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-rw-r--r--arch/sh/kernel/time_32.c269
1 files changed, 269 insertions, 0 deletions
diff --git a/arch/sh/kernel/time_32.c b/arch/sh/kernel/time_32.c
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+++ b/arch/sh/kernel/time_32.c
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+/*
+ * 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
+}