[PATCH 5/9] ARC: clockevent: DT based probe
From: Vineet Gupta
Date: Tue Feb 02 2016 - 06:00:12 EST
- timer frequency is derived from DT (no longer rely on top level
DT "clock-frequency" probed early and exported by asm/clk.h)
- TIMER0_IRQ need not be exported across arch code, confided to intc as
it is property of same
Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
---
arch/arc/include/asm/irq.h | 4 ---
arch/arc/kernel/intc-compact.c | 2 ++
arch/arc/kernel/time.c | 67 ++++++++++++++++++++++++++----------------
3 files changed, 44 insertions(+), 29 deletions(-)
diff --git a/arch/arc/include/asm/irq.h b/arch/arc/include/asm/irq.h
index 0c86f0787bcd..44b6ea85e8fb 100644
--- a/arch/arc/include/asm/irq.h
+++ b/arch/arc/include/asm/irq.h
@@ -14,12 +14,8 @@
/* Platform Independent IRQs */
#ifdef CONFIG_ISA_ARCOMPACT
-#define TIMER0_IRQ 3
-#define TIMER1_IRQ 4
#define IPI_IRQ (NR_CPU_IRQS-1) /* dummy to enable SMP build for up hardware */
#else
-#define TIMER0_IRQ 16
-#define TIMER1_IRQ 17
#define IPI_IRQ 19
#endif
diff --git a/arch/arc/kernel/intc-compact.c b/arch/arc/kernel/intc-compact.c
index 06bcedf19b62..5d390958d233 100644
--- a/arch/arc/kernel/intc-compact.c
+++ b/arch/arc/kernel/intc-compact.c
@@ -14,6 +14,8 @@
#include <linux/irqchip.h>
#include <asm/irq.h>
+#define TIMER0_IRQ 3 /* Fixed by ISA */
+
/*
* Early Hardware specific Interrupt setup
* -Platform independent, needed for each CPU (not foldable into init_IRQ)
diff --git a/arch/arc/kernel/time.c b/arch/arc/kernel/time.c
index 1f5a6fe03bcc..43ef22853473 100644
--- a/arch/arc/kernel/time.c
+++ b/arch/arc/kernel/time.c
@@ -29,22 +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-provider.h>
+#include <linux/clk.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>
@@ -61,6 +55,24 @@
#define ARC_TIMER_MAX 0xFFFFFFFF
+static unsigned long arc_timer_freq;
+
+static void noinline arc_get_timer_clk(struct device_node *node)
+{
+ struct clk *clk;
+ int ret;
+
+ clk = of_clk_get(node, 0);
+ if (IS_ERR(clk))
+ panic("Can't get timer clock");
+
+ ret = clk_prepare_enable(clk);
+ if (ret)
+ pr_err("Couldn't enable parent clock\n");
+
+ arc_timer_freq = clk_get_rate(clk);
+}
+
/********** Clock Source Device *********/
#ifdef CONFIG_ARC_HAS_GFRC
@@ -184,7 +196,7 @@ static struct clocksource arc_counter = {
/********** Clock Event Device *********/
-static int arc_timer_irq = TIMER0_IRQ;
+static int arc_timer_irq;
/*
* Arm the timer to interrupt after @cycles
@@ -212,7 +224,7 @@ 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;
}
@@ -221,7 +233,6 @@ 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,
};
@@ -256,7 +267,7 @@ static int arc_timer_cpu_notify(struct notifier_block *self,
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_STARTING:
- clockevents_config_and_register(evt, arc_get_core_freq(),
+ clockevents_config_and_register(evt, arc_timer_freq,
0, ULONG_MAX);
enable_percpu_irq(arc_timer_irq, 0);
break;
@@ -268,32 +279,41 @@ static int arc_timer_cpu_notify(struct notifier_block *self,
return NOTIFY_OK;
}
-static struct notifier_block nps_timer_cpu_nb = {
+static struct notifier_block arc_timer_cpu_nb = {
.notifier_call = arc_timer_cpu_notify,
};
/*
* clockevent setup for boot CPU
*/
-static void __init arc_clockevent_setup()
+static void __init arc_clockevent_setup(struct device_node *node)
{
struct clock_event_device *evt = this_cpu_ptr(&arc_clockevent_device);
+ int ret;
register_cpu_notifier(&arc_timer_cpu_nb);
+ arc_timer_irq = irq_of_parse_and_map(node, 0);
+ if (arc_timer_irq <= 0)
+ panic("Can't parse IRQ");
+
+ arc_get_timer_clk(node);
+
+ evt->irq = arc_timer_irq;
evt->cpumask = cpumask_of(smp_processor_id());
- clockevents_config_and_register(evt, arc_get_core_freq(),
+ clockevents_config_and_register(evt, arc_timer_freq,
0, ARC_TIMER_MAX);
/* setup the per-cpu timer IRQ handler - for all cpus */
- request_percpu_irq(arc_timer_irq, timer_irq_handler,
- "Timer0 (per-cpu-tick)", evt);
+ ret = request_percpu_irq(arc_timer_irq, timer_irq_handler,
+ "Timer0 (per-cpu-tick)", evt);
+ if (ret)
+ pr_err("Unable to register interrupt\n");
enable_percpu_irq(arc_timer_irq, 0);
- if (ret)
- pr_err("Unable to register interrupt\n");
}
+CLOCKSOURCE_OF_DECLARE(arc_clkevt, "snps,arc-timer0", arc_clockevent_setup);
/*
* Called from start_kernel() - boot CPU only
@@ -302,7 +322,6 @@ static void __init arc_clockevent_setup()
* -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)
{
@@ -318,7 +337,5 @@ void __init time_init(void)
* 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());
-
- arc_clockevent_setup();
+ clocksource_register_hz(&arc_counter, arc_timer_freq);
}
--
2.5.0