1 files changed, 199 insertions, 0 deletions

diff --git a/arch/arm/mach-mmp/time.c b/arch/arm/mach-mmp/time.c
new file mode 100644
index 000000000000..b03a6eda7419
--- /dev/null
+++ b/arch/arm/mach-mmp/time.c
@@ -0,0 +1,199 @@
+/*
+ * linux/arch/arm/mach-mmp/time.c
+ *
+ *   Support for clocksource and clockevents
+ *
+ * Copyright (C) 2008 Marvell International Ltd.
+ * All rights reserved.
+ *
+ *   2008-04-11: Jason Chagas <Jason.chagas@marvell.com>
+ *   2008-10-08: Bin Yang <bin.yang@marvell.com>
+ *
+ * The timers module actually includes three timers, each timer with upto
+ * three match comparators. Timer #0 is used here in free-running mode as
+ * the clock source, and match comparator #1 used as clock event device.
+ *
+ * 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/init.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/clockchips.h>
+
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/sched.h>
+#include <linux/cnt32_to_63.h>
+
+#include <mach/addr-map.h>
+#include <mach/regs-timers.h>
+#include <mach/irqs.h>
+
+#include "clock.h"
+
+#define TIMERS_VIRT_BASE        TIMERS1_VIRT_BASE
+
+#define MAX_DELTA               (0xfffffffe)
+#define MIN_DELTA               (16)
+
+#define TCR2NS_SCALE_FACTOR     10
+
+static unsigned long tcr2ns_scale;
+
+static void __init set_tcr2ns_scale(unsigned long tcr_rate)
+{
+        unsigned long long v = 1000000000ULL << TCR2NS_SCALE_FACTOR;
+        do_div(v, tcr_rate);
+        tcr2ns_scale = v;
+        /*
+         * We want an even value to automatically clear the top bit
+         * returned by cnt32_to_63() without an additional run time
+         * instruction. So if the LSB is 1 then round it up.
+         */
+        if (tcr2ns_scale & 1)
+                tcr2ns_scale++;
+}
+
+/*
+ * FIXME: the timer needs some delay to stablize the counter capture
+ */
+static inline uint32_t timer_read(void)
+{
+        int delay = 100;
+
+        __raw_writel(1, TIMERS_VIRT_BASE + TMR_CVWR(0));
+
+        while (delay--)
+                cpu_relax();
+
+        return __raw_readl(TIMERS_VIRT_BASE + TMR_CVWR(0));
+}
+
+unsigned long long sched_clock(void)
+{
+        unsigned long long v = cnt32_to_63(timer_read());
+        return (v * tcr2ns_scale) >> TCR2NS_SCALE_FACTOR;
+}
+
+static irqreturn_t timer_interrupt(int irq, void *dev_id)
+{
+        struct clock_event_device *c = dev_id;
+
+        /* disable and clear pending interrupt status */
+        __raw_writel(0x0, TIMERS_VIRT_BASE + TMR_IER(0));
+        __raw_writel(0x1, TIMERS_VIRT_BASE + TMR_ICR(0));
+        c->event_handler(c);
+        return IRQ_HANDLED;
+}
+
+static int timer_set_next_event(unsigned long delta,
+                                struct clock_event_device *dev)
+{
+        unsigned long flags, next;
+
+        local_irq_save(flags);
+
+        /* clear pending interrupt status and enable */
+        __raw_writel(0x01, TIMERS_VIRT_BASE + TMR_ICR(0));
+        __raw_writel(0x01, TIMERS_VIRT_BASE + TMR_IER(0));
+
+        next = timer_read() + delta;
+        __raw_writel(next, TIMERS_VIRT_BASE + TMR_TN_MM(0, 0));
+
+        local_irq_restore(flags);
+        return 0;
+}
+
+static void timer_set_mode(enum clock_event_mode mode,
+                           struct clock_event_device *dev)
+{
+        unsigned long flags;
+
+        local_irq_save(flags);
+        switch (mode) {
+        case CLOCK_EVT_MODE_ONESHOT:
+        case CLOCK_EVT_MODE_UNUSED:
+        case CLOCK_EVT_MODE_SHUTDOWN:
+                /* disable the matching interrupt */
+                __raw_writel(0x00, TIMERS_VIRT_BASE + TMR_IER(0));
+                break;
+        case CLOCK_EVT_MODE_RESUME:
+        case CLOCK_EVT_MODE_PERIODIC:
+                break;
+        }
+        local_irq_restore(flags);
+}
+
+static struct clock_event_device ckevt = {
+        .name           = "clockevent",
+        .features       = CLOCK_EVT_FEAT_ONESHOT,
+        .shift          = 32,
+        .rating         = 200,
+        .set_next_event = timer_set_next_event,
+        .set_mode       = timer_set_mode,
+};
+
+static cycle_t clksrc_read(void)
+{
+        return timer_read();
+}
+
+static struct clocksource cksrc = {
+        .name           = "clocksource",
+        .shift          = 20,
+        .rating         = 200,
+        .read           = clksrc_read,
+        .mask           = CLOCKSOURCE_MASK(32),
+        .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static void __init timer_config(void)
+{
+        uint32_t ccr = __raw_readl(TIMERS_VIRT_BASE + TMR_CCR);
+        uint32_t cer = __raw_readl(TIMERS_VIRT_BASE + TMR_CER);
+        uint32_t cmr = __raw_readl(TIMERS_VIRT_BASE + TMR_CMR);
+
+        __raw_writel(cer & ~0x1, TIMERS_VIRT_BASE + TMR_CER); /* disable */
+
+        ccr &= TMR_CCR_CS_0(0x3);
+        __raw_writel(ccr, TIMERS_VIRT_BASE + TMR_CCR);
+
+        /* free-running mode */
+        __raw_writel(cmr | 0x01, TIMERS_VIRT_BASE + TMR_CMR);
+
+        __raw_writel(0x0, TIMERS_VIRT_BASE + TMR_PLCR(0)); /* free-running */
+        __raw_writel(0x7, TIMERS_VIRT_BASE + TMR_ICR(0));  /* clear status */
+        __raw_writel(0x0, TIMERS_VIRT_BASE + TMR_IER(0));
+
+        /* enable timer counter */
+        __raw_writel(cer | 0x01, TIMERS_VIRT_BASE + TMR_CER);
+}
+
+static struct irqaction timer_irq = {
+        .name           = "timer",
+        .flags          = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
+        .handler        = timer_interrupt,
+        .dev_id         = &ckevt,
+};
+
+void __init timer_init(int irq)
+{
+        timer_config();
+
+        set_tcr2ns_scale(CLOCK_TICK_RATE);
+
+        ckevt.mult = div_sc(CLOCK_TICK_RATE, NSEC_PER_SEC, ckevt.shift);
+        ckevt.max_delta_ns = clockevent_delta2ns(MAX_DELTA, &ckevt);
+        ckevt.min_delta_ns = clockevent_delta2ns(MIN_DELTA, &ckevt);
+        ckevt.cpumask = cpumask_of(0);
+
+        cksrc.mult = clocksource_hz2mult(CLOCK_TICK_RATE, cksrc.shift);
+
+        setup_irq(irq, &timer_irq);
+
+        clocksource_register(&cksrc);
+        clockevents_register_device(&ckevt);
+}