2014-10-24 11:59:52

by Thomas Petazzoni

Subject: [PATCH 05/17] clocksource: time-armada-370-xp: add suspend/resume support

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
accross a suspend/resume cycle.

Signed-off-by: Thomas Petazzoni <[email protected]>
Cc: Daniel Lezcano <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
---
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..1a32dcb 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 timer_ctrl_reg, timer_local_ctrl_reg;
+
+static int armada_370_xp_timer_suspend(void)
+{
+ timer_ctrl_reg = readl(timer_base + TIMER_CTRL_OFF);
+ timer_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(timer_ctrl_reg, timer_base + TIMER_CTRL_OFF);
+ writel(timer_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)
--
2.0.0

2014-11-03 17:45:19

by Gregory CLEMENT

Subject: Re: [PATCH 05/17] clocksource: time-armada-370-xp: add suspend/resume support

Hi Thomas,

On 24/10/2014 13:59, Thomas Petazzoni wrote:
> 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
> accross a suspend/resume cycle.
across

>
> Signed-off-by: Thomas Petazzoni <[email protected]>
> Cc: Daniel Lezcano <[email protected]>
> Cc: Thomas Gleixner <[email protected]>
> Cc: [email protected]
> ---
> 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..1a32dcb 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 timer_ctrl_reg, timer_local_ctrl_reg;

We don't need to restore any other timer than the timer 0, but it
would worth mentioning that we save and restore only this one
by naming the variable timer0_ctrl_reg and timer0_local_ctrl_reg

Besides this and the typo:

Acked-by: Gregory CLEMENT <[email protected]>


Thanks,

Gregory


--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com