[PATCH v5 09/20] ARC: IRQ: use device tree to get timer device configuration

From: Noam Camus
Date: Sun Dec 27 2015 - 08:43:27 EST


From: Noam Camus <noamc@xxxxxxxxxx>

We've designated:
TIMER0 for events (clockevents)
TIMER1 for free running (clocksource)

Till now timer configuration was done on arch/arc/kernel/time.c
with constant values.

This commit add device tree support so we can do this work
at dedicated clocksource driver which parse the DT blob.

Such driver will get clocksource rate as well as interrupt line
from DT and use them for setting clocksourcse and clockevents.

Note that lately called of_clk_init() is moved before we call
clocksource_probe() since at that time device from DT
need a "provider" (clocks) which will be available only after
we call to of_clk_init().

Signed-off-by: Noam Camus <noamc@xxxxxxxxxx>
Acked-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
---
arch/arc/kernel/setup.c | 1 -
arch/arc/kernel/smp.c | 2 ++
arch/arc/kernel/time.c | 8 ++++++++
3 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index e1b8744..4681e9c 100644
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -433,7 +433,6 @@ void __init setup_arch(char **cmdline_p)

static int __init customize_machine(void)
{
- of_clk_init(NULL);
/*
* Traverses flattened DeviceTree - registering platform devices
* (if any) complete with their resources
diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c
index 2cfe135..ec6a5c1 100644
--- a/arch/arc/kernel/smp.c
+++ b/arch/arc/kernel/smp.c
@@ -138,7 +138,9 @@ void start_kernel_secondary(void)

pr_info("## CPU%u LIVE ##: Executing Code...\n", cpu);

+#ifndef CONFIG_CLKSRC_OF
arc_local_timer_setup();
+#endif

local_irq_enable();
preempt_disable();
diff --git a/arch/arc/kernel/time.c b/arch/arc/kernel/time.c
index dfad287..be6dd9e 100644
--- a/arch/arc/kernel/time.c
+++ b/arch/arc/kernel/time.c
@@ -38,6 +38,7 @@
#include <linux/init.h>
#include <linux/timex.h>
#include <linux/profile.h>
+#include <linux/clk-provider.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <asm/irq.h>
@@ -283,6 +284,13 @@ void __init time_init(void)
*/
clocksource_register_hz(&arc_counter, arc_get_core_freq());

+#ifdef CONFIG_COMMON_CLK
+ of_clk_init(NULL);
+#endif
+#ifdef CONFIG_CLKSRC_OF
+ clocksource_probe();
+#else
/* sets up the periodic event timer */
arc_local_timer_setup();
+#endif
}
--
1.7.1

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