk("%u/%u/%u %u:%u:%u\n",day,mon,year,hour,min,sec); } #endif /* Now that OBP ticker has been silenced, it is safe to enable IRQ. */ local_irq_enable(); } void __init time_init(void) { #ifdef CONFIG_PCI extern void pci_time_init(void); if (pcic_present()) { pci_time_init(); return; } #endif sbus_time_init(); } static inline unsigned long do_gettimeoffset(void) { return (*master_l10_counter >> 10) & 0x1fffff; } /* * Returns nanoseconds * XXX This is a suboptimal implementation. */ unsigned long long sched_clock(void) { return (unsigned long long)jiffies * (1000000000 / HZ); } /* Ok, my cute asm atomicity trick doesn't work anymore. * There are just too many variables that need to be protected * now (both members of xtime, et al.) */ void do_gettimeofday(struct timeval *tv) { unsigned long flags; unsigned long seq; unsigned long usec, sec; unsigned long max_ntp_tick = tick_usec - tickadj; do { seq = read_seqbegin_irqsave(&xtime_lock, flags); usec = do_gettimeoffset(); /* * If time_adjust is negative then NTP is slowing the clock * so make sure not to go into next possible interval. * Better to lose some accuracy than have time go backwards.. */ if (unlikely(time_adjust < 0)) usec = min(usec, max_ntp_tick); sec = xtime.tv_sec; usec += (xtime.tv_nsec / 1000); } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); while (usec >= 1000000) { usec -= 1000000; sec++; } tv->tv_sec = sec; tv->tv_usec = usec; } EXPORT_SYMBOL(do_gettimeofday); int do_settimeofday(struct timespec *tv) { int ret; write_seqlock_irq(&xtime_lock); ret = bus_do_settimeofday(tv); write_sequnlock_irq(&xtime_lock); clock_was_set(); return ret; } EXPORT_SYMBOL(do_settimeofday); static int sbus_do_settimeofday(struct timespec *tv) { time_t wtm_sec, sec = tv->tv_sec; long wtm_nsec, nsec = tv->tv_nsec; if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) return -EINVAL; /* * This is revolting. We need to set "xtime" correctly. However, the * value in this location is the value at the most recent update of * wall time. Discover what correction gettimeofday() would have * made, and then undo it! */ nsec -= 1000 * do_gettimeoffset(); wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); set_normalized_timespec(&xtime, sec, nsec); set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); ntp_clear(); return 0; } /* * BUG: This routine does not handle hour overflow properly; it just * sets the minutes. Usually you won't notice until after reboot! */ static int set_rtc_mmss(unsigned long nowtime) { int real_seconds, real_minutes, mostek_minutes; struct mostek48t02 *regs = (struct mostek48t02 *)mstk48t02_regs; unsigned long flags; #ifdef CONFIG_SUN4 struct intersil *iregs = intersil_clock; int temp; #endif /* Not having a register set can lead to trouble. */ if (!regs) { #ifdef CONFIG_SUN4 if(!iregs) return -1; else { temp = iregs->clk.int_csec; mostek_minutes = iregs->clk.int_min; 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) { intersil_stop(iregs); iregs->clk.int_sec=real_seconds; iregs->clk.int_min=real_minutes; intersil_start(iregs); } else { printk(KERN_WARNING "set_rtc_mmss: can't update from %d to %d\n", mostek_minutes, real_minutes); return -1; } return 0; } #endif } spin_lock_irqsave(&mostek_lock, flags); /* 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; spin_unlock_irqrestore(&mostek_lock, flags); return 0; } else { spin_unlock_irqrestore(&mostek_lock, flags); return -1; } }