diff options
Diffstat (limited to 'arch/sh/kernel/time_32.c')
| -rw-r--r-- | arch/sh/kernel/time_32.c | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/arch/sh/kernel/time_32.c b/arch/sh/kernel/time_32.c new file mode 100644 index 00000000000..2bc04bfee73 --- /dev/null +++ b/arch/sh/kernel/time_32.c @@ -0,0 +1,269 @@ +/* + * 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) +{ + do_timer(1); +#ifndef CONFIG_SMP + update_process_times(user_mode(get_irq_regs())); +#endif + if (current->pid) + profile_tick(CPU_PROFILING); + +#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 (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; + } +} +#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 +} |