1 files changed, 101 insertions, 0 deletions

diff --git a/arch/arm/mach-imx/time.c b/arch/arm/mach-imx/time.c
new file mode 100644
index 000000000000..11f1e56c36bc
--- /dev/null
+++ b/arch/arm/mach-imx/time.c
@@ -0,0 +1,101 @@
+/*
+ *  linux/arch/arm/mach-imx/time.c
+ *
+ *  Copyright (C) 2000-2001 Deep Blue Solutions
+ *  Copyright (C) 2002 Shane Nay (shane@minirl.com)
+ *
+ * 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/config.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/time.h>
+
+#include <asm/hardware.h>
+#include <asm/io.h>
+#include <asm/leds.h>
+#include <asm/irq.h>
+#include <asm/mach/time.h>
+
+/* Use timer 1 as system timer */
+#define TIMER_BASE IMX_TIM1_BASE
+
+/*
+ * Returns number of us since last clock interrupt.  Note that interrupts
+ * will have been disabled by do_gettimeoffset()
+ */
+static unsigned long imx_gettimeoffset(void)
+{
+        unsigned long ticks;
+
+        /*
+         * Get the current number of ticks.  Note that there is a race
+         * condition between us reading the timer and checking for
+         * an interrupt.  We get around this by ensuring that the
+         * counter has not reloaded between our two reads.
+         */
+        ticks = IMX_TCN(TIMER_BASE);
+
+        /*
+         * Interrupt pending?  If so, we've reloaded once already.
+         */
+        if (IMX_TSTAT(TIMER_BASE) & TSTAT_COMP)
+                ticks += LATCH;
+
+        /*
+         * Convert the ticks to usecs
+         */
+        return (1000000 / CLK32) * ticks;
+}
+
+/*
+ * IRQ handler for the timer
+ */
+static irqreturn_t
+imx_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+        write_seqlock(&xtime_lock);
+
+        /* clear the interrupt */
+        if (IMX_TSTAT(TIMER_BASE))
+                IMX_TSTAT(TIMER_BASE) = 0;
+
+        timer_tick(regs);
+        write_sequnlock(&xtime_lock);
+
+        return IRQ_HANDLED;
+}
+
+static struct irqaction imx_timer_irq = {
+        .name           = "i.MX Timer Tick",
+        .flags          = SA_INTERRUPT,
+        .handler        = imx_timer_interrupt
+};
+
+/*
+ * Set up timer interrupt, and return the current time in seconds.
+ */
+static void __init imx_timer_init(void)
+{
+        /*
+         * Initialise to a known state (all timers off, and timing reset)
+         */
+        IMX_TCTL(TIMER_BASE) = 0;
+        IMX_TPRER(TIMER_BASE) = 0;
+        IMX_TCMP(TIMER_BASE) = LATCH - 1;
+        IMX_TCTL(TIMER_BASE) = TCTL_CLK_32 | TCTL_IRQEN | TCTL_TEN;
+
+        /*
+         * Make irqs happen for the system timer
+         */
+        setup_irq(TIM1_INT, &imx_timer_irq);
+}
+
+struct sys_timer imx_timer = {
+        .init           = imx_timer_init,
+        .offset         = imx_gettimeoffset,
+};