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-rw-r--r--arch/arm/mach-orion/time.c181
1 files changed, 181 insertions, 0 deletions
diff --git a/arch/arm/mach-orion/time.c b/arch/arm/mach-orion/time.c
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+/*
+ * arch/arm/mach-orion/time.c
+ *
+ * Core time functions for Marvell Orion System On Chip
+ *
+ * Maintainer: Tzachi Perelstein <tzachi@marvell.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <asm/mach/time.h>
+#include <asm/arch/orion.h>
+#include "common.h"
+
+/*
+ * Timer0: clock_event_device, Tick.
+ * Timer1: clocksource, Free running.
+ * WatchDog: Not used.
+ *
+ * Timers are counting down.
+ */
+#define CLOCKEVENT 0
+#define CLOCKSOURCE 1
+
+/*
+ * Timers bits
+ */
+#define BRIDGE_INT_TIMER(x) (1 << ((x) + 1))
+#define TIMER_EN(x) (1 << ((x) * 2))
+#define TIMER_RELOAD_EN(x) (1 << (((x) * 2) + 1))
+#define BRIDGE_INT_TIMER_WD (1 << 3)
+#define TIMER_WD_EN (1 << 4)
+#define TIMER_WD_RELOAD_EN (1 << 5)
+
+static cycle_t orion_clksrc_read(void)
+{
+ return (0xffffffff - orion_read(TIMER_VAL(CLOCKSOURCE)));
+}
+
+static struct clocksource orion_clksrc = {
+ .name = "orion_clocksource",
+ .shift = 20,
+ .rating = 300,
+ .read = orion_clksrc_read,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int
+orion_clkevt_next_event(unsigned long delta, struct clock_event_device *dev)
+{
+ unsigned long flags;
+
+ if (delta == 0)
+ return -ETIME;
+
+ local_irq_save(flags);
+
+ /*
+ * Clear and enable timer interrupt bit
+ */
+ orion_write(BRIDGE_CAUSE, ~BRIDGE_INT_TIMER(CLOCKEVENT));
+ orion_setbits(BRIDGE_MASK, BRIDGE_INT_TIMER(CLOCKEVENT));
+
+ /*
+ * Setup new timer value
+ */
+ orion_write(TIMER_VAL(CLOCKEVENT), delta);
+
+ /*
+ * Disable auto reload and kickoff the timer
+ */
+ orion_clrbits(TIMER_CTRL, TIMER_RELOAD_EN(CLOCKEVENT));
+ orion_setbits(TIMER_CTRL, TIMER_EN(CLOCKEVENT));
+
+ local_irq_restore(flags);
+
+ return 0;
+}
+
+static void
+orion_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+
+ if (mode == CLOCK_EVT_MODE_PERIODIC) {
+ /*
+ * Setup latch cycles in timer and enable reload interrupt.
+ */
+ orion_write(TIMER_VAL_RELOAD(CLOCKEVENT), LATCH);
+ orion_write(TIMER_VAL(CLOCKEVENT), LATCH);
+ orion_setbits(BRIDGE_MASK, BRIDGE_INT_TIMER(CLOCKEVENT));
+ orion_setbits(TIMER_CTRL, TIMER_RELOAD_EN(CLOCKEVENT) |
+ TIMER_EN(CLOCKEVENT));
+ } else {
+ /*
+ * Disable timer and interrupt
+ */
+ orion_clrbits(BRIDGE_MASK, BRIDGE_INT_TIMER(CLOCKEVENT));
+ orion_write(BRIDGE_CAUSE, ~BRIDGE_INT_TIMER(CLOCKEVENT));
+ orion_clrbits(TIMER_CTRL, TIMER_RELOAD_EN(CLOCKEVENT) |
+ TIMER_EN(CLOCKEVENT));
+ }
+
+ local_irq_restore(flags);
+}
+
+static struct clock_event_device orion_clkevt = {
+ .name = "orion_tick",
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ .shift = 32,
+ .rating = 300,
+ .cpumask = CPU_MASK_CPU0,
+ .set_next_event = orion_clkevt_next_event,
+ .set_mode = orion_clkevt_mode,
+};
+
+static irqreturn_t orion_timer_interrupt(int irq, void *dev_id)
+{
+ /*
+ * Clear cause bit and do event
+ */
+ orion_write(BRIDGE_CAUSE, ~BRIDGE_INT_TIMER(CLOCKEVENT));
+ orion_clkevt.event_handler(&orion_clkevt);
+ return IRQ_HANDLED;
+}
+
+static struct irqaction orion_timer_irq = {
+ .name = "orion_tick",
+ .flags = IRQF_DISABLED | IRQF_TIMER,
+ .handler = orion_timer_interrupt
+};
+
+static void orion_timer_init(void)
+{
+ /*
+ * Setup clocksource free running timer (no interrupt on reload)
+ */
+ orion_write(TIMER_VAL(CLOCKSOURCE), 0xffffffff);
+ orion_write(TIMER_VAL_RELOAD(CLOCKSOURCE), 0xffffffff);
+ orion_clrbits(BRIDGE_MASK, BRIDGE_INT_TIMER(CLOCKSOURCE));
+ orion_setbits(TIMER_CTRL, TIMER_RELOAD_EN(CLOCKSOURCE) |
+ TIMER_EN(CLOCKSOURCE));
+
+ /*
+ * Register clocksource
+ */
+ orion_clksrc.mult =
+ clocksource_hz2mult(CLOCK_TICK_RATE, orion_clksrc.shift);
+
+ clocksource_register(&orion_clksrc);
+
+ /*
+ * Connect and enable tick handler
+ */
+ setup_irq(IRQ_ORION_BRIDGE, &orion_timer_irq);
+
+ /*
+ * Register clockevent
+ */
+ orion_clkevt.mult =
+ div_sc(CLOCK_TICK_RATE, NSEC_PER_SEC, orion_clkevt.shift);
+ orion_clkevt.max_delta_ns =
+ clockevent_delta2ns(0xfffffffe, &orion_clkevt);
+ orion_clkevt.min_delta_ns =
+ clockevent_delta2ns(1, &orion_clkevt);
+
+ clockevents_register_device(&orion_clkevt);
+}
+
+struct sys_timer orion_timer = {
+ .init = orion_timer_init,
+};