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-rw-r--r--arch/arc/kernel/time.c238
1 files changed, 163 insertions, 75 deletions
diff --git a/arch/arc/kernel/time.c b/arch/arc/kernel/time.c
index 7d9a736fc..4549ab255 100644
--- a/arch/arc/kernel/time.c
+++ b/arch/arc/kernel/time.c
@@ -29,21 +29,16 @@
* which however is currently broken
*/
-#include <linux/spinlock.h>
#include <linux/interrupt.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/kernel.h>
-#include <linux/time.h>
-#include <linux/init.h>
-#include <linux/timex.h>
-#include <linux/profile.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
+#include <linux/cpu.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
#include <asm/irq.h>
#include <asm/arcregs.h>
-#include <asm/clk.h>
-#include <asm/mach_desc.h>
#include <asm/mcip.h>
@@ -60,16 +55,35 @@
#define ARC_TIMER_MAX 0xFFFFFFFF
-/********** Clock Source Device *********/
-
-#ifdef CONFIG_ARC_HAS_GFRC
+static unsigned long arc_timer_freq;
-static int arc_counter_setup(void)
+static int noinline arc_get_timer_clk(struct device_node *node)
{
- return 1;
+ struct clk *clk;
+ int ret;
+
+ clk = of_clk_get(node, 0);
+ if (IS_ERR(clk)) {
+ pr_err("timer missing clk");
+ return PTR_ERR(clk);
+ }
+
+ ret = clk_prepare_enable(clk);
+ if (ret) {
+ pr_err("Couldn't enable parent clk\n");
+ return ret;
+ }
+
+ arc_timer_freq = clk_get_rate(clk);
+
+ return 0;
}
-static cycle_t arc_counter_read(struct clocksource *cs)
+/********** Clock Source Device *********/
+
+#ifdef CONFIG_ARC_HAS_GFRC
+
+static cycle_t arc_read_gfrc(struct clocksource *cs)
{
unsigned long flags;
union {
@@ -94,15 +108,31 @@ static cycle_t arc_counter_read(struct clocksource *cs)
return stamp.full;
}
-static struct clocksource arc_counter = {
+static struct clocksource arc_counter_gfrc = {
.name = "ARConnect GFRC",
.rating = 400,
- .read = arc_counter_read,
+ .read = arc_read_gfrc,
.mask = CLOCKSOURCE_MASK(64),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
-#else
+static void __init arc_cs_setup_gfrc(struct device_node *node)
+{
+ int exists = cpuinfo_arc700[0].extn.gfrc;
+ int ret;
+
+ if (WARN(!exists, "Global-64-bit-Ctr clocksource not detected"))
+ return;
+
+ ret = arc_get_timer_clk(node);
+ if (ret)
+ return;
+
+ clocksource_register_hz(&arc_counter_gfrc, arc_timer_freq);
+}
+CLOCKSOURCE_OF_DECLARE(arc_gfrc, "snps,archs-timer-gfrc", arc_cs_setup_gfrc);
+
+#endif
#ifdef CONFIG_ARC_HAS_RTC
@@ -110,15 +140,7 @@ static struct clocksource arc_counter = {
#define AUX_RTC_LOW 0x104
#define AUX_RTC_HIGH 0x105
-int arc_counter_setup(void)
-{
- write_aux_reg(AUX_RTC_CTRL, 1);
-
- /* Not usable in SMP */
- return !IS_ENABLED(CONFIG_SMP);
-}
-
-static cycle_t arc_counter_read(struct clocksource *cs)
+static cycle_t arc_read_rtc(struct clocksource *cs)
{
unsigned long status;
union {
@@ -142,47 +164,78 @@ static cycle_t arc_counter_read(struct clocksource *cs)
return stamp.full;
}
-static struct clocksource arc_counter = {
+static struct clocksource arc_counter_rtc = {
.name = "ARCv2 RTC",
.rating = 350,
- .read = arc_counter_read,
+ .read = arc_read_rtc,
.mask = CLOCKSOURCE_MASK(64),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
-#else /* !CONFIG_ARC_HAS_RTC */
-
-/*
- * set 32bit TIMER1 to keep counting monotonically and wraparound
- */
-int arc_counter_setup(void)
+static void __init arc_cs_setup_rtc(struct device_node *node)
{
- write_aux_reg(ARC_REG_TIMER1_LIMIT, ARC_TIMER_MAX);
- write_aux_reg(ARC_REG_TIMER1_CNT, 0);
- write_aux_reg(ARC_REG_TIMER1_CTRL, TIMER_CTRL_NH);
+ int exists = cpuinfo_arc700[smp_processor_id()].extn.rtc;
+ int ret;
+
+ if (WARN(!exists, "Local-64-bit-Ctr clocksource not detected"))
+ return;
+
+ /* Local to CPU hence not usable in SMP */
+ if (WARN(IS_ENABLED(CONFIG_SMP), "Local-64-bit-Ctr not usable in SMP"))
+ return;
+
+ ret = arc_get_timer_clk(node);
+ if (ret)
+ return;
+
+ write_aux_reg(AUX_RTC_CTRL, 1);
- /* Not usable in SMP */
- return !IS_ENABLED(CONFIG_SMP);
+ clocksource_register_hz(&arc_counter_rtc, arc_timer_freq);
}
+CLOCKSOURCE_OF_DECLARE(arc_rtc, "snps,archs-timer-rtc", arc_cs_setup_rtc);
-static cycle_t arc_counter_read(struct clocksource *cs)
+#endif
+
+/*
+ * 32bit TIMER1 to keep counting monotonically and wraparound
+ */
+
+static cycle_t arc_read_timer1(struct clocksource *cs)
{
return (cycle_t) read_aux_reg(ARC_REG_TIMER1_CNT);
}
-static struct clocksource arc_counter = {
+static struct clocksource arc_counter_timer1 = {
.name = "ARC Timer1",
.rating = 300,
- .read = arc_counter_read,
+ .read = arc_read_timer1,
.mask = CLOCKSOURCE_MASK(32),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
-#endif
-#endif
+static void __init arc_cs_setup_timer1(struct device_node *node)
+{
+ int ret;
+
+ /* Local to CPU hence not usable in SMP */
+ if (IS_ENABLED(CONFIG_SMP))
+ return;
+
+ ret = arc_get_timer_clk(node);
+ if (ret)
+ return;
+
+ write_aux_reg(ARC_REG_TIMER1_LIMIT, ARC_TIMER_MAX);
+ write_aux_reg(ARC_REG_TIMER1_CNT, 0);
+ write_aux_reg(ARC_REG_TIMER1_CTRL, TIMER_CTRL_NH);
+
+ clocksource_register_hz(&arc_counter_timer1, arc_timer_freq);
+}
/********** Clock Event Device *********/
+static int arc_timer_irq;
+
/*
* Arm the timer to interrupt after @cycles
* The distinction for oneshot/periodic is done in arc_event_timer_ack() below
@@ -209,7 +262,7 @@ static int arc_clkevent_set_periodic(struct clock_event_device *dev)
* At X Hz, 1 sec = 1000ms -> X cycles;
* 10ms -> X / 100 cycles
*/
- arc_timer_event_setup(arc_get_core_freq() / HZ);
+ arc_timer_event_setup(arc_timer_freq / HZ);
return 0;
}
@@ -218,7 +271,6 @@ static DEFINE_PER_CPU(struct clock_event_device, arc_clockevent_device) = {
.features = CLOCK_EVT_FEAT_ONESHOT |
CLOCK_EVT_FEAT_PERIODIC,
.rating = 300,
- .irq = TIMER0_IRQ, /* hardwired, no need for resources */
.set_next_event = arc_clkevent_set_next_event,
.set_state_periodic = arc_clkevent_set_periodic,
};
@@ -244,45 +296,81 @@ static irqreturn_t timer_irq_handler(int irq, void *dev_id)
return IRQ_HANDLED;
}
+static int arc_timer_cpu_notify(struct notifier_block *self,
+ unsigned long action, void *hcpu)
+{
+ struct clock_event_device *evt = this_cpu_ptr(&arc_clockevent_device);
+
+ evt->cpumask = cpumask_of(smp_processor_id());
+
+ switch (action & ~CPU_TASKS_FROZEN) {
+ case CPU_STARTING:
+ clockevents_config_and_register(evt, arc_timer_freq,
+ 0, ULONG_MAX);
+ enable_percpu_irq(arc_timer_irq, 0);
+ break;
+ case CPU_DYING:
+ disable_percpu_irq(arc_timer_irq);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block arc_timer_cpu_nb = {
+ .notifier_call = arc_timer_cpu_notify,
+};
+
/*
- * Setup the local event timer for @cpu
+ * clockevent setup for boot CPU
*/
-void arc_local_timer_setup()
+static void __init arc_clockevent_setup(struct device_node *node)
{
struct clock_event_device *evt = this_cpu_ptr(&arc_clockevent_device);
- int cpu = smp_processor_id();
+ int ret;
+
+ register_cpu_notifier(&arc_timer_cpu_nb);
- evt->cpumask = cpumask_of(cpu);
- clockevents_config_and_register(evt, arc_get_core_freq(),
+ arc_timer_irq = irq_of_parse_and_map(node, 0);
+ if (arc_timer_irq <= 0)
+ panic("clockevent: missing irq");
+
+ ret = arc_get_timer_clk(node);
+ if (ret)
+ panic("clockevent: missing clk");
+
+ evt->irq = arc_timer_irq;
+ evt->cpumask = cpumask_of(smp_processor_id());
+ clockevents_config_and_register(evt, arc_timer_freq,
0, ARC_TIMER_MAX);
- /* setup the per-cpu timer IRQ handler - for all cpus */
- arc_request_percpu_irq(TIMER0_IRQ, cpu, timer_irq_handler,
- "Timer0 (per-cpu-tick)", evt);
+ /* Needs apriori irq_set_percpu_devid() done in intc map function */
+ ret = request_percpu_irq(arc_timer_irq, timer_irq_handler,
+ "Timer0 (per-cpu-tick)", evt);
+ if (ret)
+ panic("clockevent: unable to request irq\n");
+
+ enable_percpu_irq(arc_timer_irq, 0);
}
+static void __init arc_of_timer_init(struct device_node *np)
+{
+ static int init_count = 0;
+
+ if (!init_count) {
+ init_count = 1;
+ arc_clockevent_setup(np);
+ } else {
+ arc_cs_setup_timer1(np);
+ }
+}
+CLOCKSOURCE_OF_DECLARE(arc_clkevt, "snps,arc-timer", arc_of_timer_init);
+
/*
* Called from start_kernel() - boot CPU only
- *
- * -Sets up h/w timers as applicable on boot cpu
- * -Also sets up any global state needed for timer subsystem:
- * - for "counting" timer, registers a clocksource, usable across CPUs
- * (provided that underlying counter h/w is synchronized across cores)
- * - for "event" timer, sets up TIMER0 IRQ (as that is platform agnostic)
*/
void __init time_init(void)
{
- /*
- * sets up the timekeeping free-flowing counter which also returns
- * whether the counter is usable as clocksource
- */
- if (arc_counter_setup())
- /*
- * CLK upto 4.29 GHz can be safely represented in 32 bits
- * because Max 32 bit number is 4,294,967,295
- */
- clocksource_register_hz(&arc_counter, arc_get_core_freq());
-
- /* sets up the periodic event timer */
- arc_local_timer_setup();
+ of_clk_init(NULL);
+ clocksource_probe();
}