1 files changed, 88 insertions, 0 deletions
diff --git a/arch/arm/mach-ns9xxx/time.c b/arch/arm/mach-ns9xxx/time.c
new file mode 100644
index 000000000000..eec05f18714a
--- /dev/null
+++ b/arch/arm/mach-ns9xxx/time.c
@@ -0,0 +1,88 @@
+/*
+ * arch/arm/mach-ns9xxx/time.c
+ *
+ * Copyright (C) 2006 by Digi International Inc.
+ * All rights reserved.
+ *
+ * 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.
+ */
+#include <linux/jiffies.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <asm/arch-ns9xxx/regs-sys.h>
+#include <asm/arch-ns9xxx/clock.h>
+#include <asm/arch-ns9xxx/irqs.h>
+#include <asm/arch/system.h>
+#include "generic.h"
+
+#define TIMERCLOCKSELECT 64
+
+static u32 usecs_per_tick;
+
+static irqreturn_t
+ns9xxx_timer_interrupt(int irq, void *dev_id)
+{
+	write_seqlock(&xtime_lock);
+	timer_tick();
+	write_sequnlock(&xtime_lock);
+
+	return IRQ_HANDLED;
+}
+
+static unsigned long ns9xxx_timer_gettimeoffset(void)
+{
+	/* return the microseconds which have passed since the last interrupt
+	 * was _serviced_.  That is, if an interrupt is pending or the counter
+	 * reloads, return one periode more. */
+
+	u32 counter1 = SYS_TR(0);
+	int pending = SYS_ISR & (1 << IRQ_TIMER0);
+	u32 counter2 = SYS_TR(0);
+	u32 elapsed;
+
+	if (pending || counter2 > counter1)
+		elapsed = 2 * SYS_TRC(0) - counter2;
+	else
+		elapsed = SYS_TRC(0) - counter1;
+
+	return (elapsed * usecs_per_tick) >> 16;
+
+}
+
+static struct irqaction ns9xxx_timer_irq = {
+	.name = "NS9xxx Timer Tick",
+	.flags = IRQF_DISABLED | IRQF_TIMER,
+	.handler = ns9xxx_timer_interrupt,
+};
+
+static void __init ns9xxx_timer_init(void)
+{
+	int tc;
+
+	usecs_per_tick =
+		SH_DIV(1000000 * TIMERCLOCKSELECT, ns9xxx_cpuclock(), 16);
+
+	/* disable timer */
+	if ((tc = SYS_TC(0)) & SYS_TCx_TEN)
+		SYS_TC(0) = tc & ~SYS_TCx_TEN;
+
+	SYS_TRC(0) = SH_DIV(ns9xxx_cpuclock(), (TIMERCLOCKSELECT * HZ), 0);
+
+	REGSET(tc, SYS_TCx, TEN, EN);
+	REGSET(tc, SYS_TCx, TLCS, DIV64); /* This must match TIMERCLOCKSELECT */
+	REGSET(tc, SYS_TCx, INTS, EN);
+	REGSET(tc, SYS_TCx, UDS, DOWN);
+	REGSET(tc, SYS_TCx, TDBG, STOP);
+	REGSET(tc, SYS_TCx, TSZ, 32);
+	REGSET(tc, SYS_TCx, REN, EN);
+	SYS_TC(0) = tc;
+
+	setup_irq(IRQ_TIMER0, &ns9xxx_timer_irq);
+}
+
+struct sys_timer ns9xxx_timer = {
+	.init = ns9xxx_timer_init,
+	.offset = ns9xxx_timer_gettimeoffset,
+};