/* $Id: time.c,v 1.19 2004/02/27 00:40:48 lethal Exp $ * * linux/arch/sh/kernel/time.c * * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka * Copyright (C) 2000 Philipp Rumpf * Copyright (C) 2002, 2003 Paul Mundt * Copyright (C) 2002 M. R. Brown * * Some code taken from i386 version. * Copyright (C) 1991, 1992, 1995 Linus Torvalds */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_SH_KGDB #include #endif #include #include #define TMU_TOCR_INIT 0x00 #define TMU0_TCR_INIT 0x0020 #define TMU_TSTR_INIT 1 #define TMU0_TCR_CALIB 0x0000 #if defined(CONFIG_CPU_SH3) #define TMU_TOCR 0xfffffe90 /* Byte access */ #define TMU_TSTR 0xfffffe92 /* Byte access */ #define TMU0_TCOR 0xfffffe94 /* Long access */ #define TMU0_TCNT 0xfffffe98 /* Long access */ #define TMU0_TCR 0xfffffe9c /* Word access */ #elif defined(CONFIG_CPU_SH4) #define TMU_TOCR 0xffd80000 /* Byte access */ #define TMU_TSTR 0xffd80004 /* Byte access */ #define TMU0_TCOR 0xffd80008 /* Long access */ #define TMU0_TCNT 0xffd8000c /* Long access */ #define TMU0_TCR 0xffd80010 /* Word access */ #ifdef CONFIG_CPU_SUBTYPE_ST40STB1 #define CLOCKGEN_MEMCLKCR 0xbb040038 #define MEMCLKCR_RATIO_MASK 0x7 #endif /* CONFIG_CPU_SUBTYPE_ST40STB1 */ #endif /* CONFIG_CPU_SH3 or CONFIG_CPU_SH4 */ extern unsigned long wall_jiffies; #define TICK_SIZE (tick_nsec / 1000) spinlock_t tmu0_lock = SPIN_LOCK_UNLOCKED; u64 jiffies_64 = INITIAL_JIFFIES; EXPORT_SYMBOL(jiffies_64); /* XXX: Can we initialize this in a routine somewhere? Dreamcast doesn't want * these routines anywhere... */ #ifdef CONFIG_SH_RTC void (*rtc_get_time)(struct timespec *) = sh_rtc_gettimeofday; int (*rtc_set_time)(const time_t) = sh_rtc_settimeofday; #else void (*rtc_get_time)(struct timespec *) = 0; int (*rtc_set_time)(const time_t) = 0; #endif #if defined(CONFIG_CPU_SH3) static int stc_multipliers[] = { 1, 2, 3, 4, 6, 1, 1, 1 }; static int stc_values[] = { 0, 1, 4, 2, 5, 0, 0, 0 }; #define bfc_divisors stc_multipliers #define bfc_values stc_values static int ifc_divisors[] = { 1, 2, 3, 4, 1, 1, 1, 1 }; static int ifc_values[] = { 0, 1, 4, 2, 0, 0, 0, 0 }; static int pfc_divisors[] = { 1, 2, 3, 4, 6, 1, 1, 1 }; static int pfc_values[] = { 0, 1, 4, 2, 5, 0, 0, 0 }; #elif defined(CONFIG_CPU_SH4) static int ifc_divisors[] = { 1, 2, 3, 4, 6, 8, 1, 1 }; static int ifc_values[] = { 0, 1, 2, 3, 0, 4, 0, 5 }; #define bfc_divisors ifc_divisors /* Same */ #define bfc_values ifc_values static int pfc_divisors[] = { 2, 3, 4, 6, 8, 2, 2, 2 }; static int pfc_values[] = { 0, 0, 1, 2, 0, 3, 0, 4 }; #else #error "Unknown ifc/bfc/pfc/stc values for this processor" #endif /* * Scheduler clock - returns current time in nanosec units. */ unsigned long long sched_clock(void) { return (unsigned long long)jiffies * (1000000000 / HZ); } static unsigned long do_gettimeoffset(void) { int count; unsigned long flags; static int count_p = 0x7fffffff; /* for the first call after boot */ static unsigned long jiffies_p = 0; /* * cache volatile jiffies temporarily; we have IRQs turned off. */ unsigned long jiffies_t; spin_lock_irqsave(&tmu0_lock, flags); /* timer count may underflow right here */ count = ctrl_inl(TMU0_TCNT); /* read the latched count */ jiffies_t = jiffies; /* * avoiding timer inconsistencies (they are rare, but they happen)... * there is one kind of problem that must be avoided here: * 1. the timer counter underflows */ if( jiffies_t == jiffies_p ) { if( count > count_p ) { /* the nutcase */ if(ctrl_inw(TMU0_TCR) & 0x100) { /* Check UNF bit */ /* * We cannot detect lost timer interrupts ... * well, that's why we call them lost, don't we? :) * [hmm, on the Pentium and Alpha we can ... sort of] */ count -= LATCH; } else { printk("do_slow_gettimeoffset(): hardware timer problem?\n"); } } } else jiffies_p = jiffies_t; count_p = count; spin_unlock_irqrestore(&tmu0_lock, flags); count = ((LATCH-1) - count) * TICK_SIZE; count = (count + LATCH/2) / LATCH; return count; } void do_gettimeofday(struct timeval *tv) { unsigned long seq; unsigned long usec, sec; unsigned long lost; do { seq = read_seqbegin(&xtime_lock); usec = do_gettimeoffset(); lost = jiffies - wall_jiffies; if (lost) usec += lost * (1000000 / HZ); sec = xtime.tv_sec; usec += xtime.tv_nsec / 1000; } while (read_seqretry(&xtime_lock, seq)); while (usec >= 1000000) { usec -= 1000000; sec++; } tv->tv_sec = sec; tv->tv_usec = usec; } EXPORT_SYMBOL(do_gettimeofday); int 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; write_seqlock_irq(&xtime_lock); /* * 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() + (jiffies - wall_jiffies) * (1000000 / HZ)); 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); time_adjust = 0; /* stop active adjtime() */ time_status |= STA_UNSYNC; time_maxerror = NTP_PHASE_LIMIT; time_esterror = NTP_PHASE_LIMIT; write_sequnlock_irq(&xtime_lock); clock_was_set(); return 0; } EXPORT_SYMBOL(do_settimeofday); /* last time the RTC clock got updated */ static long last_rtc_update; /* Profiling definitions */ extern unsigned long prof_cpu_mask; extern unsigned int * prof_buffer; extern unsigned long prof_len; extern unsigned long prof_shift; extern char _stext; static inline void sh_do_profile(unsigned long pc) { /* Don't profile cpu_idle.. */ if (!prof_buffer || !current->pid) return; if (pc >= 0xa0000000UL && pc < 0xc0000000UL) pc -= 0x20000000; pc -= (unsigned long)&_stext; pc >>= prof_shift; /* * Don't ignore out-of-bounds PC values silently, * put them into the last histogram slot, so if * present, they will show up as a sharp peak. */ if (pc > prof_len - 1) pc = prof_len - 1; atomic_inc((atomic_t *)&prof_buffer[pc]); } /* * timer_interrupt() needs to keep up the real-time clock, * as well as call the "do_timer()" routine every clocktick */ static inline void do_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) { do_timer(regs); if (!user_mode(regs)) sh_do_profile(regs->pc); #ifdef CONFIG_HEARTBEAT if (sh_mv.mv_heartbeat != NULL) sh_mv.mv_heartbeat(); #endif /* * If we have an externally synchronized Linux clock, then update * RTC 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_status & STA_UNSYNC) == 0 && 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 (rtc_set_time(xtime.tv_sec) == 0) last_rtc_update = xtime.tv_sec; else last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */ } } /* * This is the same as the above, except we _also_ save the current * Time Stamp Counter value at the time of the timer interrupt, so that * we later on can estimate the time of day more exactly. */ static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) { unsigned long timer_status; /* Clear UNF bit */ timer_status = ctrl_inw(TMU0_TCR); timer_status &= ~0x100; ctrl_outw(timer_status, TMU0_TCR); /* * Here we are in the timer irq handler. We just have irqs locally * disabled but we don't know if the timer_bh is running on the other * CPU. We need to avoid to SMP race with it. NOTE: we don' t need * the irq version of write_lock because as just said we have irq * locally disabled. -arca */ write_seqlock(&xtime_lock); do_timer_interrupt(irq, NULL, regs); write_sequnlock(&xtime_lock); return IRQ_HANDLED; } /* * Hah! We'll see if this works (switching from usecs to nsecs). */ static unsigned int __init get_timer_frequency(void) { u32 freq; struct timespec ts1, ts2; unsigned long diff_nsec; unsigned long factor; /* Setup the timer: We don't want to generate interrupts, just * have it count down at its natural rate. */ ctrl_outb(0, TMU_TSTR); ctrl_outb(TMU_TOCR_INIT, TMU_TOCR); ctrl_outw(TMU0_TCR_CALIB, TMU0_TCR); ctrl_outl(0xffffffff, TMU0_TCOR); ctrl_outl(0xffffffff, TMU0_TCNT); rtc_get_time(&ts2); do { rtc_get_time(&ts1); } while (ts1.tv_nsec == ts2.tv_nsec && ts1.tv_sec == ts2.tv_sec); /* actually start the timer */ ctrl_outb(TMU_TSTR_INIT, TMU_TSTR); do { rtc_get_time(&ts2); } while (ts1.tv_nsec == ts2.tv_nsec && ts1.tv_sec == ts2.tv_sec); freq = 0xffffffff - ctrl_inl(TMU0_TCNT); if (ts2.tv_nsec < ts1.tv_nsec) { ts2.tv_nsec += 1000000000; ts2.tv_sec--; } diff_nsec = (ts2.tv_sec - ts1.tv_sec) * 1000000000 + (ts2.tv_nsec - ts1.tv_nsec); /* this should work well if the RTC has a precision of n Hz, where * n is an integer. I don't think we have to worry about the other * cases. */ factor = (1000000000 + diff_nsec/2) / diff_nsec; if (factor * diff_nsec > 1100000000 || factor * diff_nsec < 900000000) panic("weird RTC (diff_nsec %ld)", diff_nsec); return freq * factor; } void (*board_time_init)(void) = 0; void (*board_timer_setup)(struct irqaction *irq) = 0; static unsigned int sh_pclk_freq __initdata = CONFIG_SH_PCLK_FREQ; static int __init sh_pclk_setup(char *str) { unsigned int freq; if (get_option(&str, &freq)) sh_pclk_freq = freq; return 1; } __setup("sh_pclk=", sh_pclk_setup); static struct irqaction irq0 = { timer_interrupt, SA_INTERRUPT, 0, "timer", NULL, NULL}; void get_current_frequency_divisors(unsigned int *ifc, unsigned int *bfc, unsigned int *pfc) { unsigned int frqcr = ctrl_inw(FRQCR); #if defined(CONFIG_CPU_SH3) unsigned int tmp; tmp = (frqcr & 0x8000) >> 13; tmp |= (frqcr & 0x0030) >> 4; *bfc = stc_multipliers[tmp]; tmp = (frqcr & 0x4000) >> 12; tmp |= (frqcr & 0x000c) >> 2; *ifc = ifc_divisors[tmp]; tmp = (frqcr & 0x2000) >> 11; tmp |= frqcr & 0x0003; *pfc = pfc_divisors[tmp]; #elif defined(CONFIG_CPU_SH4) *ifc = ifc_divisors[(frqcr >> 6) & 0x0007]; *bfc = bfc_divisors[(frqcr >> 3) & 0x0007]; *pfc = pfc_divisors[frqcr & 0x0007]; #endif } /* * This bit of ugliness builds up accessor routines to get at both * the divisors and the physical values. */ #define _FREQ_TABLE(x) \ unsigned int get_##x##_divisor(unsigned int value) \ { return x##_divisors[value]; } \ \ unsigned int get_##x##_value(unsigned int divisor) \ { return x##_values[(divisor - 1)]; } _FREQ_TABLE(ifc); _FREQ_TABLE(bfc); _FREQ_TABLE(pfc); void __init time_init(void) { unsigned int timer_freq = 0; unsigned int ifc, pfc, bfc; unsigned long interval; if (board_time_init) board_time_init(); get_current_frequency_divisors(&ifc, &bfc, &pfc); /* * If we don't have an RTC (such as with the SH7300), don't attempt to * probe the timer frequency. Rely on an either hardcoded peripheral * clock value, or on the sh_pclk command line option. */ current_cpu_data.module_clock = sh_pclk_freq; /* XXX: Switch this over to a more generic test. */ if (current_cpu_data.type != CPU_SH7300) { unsigned int freq; /* * If we've specified a peripheral clock frequency, and we have * an RTC, compare it against the autodetected value. Complain * if there's a mismatch. * * Note: We should allow for some high and low watermarks for * the frequency here (compensating for potential drift), as * otherwise we'll likely end up triggering this essentially * on every boot. */ timer_freq = get_timer_frequency(); freq = timer_freq * 4; if (sh_pclk_freq && sh_pclk_freq != freq) { printk(KERN_NOTICE "Calculated peripheral clock value " "%d differs from sh_pclk value %d, fixing..\n", freq, sh_pclk_freq); current_cpu_data.module_clock = freq; } } rtc_get_time(&xtime); set_normalized_timespec(&wall_to_monotonic, -xtime.tv_sec, -xtime.tv_nsec); if (board_timer_setup) { board_timer_setup(&irq0); } else { setup_irq(TIMER_IRQ, &irq0); } if (!current_cpu_data.master_clock) current_cpu_data.master_clock = current_cpu_data.module_clock * pfc; if (!current_cpu_data.bus_clock) current_cpu_data.bus_clock = current_cpu_data.master_clock / bfc; if (!current_cpu_data.cpu_clock) current_cpu_data.cpu_clock = current_cpu_data.master_clock / ifc; printk("CPU clock: %d.%02dMHz\n", (current_cpu_data.cpu_clock / 1000000), (current_cpu_data.cpu_clock % 1000000)/10000); printk("Bus clock: %d.%02dMHz\n", (current_cpu_data.bus_clock / 1000000), (current_cpu_data.bus_clock % 1000000)/10000); #ifdef CONFIG_CPU_SUBTYPE_ST40STB1 printk("Memory clock: %d.%02dMHz\n", (current_cpu_data.memory_clock / 1000000), (current_cpu_data.memory_clock % 1000000)/10000); #endif printk("Module clock: %d.%02dMHz\n", (current_cpu_data.module_clock / 1000000), (current_cpu_data.module_clock % 1000000)/10000); interval = (current_cpu_data.module_clock/4 + HZ/2) / HZ; printk("Interval = %ld\n", interval); /* Start TMU0 */ ctrl_outb(0, TMU_TSTR); ctrl_outb(TMU_TOCR_INIT, TMU_TOCR); ctrl_outw(TMU0_TCR_INIT, TMU0_TCR); ctrl_outl(interval, TMU0_TCOR); ctrl_outl(interval, TMU0_TCNT); ctrl_outb(TMU_TSTR_INIT, TMU_TSTR); #if defined(CONFIG_SH_KGDB) /* * Set up kgdb as requested. We do it here because the serial * init uses the timer vars we just set up for figuring baud. */ kgdb_init(); #endif }