summaryrefslogtreecommitdiffstats
path: root/arch/mips/sgi-ip27/ip27-timer.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--arch/mips/sgi-ip27/ip27-timer.c160
1 files changed, 160 insertions, 0 deletions
diff --git a/arch/mips/sgi-ip27/ip27-timer.c b/arch/mips/sgi-ip27/ip27-timer.c
new file mode 100644
index 000000000..444b5e0e9
--- /dev/null
+++ b/arch/mips/sgi-ip27/ip27-timer.c
@@ -0,0 +1,160 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 1999, 2000, 05, 06 Ralf Baechle (ralf@linux-mips.org)
+ * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
+ */
+#include <linux/bcd.h>
+#include <linux/clockchips.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/sched_clock.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+#include <linux/param.h>
+#include <linux/smp.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <linux/mm.h>
+#include <linux/platform_device.h>
+
+#include <asm/time.h>
+#include <asm/sgialib.h>
+#include <asm/sn/klconfig.h>
+#include <asm/sn/arch.h>
+#include <asm/sn/addrs.h>
+#include <asm/sn/agent.h>
+
+#include "ip27-common.h"
+
+static int rt_next_event(unsigned long delta, struct clock_event_device *evt)
+{
+ unsigned int cpu = smp_processor_id();
+ int slice = cputoslice(cpu);
+ unsigned long cnt;
+
+ cnt = LOCAL_HUB_L(PI_RT_COUNT);
+ cnt += delta;
+ LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt);
+
+ return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0;
+}
+
+static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent);
+static DEFINE_PER_CPU(char [11], hub_rt_name);
+
+static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id)
+{
+ unsigned int cpu = smp_processor_id();
+ struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
+ int slice = cputoslice(cpu);
+
+ /*
+ * Ack
+ */
+ LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0);
+ cd->event_handler(cd);
+
+ return IRQ_HANDLED;
+}
+
+struct irqaction hub_rt_irqaction = {
+ .handler = hub_rt_counter_handler,
+ .percpu_dev_id = &hub_rt_clockevent,
+ .flags = IRQF_PERCPU | IRQF_TIMER,
+ .name = "hub-rt",
+};
+
+/*
+ * This is a hack; we really need to figure these values out dynamically
+ *
+ * Since 800 ns works very well with various HUB frequencies, such as
+ * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time.
+ *
+ * Ralf: which clock rate is used to feed the counter?
+ */
+#define NSEC_PER_CYCLE 800
+#define CYCLES_PER_SEC (NSEC_PER_SEC / NSEC_PER_CYCLE)
+
+void hub_rt_clock_event_init(void)
+{
+ unsigned int cpu = smp_processor_id();
+ struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
+ unsigned char *name = per_cpu(hub_rt_name, cpu);
+
+ sprintf(name, "hub-rt %d", cpu);
+ cd->name = name;
+ cd->features = CLOCK_EVT_FEAT_ONESHOT;
+ clockevent_set_clock(cd, CYCLES_PER_SEC);
+ cd->max_delta_ns = clockevent_delta2ns(0xfffffffffffff, cd);
+ cd->max_delta_ticks = 0xfffffffffffff;
+ cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
+ cd->min_delta_ticks = 0x300;
+ cd->rating = 200;
+ cd->irq = IP27_RT_TIMER_IRQ;
+ cd->cpumask = cpumask_of(cpu);
+ cd->set_next_event = rt_next_event;
+ clockevents_register_device(cd);
+
+ enable_percpu_irq(IP27_RT_TIMER_IRQ, IRQ_TYPE_NONE);
+}
+
+static void __init hub_rt_clock_event_global_init(void)
+{
+ irq_set_handler(IP27_RT_TIMER_IRQ, handle_percpu_devid_irq);
+ irq_set_percpu_devid(IP27_RT_TIMER_IRQ);
+ setup_percpu_irq(IP27_RT_TIMER_IRQ, &hub_rt_irqaction);
+}
+
+static u64 hub_rt_read(struct clocksource *cs)
+{
+ return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
+}
+
+struct clocksource hub_rt_clocksource = {
+ .name = "HUB-RT",
+ .rating = 200,
+ .read = hub_rt_read,
+ .mask = CLOCKSOURCE_MASK(52),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static u64 notrace hub_rt_read_sched_clock(void)
+{
+ return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
+}
+
+static void __init hub_rt_clocksource_init(void)
+{
+ struct clocksource *cs = &hub_rt_clocksource;
+
+ clocksource_register_hz(cs, CYCLES_PER_SEC);
+
+ sched_clock_register(hub_rt_read_sched_clock, 52, CYCLES_PER_SEC);
+}
+
+void __init plat_time_init(void)
+{
+ hub_rt_clocksource_init();
+ hub_rt_clock_event_global_init();
+ hub_rt_clock_event_init();
+}
+
+void hub_rtc_init(nasid_t nasid)
+{
+
+ /*
+ * We only need to initialize the current node.
+ * If this is not the current node then it is a cpuless
+ * node and timeouts will not happen there.
+ */
+ if (get_nasid() == nasid) {
+ LOCAL_HUB_S(PI_RT_EN_A, 1);
+ LOCAL_HUB_S(PI_RT_EN_B, 1);
+ LOCAL_HUB_S(PI_PROF_EN_A, 0);
+ LOCAL_HUB_S(PI_PROF_EN_B, 0);
+ LOCAL_HUB_S(PI_RT_COUNT, 0);
+ LOCAL_HUB_S(PI_RT_PEND_A, 0);
+ LOCAL_HUB_S(PI_RT_PEND_B, 0);
+ }
+}