MIPS: Add new GIC clockevent driver.
Add new clockevent driver that uses the counter present on the MIPS
Global Interrupt Controller.
Signed-off-by: Raghu Gandham <Raghu.Gandham@imgtec.com>
Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
diff --git a/arch/mips/kernel/cevt-gic.c b/arch/mips/kernel/cevt-gic.c
new file mode 100644
index 0000000..730eaf9
--- /dev/null
+++ b/arch/mips/kernel/cevt-gic.c
@@ -0,0 +1,104 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2013 Imagination Technologies Ltd.
+ */
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/percpu.h>
+#include <linux/smp.h>
+#include <linux/irq.h>
+
+#include <asm/time.h>
+#include <asm/gic.h>
+#include <asm/mips-boards/maltaint.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_compare(cnt);
+ 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 __cpuinit 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;
+
+ cd = &per_cpu(gic_clockevent_device, cpu);
+
+ cd->name = "MIPS GIC";
+ cd->features = CLOCK_EVT_FEAT_ONESHOT;
+
+ 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);
+
+ GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_COMPARE_MAP), 0x80000002);
+ GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_SMASK), GIC_VPE_SMASK_CMP_MSK);
+
+ if (gic_timer_irq_installed)
+ return 0;
+
+ gic_timer_irq_installed = 1;
+
+ setup_irq(irq, &gic_compare_irqaction);
+ irq_set_handler(irq, handle_percpu_irq);
+ return 0;
+}