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Diffstat (limited to 'arch/m32r/kernel/time.c')
| -rw-r--r-- | arch/m32r/kernel/time.c | 318 |
1 files changed, 318 insertions, 0 deletions
diff --git a/arch/m32r/kernel/time.c b/arch/m32r/kernel/time.c new file mode 100644 index 00000000000..3c4707280a5 --- /dev/null +++ b/arch/m32r/kernel/time.c @@ -0,0 +1,318 @@ +/* + * linux/arch/m32r/kernel/time.c + * + * Copyright (c) 2001, 2002 Hiroyuki Kondo, Hirokazu Takata, + * Hitoshi Yamamoto + * Taken from i386 version. + * Copyright (C) 1991, 1992, 1995 Linus Torvalds + * Copyright (C) 1996, 1997, 1998 Ralf Baechle + * + * This file contains the time handling details for PC-style clocks as + * found in some MIPS systems. + * + * Some code taken from sh version. + * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka + * Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org> + */ + +#undef DEBUG_TIMER + +#include <linux/config.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/param.h> +#include <linux/string.h> +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <linux/profile.h> + +#include <asm/io.h> +#include <asm/m32r.h> + +#include <asm/hw_irq.h> + +#ifdef CONFIG_SMP +extern void send_IPI_allbutself(int, int); +extern void smp_local_timer_interrupt(struct pt_regs *); +#endif + +u64 jiffies_64 = INITIAL_JIFFIES; + +EXPORT_SYMBOL(jiffies_64); + +extern unsigned long wall_jiffies; +#define TICK_SIZE (tick_nsec / 1000) + +/* + * Change this if you have some constant time drift + */ + +/* This is for machines which generate the exact clock. */ +#define USECS_PER_JIFFY (1000000/HZ) + +static unsigned long latch; + +static unsigned long do_gettimeoffset(void) +{ + unsigned long elapsed_time = 0; /* [us] */ + +#if defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_XNUX2) \ + || defined(CONFIG_CHIP_VDEC2) || defined(CONFIG_CHIP_M32700) \ + || defined(CONFIG_CHIP_OPSP) +#ifndef CONFIG_SMP + + unsigned long count; + + /* timer count may underflow right here */ + count = inl(M32R_MFT2CUT_PORTL); + + if (inl(M32R_ICU_CR18_PORTL) & 0x00000100) /* underflow check */ + count = 0; + + count = (latch - count) * TICK_SIZE; + elapsed_time = (count + latch / 2) / latch; + /* NOTE: LATCH is equal to the "interval" value (= reload count). */ + +#else /* CONFIG_SMP */ + unsigned long count; + static unsigned long p_jiffies = -1; + static unsigned long p_count = 0; + + /* timer count may underflow right here */ + count = inl(M32R_MFT2CUT_PORTL); + + if (jiffies == p_jiffies && count > p_count) + count = 0; + + p_jiffies = jiffies; + p_count = count; + + count = (latch - count) * TICK_SIZE; + elapsed_time = (count + latch / 2) / latch; + /* NOTE: LATCH is equal to the "interval" value (= reload count). */ +#endif /* CONFIG_SMP */ +#elif defined(CONFIG_CHIP_M32310) +#warning do_gettimeoffse not implemented +#else +#error no chip configuration +#endif + + return elapsed_time; +} + +/* + * This version of gettimeofday has near microsecond resolution. + */ +void do_gettimeofday(struct timeval *tv) +{ + unsigned long seq; + unsigned long usec, sec; + unsigned long max_ntp_tick = tick_usec - tickadj; + + do { + unsigned long lost; + + seq = read_seqbegin(&xtime_lock); + + usec = do_gettimeoffset(); + lost = jiffies - wall_jiffies; + + /* + * 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); + if (lost) + usec += lost * max_ntp_tick; + } else if (unlikely(lost)) + usec += lost * tick_usec; + + 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 -= do_gettimeoffset() * NSEC_PER_USEC; + nsec -= (jiffies - wall_jiffies) * TICK_NSEC; + + 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); + +/* + * 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. + * + * BUG: This routine does not handle hour overflow properly; it just + * sets the minutes. Usually you won't notice until after reboot! + */ +static inline int set_rtc_mmss(unsigned long nowtime) +{ + return 0; +} + +/* 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 +do_timer_interrupt(int irq, void *dev_id, struct pt_regs * regs) +{ +#ifndef CONFIG_SMP + profile_tick(CPU_PROFILING, regs); +#endif + do_timer(regs); + +#ifndef CONFIG_SMP + update_process_times(user_mode(regs)); +#endif + /* + * 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_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 (set_rtc_mmss(xtime.tv_sec) == 0) + last_rtc_update = xtime.tv_sec; + else /* do it again in 60 s */ + last_rtc_update = xtime.tv_sec - 600; + } + /* As we return to user mode fire off the other CPU schedulers.. + this is basically because we don't yet share IRQ's around. + This message is rigged to be safe on the 386 - basically it's + a hack, so don't look closely for now.. */ + +#ifdef CONFIG_SMP + smp_local_timer_interrupt(regs); +#endif +} + +irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) +{ + write_seqlock(&xtime_lock); + do_timer_interrupt(irq, NULL, regs); + write_sequnlock(&xtime_lock); + + return IRQ_HANDLED; +} + +struct irqaction irq0 = { timer_interrupt, SA_INTERRUPT, CPU_MASK_NONE, + "MFT2", NULL, NULL }; + +void __init time_init(void) +{ + unsigned int epoch, year, mon, day, hour, min, sec; + + sec = min = hour = day = mon = year = 0; + epoch = 0; + + year = 23; + mon = 4; + day = 17; + + /* Attempt to guess the epoch. This is the same heuristic as in rtc.c + so no stupid things will happen to timekeeping. Who knows, maybe + Ultrix also uses 1952 as epoch ... */ + if (year > 10 && year < 44) + epoch = 1980; + else if (year < 96) + epoch = 1952; + year += epoch; + + 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); + +#if defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_XNUX2) \ + || defined(CONFIG_CHIP_VDEC2) || defined(CONFIG_CHIP_M32700) \ + || defined(CONFIG_CHIP_OPSP) + + /* M32102 MFT setup */ + setup_irq(M32R_IRQ_MFT2, &irq0); + { + unsigned long bus_clock; + unsigned short divide; + + bus_clock = boot_cpu_data.bus_clock; + divide = boot_cpu_data.timer_divide; + latch = (bus_clock/divide + HZ / 2) / HZ; + + printk("Timer start : latch = %ld\n", latch); + + outl((M32R_MFTMOD_CC_MASK | M32R_MFTMOD_TCCR \ + |M32R_MFTMOD_CSSEL011), M32R_MFT2MOD_PORTL); + outl(latch, M32R_MFT2RLD_PORTL); + outl(latch, M32R_MFT2CUT_PORTL); + outl(0, M32R_MFT2CMPRLD_PORTL); + outl((M32R_MFTCR_MFT2MSK|M32R_MFTCR_MFT2EN), M32R_MFTCR_PORTL); + } + +#elif defined(CONFIG_CHIP_M32310) +#warning time_init not implemented +#else +#error no chip configuration +#endif +} + +/* + * Scheduler clock - returns current time in nanosec units. + */ +unsigned long long sched_clock(void) +{ + return (unsigned long long)jiffies * (1000000000 / HZ); +} |