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>

1 files changed, 90 insertions, 0 deletions

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();