[PATCHv2 04/16] clocksource: time-armada-370-xp: add suspend/resume support

From: Thomas Petazzoni
Date: Fri Nov 14 2014 - 10:22:36 EST


This commit adds a set of suspend/resume syscore_ops to respectively
save and restore a number of timer registers, in order to make sure
the clockevent and clocksource devices continue to work properly
across a suspend/resume cycle.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/clocksource/time-armada-370-xp.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)

diff --git a/drivers/clocksource/time-armada-370-xp.c b/drivers/clocksource/time-armada-370-xp.c
index 0451e62..ff37d3a 100644
--- a/drivers/clocksource/time-armada-370-xp.c
+++ b/drivers/clocksource/time-armada-370-xp.c
@@ -43,6 +43,7 @@
#include <linux/module.h>
#include <linux/sched_clock.h>
#include <linux/percpu.h>
+#include <linux/syscore_ops.h>

/*
* Timer block registers.
@@ -223,6 +224,28 @@ static struct notifier_block armada_370_xp_timer_cpu_nb = {
.notifier_call = armada_370_xp_timer_cpu_notify,
};

+static u32 timer0_ctrl_reg, timer0_local_ctrl_reg;
+
+static int armada_370_xp_timer_suspend(void)
+{
+ timer0_ctrl_reg = readl(timer_base + TIMER_CTRL_OFF);
+ timer0_local_ctrl_reg = readl(local_base + TIMER_CTRL_OFF);
+ return 0;
+}
+
+static void armada_370_xp_timer_resume(void)
+{
+ writel(0xffffffff, timer_base + TIMER0_VAL_OFF);
+ writel(0xffffffff, timer_base + TIMER0_RELOAD_OFF);
+ writel(timer0_ctrl_reg, timer_base + TIMER_CTRL_OFF);
+ writel(timer0_local_ctrl_reg, local_base + TIMER_CTRL_OFF);
+}
+
+struct syscore_ops armada_370_xp_timer_syscore_ops = {
+ .suspend = armada_370_xp_timer_suspend,
+ .resume = armada_370_xp_timer_resume,
+};
+
static void __init armada_370_xp_timer_common_init(struct device_node *np)
{
u32 clr = 0, set = 0;
@@ -285,6 +308,8 @@ static void __init armada_370_xp_timer_common_init(struct device_node *np)
/* Immediately configure the timer on the boot CPU */
if (!res)
armada_370_xp_timer_setup(this_cpu_ptr(armada_370_xp_evt));
+
+ register_syscore_ops(&armada_370_xp_timer_syscore_ops);
}

static void __init armada_xp_timer_init(struct device_node *np)
--
2.1.0

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