[PATCH 4/8] clocksource: arm_arch_timer: Register the persistent clock

From: Baolin Wang
Date: Wed Jun 13 2018 - 07:33:39 EST


Register the persistent clock to compensate the suspend time for OS time,
if the ARM counter clocksource will not be stopped in suspend state.

Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
---
drivers/clocksource/Kconfig | 1 +
drivers/clocksource/arm_arch_timer.c | 10 ++++++++++
2 files changed, 11 insertions(+)

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 7f11c6c..5e51fcf 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -308,6 +308,7 @@ config ARC_TIMERS_64BIT

config ARM_ARCH_TIMER
bool
+ select PERSISTENT_CLOCK
select TIMER_OF if OF
select TIMER_ACPI if ACPI

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 57cb2f0..671be63 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -32,6 +32,7 @@
#include <asm/virt.h>

#include <clocksource/arm_arch_timer.h>
+#include <linux/persistent_clock.h>

#undef pr_fmt
#define pr_fmt(fmt) "arch_timer: " fmt
@@ -950,6 +951,15 @@ static void __init arch_counter_register(unsigned type)

/* 56 bits minimum, so we assume worst case rollover */
sched_clock_register(arch_timer_read_counter, 56, arch_timer_rate);
+
+ /*
+ * Register the persistent clock if the clocksource will not be stopped
+ * in suspend state.
+ */
+ if (!arch_counter_suspend_stop)
+ persistent_clock_init_and_register(arch_timer_read_counter,
+ CLOCKSOURCE_MASK(56),
+ arch_timer_rate, 0);
}

static void arch_timer_stop(struct clock_event_device *clk)
--
1.7.9.5