MN10300: Generic time support

Implement generic time support for MN10300.

Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 131 insertions, 0 deletions

diff --git a/arch/mn10300/kernel/cevt-mn10300.c b/arch/mn10300/kernel/cevt-mn10300.c
new file mode 100644
index 00000000000..d4cb535bf78
--- /dev/null
+++ b/arch/mn10300/kernel/cevt-mn10300.c
@@ -0,0 +1,131 @@
+/* MN10300 clockevents
+ *
+ * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved.
+ * Written by Mark Salter (msalter@redhat.com)
+ *
+ * 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/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/percpu.h>
+#include <linux/smp.h>
+#include <asm/timex.h>
+#include "internal.h"
+
+#ifdef CONFIG_SMP
+#if (CONFIG_NR_CPUS > 2) && !defined(CONFIG_GEENERIC_CLOCKEVENTS_BROADCAST)
+#error "This doesn't scale well! Need per-core local timers."
+#endif
+#else /* CONFIG_SMP */
+#define stop_jiffies_counter1()
+#define reload_jiffies_counter1(x)
+#define TMJC1IRQ TMJCIRQ
+#endif
+
+
+static int next_event(unsigned long delta,
+		      struct clock_event_device *evt)
+{
+	unsigned int cpu = smp_processor_id();
+
+	if (cpu == 0) {
+		stop_jiffies_counter();
+		reload_jiffies_counter(delta - 1);
+	} else {
+		stop_jiffies_counter1();
+		reload_jiffies_counter1(delta - 1);
+	}
+	return 0;
+}
+
+static void set_clock_mode(enum clock_event_mode mode,
+			   struct clock_event_device *evt)
+{
+	/* Nothing to do ...  */
+}
+
+static DEFINE_PER_CPU(struct clock_event_device, mn10300_clockevent_device);
+static DEFINE_PER_CPU(struct irqaction, timer_irq);
+
+static irqreturn_t timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *cd;
+	unsigned int cpu = smp_processor_id();
+
+	if (cpu == 0)
+		stop_jiffies_counter();
+	else
+		stop_jiffies_counter1();
+
+	cd = &per_cpu(mn10300_clockevent_device, cpu);
+	cd->event_handler(cd);
+
+	return IRQ_HANDLED;
+}
+
+static void event_handler(struct clock_event_device *dev)
+{
+}
+
+int __init init_clockevents(void)
+{
+	struct clock_event_device *cd;
+	struct irqaction *iact;
+	unsigned int cpu = smp_processor_id();
+
+	cd = &per_cpu(mn10300_clockevent_device, cpu);
+
+	if (cpu == 0) {
+		stop_jiffies_counter();
+		cd->irq	= TMJCIRQ;
+	} else {
+		stop_jiffies_counter1();
+		cd->irq	= TMJC1IRQ;
+	}
+
+	cd->name		= "Timestamp";
+	cd->features		= CLOCK_EVT_FEAT_ONESHOT;
+
+	/* Calculate the min / max delta */
+	clockevent_set_clock(cd, MN10300_JCCLK);
+
+	cd->max_delta_ns	= clockevent_delta2ns(TMJCBR_MAX, cd);
+	cd->min_delta_ns	= clockevent_delta2ns(100, cd);
+
+	cd->rating		= 200;
+	cd->cpumask		= cpumask_of(smp_processor_id());
+	cd->set_mode		= set_clock_mode;
+	cd->event_handler	= event_handler;
+	cd->set_next_event	= next_event;
+
+	iact = &per_cpu(timer_irq, cpu);
+	iact->flags = IRQF_DISABLED | IRQF_SHARED | IRQF_TIMER;
+	iact->handler = timer_interrupt;
+
+	clockevents_register_device(cd);
+
+#if defined(CONFIG_SMP) && !defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
+	/* setup timer irq affinity so it only runs on this cpu */
+	{
+		struct irq_desc *desc;
+		desc = irq_to_desc(cd->irq);
+		cpumask_copy(desc->affinity, cpumask_of(cpu));
+		iact->flags |= IRQF_NOBALANCING;
+	}
+#endif
+
+	if (cpu == 0) {
+		reload_jiffies_counter(MN10300_JC_PER_HZ - 1);
+		iact->name = "CPU0 Timer";
+	} else {
+		reload_jiffies_counter1(MN10300_JC_PER_HZ - 1);
+		iact->name = "CPU1 Timer";
+	}
+
+	setup_jiffies_interrupt(cd->irq, iact);
+
+	return 0;
+}