1 files changed, 129 insertions, 0 deletions

diff --git a/arch/mn10300/kernel/time.c b/arch/mn10300/kernel/time.c
new file mode 100644
index 000000000000..ff492e3b3457
--- /dev/null
+++ b/arch/mn10300/kernel/time.c
@@ -0,0 +1,129 @@
+/* MN10300 Low level time management
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ * - Derived from arch/i386/kernel/time.c
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/profile.h>
+#include <asm/irq.h>
+#include <asm/div64.h>
+#include <asm/processor.h>
+#include <asm/intctl-regs.h>
+#include <asm/rtc.h>
+
+#ifdef CONFIG_MN10300_RTC
+unsigned long mn10300_ioclk;            /* system I/O clock frequency */
+unsigned long mn10300_iobclk;           /* system I/O clock frequency */
+unsigned long mn10300_tsc_per_HZ;       /* number of ioclks per jiffy */
+#endif /* CONFIG_MN10300_RTC */
+
+static unsigned long mn10300_last_tsc;  /* time-stamp counter at last time
+                                         * interrupt occurred */
+
+static irqreturn_t timer_interrupt(int irq, void *dev_id);
+
+static struct irqaction timer_irq = {
+        .handler        = timer_interrupt,
+        .flags          = IRQF_DISABLED | IRQF_SHARED | IRQF_TIMER,
+        .mask           = CPU_MASK_NONE,
+        .name           = "timer",
+};
+
+/*
+ * scheduler clock - returns current time in nanosec units.
+ */
+unsigned long long sched_clock(void)
+{
+        union {
+                unsigned long long l;
+                u32 w[2];
+        } quot;
+
+        quot.w[0] = mn10300_last_tsc - get_cycles();
+        quot.w[1] = 1000000000;
+
+        asm("mulu %2,%3,%0,%1"
+            : "=r"(quot.w[1]), "=r"(quot.w[0])
+            : "0"(quot.w[1]), "1"(quot.w[0])
+            : "cc");
+
+        do_div(quot.l, MN10300_TSCCLK);
+
+        return quot.l;
+}
+
+/*
+ * advance the kernel's time keeping clocks (xtime and jiffies)
+ * - we use Timer 0 & 1 cascaded as a clock to nudge us the next time
+ *   there's a need to update
+ */
+static irqreturn_t timer_interrupt(int irq, void *dev_id)
+{
+        unsigned tsc, elapse;
+
+        write_seqlock(&xtime_lock);
+
+        while (tsc = get_cycles(),
+               elapse = mn10300_last_tsc - tsc, /* time elapsed since last
+                                                 * tick */
+               elapse > MN10300_TSC_PER_HZ
+               ) {
+                mn10300_last_tsc -= MN10300_TSC_PER_HZ;
+
+                /* advance the kernel's time tracking system */
+                profile_tick(CPU_PROFILING);
+                do_timer(1);
+                update_process_times(user_mode(get_irq_regs()));
+                check_rtc_time();
+        }
+
+        write_sequnlock(&xtime_lock);
+        return IRQ_HANDLED;
+}
+
+/*
+ * initialise the various timers used by the main part of the kernel
+ */
+void __init time_init(void)
+{
+        /* we need the prescalar running to be able to use IOCLK/8
+         * - IOCLK runs at 1/4 (ST5 open) or 1/8 (ST5 closed) internal CPU clock
+         * - IOCLK runs at Fosc rate (crystal speed)
+         */
+        TMPSCNT |= TMPSCNT_ENABLE;
+
+        startup_timestamp_counter();
+
+        printk(KERN_INFO
+               "timestamp counter I/O clock running at %lu.%02lu"
+               " (calibrated against RTC)\n",
+               MN10300_TSCCLK / 1000000, (MN10300_TSCCLK / 10000) % 100);
+
+        xtime.tv_sec = get_initial_rtc_time();
+        xtime.tv_nsec = 0;
+
+        mn10300_last_tsc = TMTSCBC;
+
+        /* use timer 0 & 1 cascaded to tick at as close to HZ as possible */
+        setup_irq(TMJCIRQ, &timer_irq);
+
+        set_intr_level(TMJCIRQ, TMJCICR_LEVEL);
+
+        startup_jiffies_counter();
+
+#ifdef CONFIG_MN10300_WD_TIMER
+        /* start the watchdog timer */
+        watchdog_go();
+#endif
+}