From a331ce63c85080f554e0a19fc4189a520c65267b Mon Sep 17 00:00:00 2001
From: Andrew Bresticker <abrestic@chromium.org>
Date: Mon, 20 Oct 2014 12:03:59 -0700
Subject: clocksource: mips-gic: Combine with GIC clockevent driver

Combine the GIC clocksource driver with the GIC clockevent driver from
arch/mips/kernel/cevt-gic.c and remove the clockevent driver's separate
Kconfig symbol.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8132/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 drivers/clocksource/mips-gic-timer.c | 90 ++++++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)

(limited to 'drivers/clocksource/mips-gic-timer.c')

diff --git a/drivers/clocksource/mips-gic-timer.c b/drivers/clocksource/mips-gic-timer.c
index 0bf28e6aca7a..3cf5912c4054 100644
--- a/drivers/clocksource/mips-gic-timer.c
+++ b/drivers/clocksource/mips-gic-timer.c
@@ -5,10 +5,100 @@
  *
  * Copyright (C) 2012 MIPS Technologies, Inc.  All rights reserved.
  */
+#include <linux/clockchips.h>
 #include <linux/init.h>
+#include <linux/interrupt.h>
 #include <linux/irqchip/mips-gic.h>
+#include <linux/percpu.h>
+#include <linux/smp.h>
 #include <linux/time.h>
 
+#include <asm/time.h>
+
+DEFINE_PER_CPU(struct clock_event_device, gic_clockevent_device);
+int gic_timer_irq_installed;
+
+static int gic_next_event(unsigned long delta, struct clock_event_device *evt)
+{
+	u64 cnt;
+	int res;
+
+	cnt = gic_read_count();
+	cnt += (u64)delta;
+	gic_write_cpu_compare(cnt, cpumask_first(evt->cpumask));
+	res = ((int)(gic_read_count() - cnt) >= 0) ? -ETIME : 0;
+	return res;
+}
+
+void gic_set_clock_mode(enum clock_event_mode mode,
+				struct clock_event_device *evt)
+{
+	/* Nothing to do ...  */
+}
+
+irqreturn_t gic_compare_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *cd;
+	int cpu = smp_processor_id();
+
+	gic_write_compare(gic_read_compare());
+	cd = &per_cpu(gic_clockevent_device, cpu);
+	cd->event_handler(cd);
+	return IRQ_HANDLED;
+}
+
+struct irqaction gic_compare_irqaction = {
+	.handler = gic_compare_interrupt,
+	.flags = IRQF_PERCPU | IRQF_TIMER,
+	.name = "timer",
+};
+
+void gic_event_handler(struct clock_event_device *dev)
+{
+}
+
+int gic_clockevent_init(void)
+{
+	unsigned int cpu = smp_processor_id();
+	struct clock_event_device *cd;
+	unsigned int irq;
+
+	if (!cpu_has_counter || !gic_frequency)
+		return -ENXIO;
+
+	irq = MIPS_GIC_IRQ_BASE + GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_COMPARE);
+
+	cd = &per_cpu(gic_clockevent_device, cpu);
+
+	cd->name		= "MIPS GIC";
+	cd->features		= CLOCK_EVT_FEAT_ONESHOT |
+				  CLOCK_EVT_FEAT_C3STOP;
+
+	clockevent_set_clock(cd, gic_frequency);
+
+	/* Calculate the min / max delta */
+	cd->max_delta_ns	= clockevent_delta2ns(0x7fffffff, cd);
+	cd->min_delta_ns	= clockevent_delta2ns(0x300, cd);
+
+	cd->rating		= 300;
+	cd->irq			= irq;
+	cd->cpumask		= cpumask_of(cpu);
+	cd->set_next_event	= gic_next_event;
+	cd->set_mode		= gic_set_clock_mode;
+	cd->event_handler	= gic_event_handler;
+
+	clockevents_register_device(cd);
+
+	if (!gic_timer_irq_installed) {
+		setup_percpu_irq(irq, &gic_compare_irqaction);
+		gic_timer_irq_installed = 1;
+	}
+
+	enable_percpu_irq(irq, IRQ_TYPE_NONE);
+
+	return 0;
+}
+
 static cycle_t gic_hpt_read(struct clocksource *cs)
 {
 	return gic_read_count();
-- 
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