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 00000000000..ff492e3b345
--- /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
+}