1 files changed, 234 insertions, 0 deletions

diff --git a/arch/arm26/kernel/time.c b/arch/arm26/kernel/time.c
new file mode 100644
index 000000000000..549a6b2e177e
--- /dev/null
+++ b/arch/arm26/kernel/time.c
@@ -0,0 +1,234 @@
+/*
+ *  linux/arch/arm26/kernel/time.c
+ *
+ *  Copyright (C) 1991, 1992, 1995  Linus Torvalds
+ *  Modifications for ARM (C) 1994-2001 Russell King
+ *  Mods for ARM26 (C) 2003 Ian Molton
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ *  This file contains the ARM-specific time handling details:
+ *  reading the RTC at bootup, etc...
+ *
+ *  1994-07-02  Alan Modra
+ *              fixed set_rtc_mmss, fixed time.year for >= 2000, new mktime
+ *  1998-12-20  Updated NTP code according to technical memorandum Jan '96
+ *              "A Kernel Model for Precision Timekeeping" by Dave Mills
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/timex.h>
+#include <linux/errno.h>
+#include <linux/profile.h>
+
+#include <asm/hardware.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/ioc.h>
+
+u64 jiffies_64 = INITIAL_JIFFIES;
+
+EXPORT_SYMBOL(jiffies_64);
+
+extern unsigned long wall_jiffies;
+
+/* this needs a better home */
+DEFINE_SPINLOCK(rtc_lock);
+
+/* change this if you have some constant time drift */
+#define USECS_PER_JIFFY (1000000/HZ)
+
+static int dummy_set_rtc(void)
+{
+        return 0;
+}
+
+/*
+ * hook for setting the RTC's idea of the current time.
+ */
+int (*set_rtc)(void) = dummy_set_rtc;
+
+/*
+ * Get time offset based on IOCs timer.
+ * FIXME - if this is called with interrutps off, why the shennanigans
+ * below ?
+ */
+static unsigned long gettimeoffset(void)
+{
+        unsigned int count1, count2, status;
+        long offset;
+
+        ioc_writeb (0, IOC_T0LATCH);
+        barrier ();
+        count1 = ioc_readb(IOC_T0CNTL) | (ioc_readb(IOC_T0CNTH) << 8);
+        barrier ();
+        status = ioc_readb(IOC_IRQREQA);
+        barrier ();
+        ioc_writeb (0, IOC_T0LATCH);
+        barrier ();
+        count2 = ioc_readb(IOC_T0CNTL) | (ioc_readb(IOC_T0CNTH) << 8);
+
+        offset = count2;
+        if (count2 < count1) {
+                /*
+                 * We have not had an interrupt between reading count1
+                 * and count2.
+                 */
+                if (status & (1 << 5))
+                        offset -= LATCH;
+        } else if (count2 > count1) {
+                /*
+                 * We have just had another interrupt between reading
+                 * count1 and count2.
+                 */
+                offset -= LATCH;
+        }
+
+        offset = (LATCH - offset) * (tick_nsec / 1000);
+        return (offset + LATCH/2) / LATCH;
+}
+
+/*
+ * Scheduler clock - returns current time in nanosec units.
+ */
+unsigned long long sched_clock(void)
+{
+        return (unsigned long long)jiffies * (1000000000 / HZ);
+}
+
+static unsigned long next_rtc_update;
+
+/*
+ * If we have an externally synchronized linux clock, then update
+ * CMOS clock accordingly every ~11 minutes.  set_rtc() has to be
+ * called as close as possible to 500 ms before the new second
+ * starts.
+ */
+static inline void do_set_rtc(void)
+{
+        if (time_status & STA_UNSYNC || set_rtc == NULL)
+                return;
+
+//FIXME - timespec.tv_sec is a time_t not unsigned long
+        if (next_rtc_update &&
+            time_before((unsigned long)xtime.tv_sec, next_rtc_update))
+                return;
+
+        if (xtime.tv_nsec < 500000000 - ((unsigned) tick_nsec >> 1) &&
+            xtime.tv_nsec >= 500000000 + ((unsigned) tick_nsec >> 1))
+                return;
+
+        if (set_rtc())
+                /*
+                 * rtc update failed.  Try again in 60s
+                 */
+                next_rtc_update = xtime.tv_sec + 60;
+        else
+                next_rtc_update = xtime.tv_sec + 660;
+}
+
+#define do_leds()
+
+void do_gettimeofday(struct timeval *tv)
+{
+        unsigned long flags;
+        unsigned long seq;
+        unsigned long usec, sec, lost;
+
+        do {
+                seq = read_seqbegin_irqsave(&xtime_lock, flags);
+                usec = gettimeoffset();
+
+                lost = jiffies - wall_jiffies;
+                if (lost)
+                        usec += lost * USECS_PER_JIFFY;
+
+                sec = xtime.tv_sec;
+                usec += xtime.tv_nsec / 1000;
+        } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
+
+        /* usec may have gone up a lot: be safe */
+        while (usec >= 1000000) {
+                usec -= 1000000;
+                sec++;
+        }
+
+        tv->tv_sec = sec;
+        tv->tv_usec = usec;
+}
+
+EXPORT_SYMBOL(do_gettimeofday);
+
+int do_settimeofday(struct timespec *tv)
+{
+        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
+         * done, and then undo it!
+         */
+        tv->tv_nsec -= 1000 * (gettimeoffset() +
+                        (jiffies - wall_jiffies) * USECS_PER_JIFFY);
+
+        while (tv->tv_nsec < 0) {
+                tv->tv_nsec += NSEC_PER_SEC;
+                tv->tv_sec--;
+        }
+
+        xtime.tv_sec = tv->tv_sec;
+        xtime.tv_nsec = tv->tv_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);
+
+static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+        do_timer(regs);
+#ifndef CONFIG_SMP
+        update_process_times(user_mode(regs));
+#endif
+        do_set_rtc(); //FIME - EVERY timer IRQ?
+        profile_tick(CPU_PROFILING, regs);
+        return IRQ_HANDLED; //FIXME - is this right?
+}
+
+static struct irqaction timer_irq = {
+        .name   = "timer",
+        .flags  = SA_INTERRUPT,
+        .handler = timer_interrupt,
+};
+
+extern void ioctime_init(void);
+
+/*
+ * Set up timer interrupt.
+ */
+void __init time_init(void)
+{
+        ioc_writeb(LATCH & 255, IOC_T0LTCHL);
+        ioc_writeb(LATCH >> 8, IOC_T0LTCHH);
+        ioc_writeb(0, IOC_T0GO);
+
+
+        setup_irq(IRQ_TIMER, &timer_irq);
+}
+