/* * arch/sh/kernel/time.c * * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka * Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org> * Copyright (C) 2002 - 2007 Paul Mundt * Copyright (C) 2002 M. R. Brown <mrbrown@linux-sh.org> * * Some code taken from i386 version. * Copyright (C) 1991, 1992, 1995 Linus Torvalds */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/profile.h> #include <linux/timex.h> #include <linux/sched.h> #include <linux/clockchips.h> #include <asm/clock.h> #include <asm/rtc.h> #include <asm/timer.h> #include <asm/kgdb.h> struct sys_timer *sys_timer; /* Move this somewhere more sensible.. */ DEFINE_SPINLOCK(rtc_lock); EXPORT_SYMBOL(rtc_lock); /* Dummy RTC ops */ static void null_rtc_get_time(struct timespec *tv) { tv->tv_sec = mktime(2000, 1, 1, 0, 0, 0); tv->tv_nsec = 0; } static int null_rtc_set_time(const time_t secs) { return 0; } /* * Null high precision timer functions for systems lacking one. */ static cycle_t null_hpt_read(void) { return 0; } void (*rtc_sh_get_time)(struct timespec *) = null_rtc_get_time; int (*rtc_sh_set_time)(const time_t) = null_rtc_set_time; #ifndef CONFIG_GENERIC_TIME void do_gettimeofday(struct timeval *tv) { unsigned long flags; unsigned long seq; unsigned long usec, sec; do { /* * Turn off IRQs when grabbing xtime_lock, so that * the sys_timer get_offset code doesn't have to handle it. */ seq = read_seqbegin_irqsave(&xtime_lock, flags); usec = get_timer_offset(); sec = xtime.tv_sec; usec += xtime.tv_nsec / NSEC_PER_USEC; } 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) { 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 -= get_timer_offset() * NSEC_PER_USEC; 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(); write_sequnlock_irq(&xtime_lock); clock_was_set(); return 0; } EXPORT_SYMBOL(do_settimeofday); #endif /* !CONFIG_GENERIC_TIME */ #ifndef CONFIG_GENERIC_CLOCKEVENTS /* last time the RTC clock got updated */ static long last_rtc_update; /* * handle_timer_tick() needs to keep up the real-time clock, * as well as call the "do_timer()" routine every clocktick */ void handle_timer_tick(void) { if (current->pid) profile_tick(CPU_PROFILING); #ifdef CONFIG_HEARTBEAT if (sh_mv.mv_heartbeat != NULL) sh_mv.mv_heartbeat(); #endif /* * 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(1); /* * 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 (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 (rtc_sh_set_time(xtime.tv_sec) == 0) last_rtc_update = xtime.tv_sec; else /* do it again in 60s */ last_rtc_update = xtime.tv_sec - 600; } write_sequnlock(&xtime_lock); #ifndef CONFIG_SMP update_process_times(user_mode(get_irq_regs())); #endif } #endif /* !CONFIG_GENERIC_CLOCKEVENTS */ #ifdef CONFIG_PM int timer_suspend(struct sys_device *dev, pm_message_t state) { struct sys_timer *sys_timer = container_of(dev, struct sys_timer, dev); sys_timer->ops->stop(); return 0; } int timer_resume(struct sys_device *dev) { struct sys_timer *sys_timer = container_of(dev, struct sys_timer, dev); sys_timer->ops->start(); return 0; } #else #define timer_suspend NULL #define timer_resume NULL #endif static struct sysdev_class timer_sysclass = { .name = "timer", .suspend = timer_suspend, .resume = timer_resume, }; static int __init timer_init_sysfs(void) { int ret = sysdev_class_register(&timer_sysclass); if (ret != 0) return ret; sys_timer->dev.cls = &timer_sysclass; return sysdev_register(&sys_timer->dev); } device_initcall(timer_init_sysfs); void (*board_time_init)(void); /* * Shamelessly based on the MIPS and Sparc64 work. */ static unsigned long timer_ticks_per_nsec_quotient __read_mostly; unsigned long sh_hpt_frequency = 0; #define NSEC_PER_CYC_SHIFT 10 struct clocksource clocksource_sh = { .name = "SuperH", .rating = 200, .mask = CLOCKSOURCE_MASK(32), .read = null_hpt_read, .shift = 16, .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; static void __init init_sh_clocksource(void) { if (!sh_hpt_frequency || clocksource_sh.read == null_hpt_read) return; clocksource_sh.mult = clocksource_hz2mult(sh_hpt_frequency, clocksource_sh.shift); timer_ticks_per_nsec_quotient = clocksource_hz2mult(sh_hpt_frequency, NSEC_PER_CYC_SHIFT); clocksource_register(&clocksource_sh); } #ifdef CONFIG_GENERIC_TIME unsigned long long sched_clock(void) { unsigned long long ticks = clocksource_sh.read(); return (ticks * timer_ticks_per_nsec_quotient) >> NSEC_PER_CYC_SHIFT; } #endif void __init time_init(void) { if (board_time_init) board_time_init(); clk_init(); rtc_sh_get_time(&xtime); set_normalized_timespec(&wall_to_monotonic, -xtime.tv_sec, -xtime.tv_nsec); /* * Find the timer to use as the system timer, it will be * initialized for us. */ sys_timer = get_sys_timer(); printk(KERN_INFO "Using %s for system timer\n", sys_timer->name); if (sys_timer->ops->read) clocksource_sh.read = sys_timer->ops->read; init_sh_clocksource(); if (sh_hpt_frequency) printk("Using %lu.%03lu MHz high precision timer.\n", ((sh_hpt_frequency + 500) / 1000) / 1000, ((sh_hpt_frequency + 500) / 1000) % 1000); #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 }