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/Kconfig b/arch/mips/Kconfig
index 4b62305..44e29b64 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -912,6 +912,9 @@
config CEVT_R4K
bool
+config CEVT_GIC
+ bool
+
config CEVT_SB1250
bool
@@ -1819,6 +1822,15 @@
The page size is not necessarily 4KB. Keep this in mind
when choosing a value for this option.
+config CEVT_GIC
+ bool "Use GIC global counter for clock events"
+ depends on IRQ_GIC && !(MIPS_SEAD3 || MIPS_MT_SMTC)
+ help
+ Use the GIC global counter for the clock events. The R4K clock
+ event driver is always present, so if the platform ends up not
+ detecting a GIC, it will fall back to the R4K timer for the
+ generation of clock events.
+
config BOARD_SCACHE
bool
diff --git a/arch/mips/include/asm/gic.h b/arch/mips/include/asm/gic.h
index 398cf54..7153b32 100644
--- a/arch/mips/include/asm/gic.h
+++ b/arch/mips/include/asm/gic.h
@@ -202,7 +202,7 @@
#define GIC_VPE_WD_COUNT0_OFS 0x0094
#define GIC_VPE_WD_INITIAL0_OFS 0x0098
#define GIC_VPE_COMPARE_LO_OFS 0x00a0
-#define GIC_VPE_COMPARE_HI 0x00a4
+#define GIC_VPE_COMPARE_HI_OFS 0x00a4
#define GIC_VPE_EIC_SHADOW_SET_BASE 0x0100
#define GIC_VPE_EIC_SS(intr) \
@@ -373,7 +373,10 @@
unsigned long gic_addrspace_size, struct gic_intr_map *intrmap,
unsigned int intrmap_size, unsigned int irqbase);
extern void gic_clocksource_init(unsigned int);
+extern unsigned int gic_compare_int (void);
extern cycle_t gic_read_count(void);
+extern cycle_t gic_read_compare(void);
+extern void gic_write_compare(cycle_t cnt);
extern void gic_send_ipi(unsigned int intr);
extern unsigned int plat_ipi_call_int_xlate(unsigned int);
extern unsigned int plat_ipi_resched_int_xlate(unsigned int);
diff --git a/arch/mips/include/asm/time.h b/arch/mips/include/asm/time.h
index 4784218..2d7b9df 100644
--- a/arch/mips/include/asm/time.h
+++ b/arch/mips/include/asm/time.h
@@ -53,11 +53,14 @@
extern unsigned int __weak get_c0_compare_int(void);
extern int r4k_clockevent_init(void);
extern int smtc_clockevent_init(void);
+extern int gic_clockevent_init(void);
static inline int mips_clockevent_init(void)
{
#ifdef CONFIG_MIPS_MT_SMTC
return smtc_clockevent_init();
+#elif defined(CONFIG_CEVT_GIC)
+ return (gic_clockevent_init() | r4k_clockevent_init());
#elif defined(CONFIG_CEVT_R4K)
return r4k_clockevent_init();
#else
diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
index bab8b16..3d95062 100644
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -19,6 +19,7 @@
obj-$(CONFIG_CEVT_R4K) += cevt-r4k.o
obj-$(CONFIG_MIPS_MT_SMTC) += cevt-smtc.o
obj-$(CONFIG_CEVT_DS1287) += cevt-ds1287.o
+obj-$(CONFIG_CEVT_GIC) += cevt-gic.o
obj-$(CONFIG_CEVT_GT641XX) += cevt-gt641xx.o
obj-$(CONFIG_CEVT_SB1250) += cevt-sb1250.o
obj-$(CONFIG_CEVT_TXX9) += cevt-txx9.o
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;
+}
diff --git a/arch/mips/kernel/cevt-r4k.c b/arch/mips/kernel/cevt-r4k.c
index 0309aef..0613f46 100644
--- a/arch/mips/kernel/cevt-r4k.c
+++ b/arch/mips/kernel/cevt-r4k.c
@@ -72,6 +72,9 @@
/* Clear Count/Compare Interrupt */
write_c0_compare(read_c0_compare());
cd = &per_cpu(mips_clockevent_device, cpu);
+#ifdef CONFIG_CEVT_GIC
+ if (!gic_present)
+#endif
cd->event_handler(cd);
}
@@ -203,6 +206,9 @@
cd->set_mode = mips_set_clock_mode;
cd->event_handler = mips_event_handler;
+#ifdef CONFIG_CEVT_GIC
+ if (!gic_present)
+#endif
clockevents_register_device(cd);
if (cp0_timer_irq_installed)
diff --git a/arch/mips/kernel/irq-gic.c b/arch/mips/kernel/irq-gic.c
index 6a476e1..c01b307 100644
--- a/arch/mips/kernel/irq-gic.c
+++ b/arch/mips/kernel/irq-gic.c
@@ -33,7 +33,7 @@
static struct gic_pending_regs pending_regs[NR_CPUS];
static struct gic_intrmask_regs intrmask_regs[NR_CPUS];
-#ifdef CONFIG_CSRC_GIC
+#if defined(CONFIG_CSRC_GIC) || defined(CONFIG_CEVT_GIC)
cycle_t gic_read_count(void)
{
unsigned int hi, hi2, lo;
@@ -46,6 +46,24 @@
return (((cycle_t) hi) << 32) + lo;
}
+
+void gic_write_compare(cycle_t cnt)
+{
+ GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_COMPARE_HI),
+ (int)(cnt >> 32));
+ GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_COMPARE_LO),
+ (int)(cnt & 0xffffffff));
+}
+
+cycle_t gic_read_compare(void)
+{
+ unsigned int hi, lo;
+
+ GICREAD(GIC_REG(VPE_LOCAL, GIC_VPE_COMPARE_HI), hi);
+ GICREAD(GIC_REG(VPE_LOCAL, GIC_VPE_COMPARE_LO), lo);
+
+ return (((cycle_t) hi) << 32) + lo;
+}
#endif
unsigned int gic_get_timer_pending(void)
@@ -134,6 +152,17 @@
}
}
+unsigned int gic_compare_int(void)
+{
+ unsigned int pending;
+
+ GICREAD(GIC_REG(VPE_LOCAL, GIC_VPE_PEND), pending);
+ if (pending & GIC_VPE_PEND_CMP_MSK)
+ return 1;
+ else
+ return 0;
+}
+
unsigned int gic_get_int(void)
{
unsigned int i;
diff --git a/arch/mips/mti-malta/malta-int.c b/arch/mips/mti-malta/malta-int.c
index 8e840c2..0a1339a 100644
--- a/arch/mips/mti-malta/malta-int.c
+++ b/arch/mips/mti-malta/malta-int.c
@@ -133,6 +133,9 @@
{
int irq;
+ if (gic_compare_int())
+ do_IRQ(MIPS_GIC_IRQ_BASE);
+
irq = gic_get_int();
if (irq < 0)
return; /* interrupt has already been cleared */
