Add suspend/resume PM sleep ops. When going to low power, enforce the
counter isn't active.
Signed-off-by: Fabrice Gasnier <[email protected]>
---
drivers/counter/stm32-timer-cnt.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
index 3eafcce..3b84503 100644
--- a/drivers/counter/stm32-timer-cnt.c
+++ b/drivers/counter/stm32-timer-cnt.c
@@ -12,6 +12,7 @@
#include <linux/iio/types.h>
#include <linux/mfd/stm32-timers.h>
#include <linux/module.h>
+#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#define TIM_CCMR_CCXS (BIT(8) | BIT(0))
@@ -358,10 +359,33 @@ static int stm32_timer_cnt_probe(struct platform_device *pdev)
priv->counter.num_signals = ARRAY_SIZE(stm32_signals);
priv->counter.priv = priv;
+ platform_set_drvdata(pdev, priv);
+
/* Register Counter device */
return devm_counter_register(dev, &priv->counter);
}
+static int __maybe_unused stm32_timer_cnt_suspend(struct device *dev)
+{
+ struct stm32_timer_cnt *priv = dev_get_drvdata(dev);
+ u32 cr1;
+
+ /* Check for active counter */
+ regmap_read(priv->regmap, TIM_CR1, &cr1);
+ if (cr1 & TIM_CR1_CEN)
+ return -EBUSY;
+
+ return pinctrl_pm_select_sleep_state(dev);
+}
+
+static int __maybe_unused stm32_timer_cnt_resume(struct device *dev)
+{
+ return pinctrl_pm_select_default_state(dev);
+}
+
+static SIMPLE_DEV_PM_OPS(stm32_timer_cnt_pm_ops, stm32_timer_cnt_suspend,
+ stm32_timer_cnt_resume);
+
static const struct of_device_id stm32_timer_cnt_of_match[] = {
{ .compatible = "st,stm32-timer-counter", },
{},
@@ -373,6 +397,7 @@ static struct platform_driver stm32_timer_cnt_driver = {
.driver = {
.name = "stm32-timer-counter",
.of_match_table = stm32_timer_cnt_of_match,
+ .pm = &stm32_timer_cnt_pm_ops,
},
};
module_platform_driver(stm32_timer_cnt_driver);
--
2.7.4
On Wed, Feb 05, 2020 at 11:47:58AM +0100, Fabrice Gasnier wrote:
> Add suspend/resume PM sleep ops. When going to low power, enforce the
> counter isn't active.
>
> Signed-off-by: Fabrice Gasnier <[email protected]>
These changes are purely for the PM ops and don't involve the Counter
API, so I don't see any see any issues with this patch from my end.
Acked-by: William Breathitt Gray <[email protected]>
> ---
> drivers/counter/stm32-timer-cnt.c | 25 +++++++++++++++++++++++++
> 1 file changed, 25 insertions(+)
>
> diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
> index 3eafcce..3b84503 100644
> --- a/drivers/counter/stm32-timer-cnt.c
> +++ b/drivers/counter/stm32-timer-cnt.c
> @@ -12,6 +12,7 @@
> #include <linux/iio/types.h>
> #include <linux/mfd/stm32-timers.h>
> #include <linux/module.h>
> +#include <linux/pinctrl/consumer.h>
> #include <linux/platform_device.h>
>
> #define TIM_CCMR_CCXS (BIT(8) | BIT(0))
> @@ -358,10 +359,33 @@ static int stm32_timer_cnt_probe(struct platform_device *pdev)
> priv->counter.num_signals = ARRAY_SIZE(stm32_signals);
> priv->counter.priv = priv;
>
> + platform_set_drvdata(pdev, priv);
> +
> /* Register Counter device */
> return devm_counter_register(dev, &priv->counter);
> }
>
> +static int __maybe_unused stm32_timer_cnt_suspend(struct device *dev)
> +{
> + struct stm32_timer_cnt *priv = dev_get_drvdata(dev);
> + u32 cr1;
> +
> + /* Check for active counter */
> + regmap_read(priv->regmap, TIM_CR1, &cr1);
> + if (cr1 & TIM_CR1_CEN)
> + return -EBUSY;
> +
> + return pinctrl_pm_select_sleep_state(dev);
> +}
> +
> +static int __maybe_unused stm32_timer_cnt_resume(struct device *dev)
> +{
> + return pinctrl_pm_select_default_state(dev);
> +}
> +
> +static SIMPLE_DEV_PM_OPS(stm32_timer_cnt_pm_ops, stm32_timer_cnt_suspend,
> + stm32_timer_cnt_resume);
> +
> static const struct of_device_id stm32_timer_cnt_of_match[] = {
> { .compatible = "st,stm32-timer-counter", },
> {},
> @@ -373,6 +397,7 @@ static struct platform_driver stm32_timer_cnt_driver = {
> .driver = {
> .name = "stm32-timer-counter",
> .of_match_table = stm32_timer_cnt_of_match,
> + .pm = &stm32_timer_cnt_pm_ops,
> },
> };
> module_platform_driver(stm32_timer_cnt_driver);
> --
> 2.7.4
>
On Wed, 5 Feb 2020 11:47:58 +0100
Fabrice Gasnier <[email protected]> wrote:
> Add suspend/resume PM sleep ops. When going to low power, enforce the
> counter isn't active.
>
> Signed-off-by: Fabrice Gasnier <[email protected]>
> ---
> drivers/counter/stm32-timer-cnt.c | 25 +++++++++++++++++++++++++
> 1 file changed, 25 insertions(+)
>
> diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
> index 3eafcce..3b84503 100644
> --- a/drivers/counter/stm32-timer-cnt.c
> +++ b/drivers/counter/stm32-timer-cnt.c
> @@ -12,6 +12,7 @@
> #include <linux/iio/types.h>
> #include <linux/mfd/stm32-timers.h>
> #include <linux/module.h>
> +#include <linux/pinctrl/consumer.h>
> #include <linux/platform_device.h>
>
> #define TIM_CCMR_CCXS (BIT(8) | BIT(0))
> @@ -358,10 +359,33 @@ static int stm32_timer_cnt_probe(struct platform_device *pdev)
> priv->counter.num_signals = ARRAY_SIZE(stm32_signals);
> priv->counter.priv = priv;
>
> + platform_set_drvdata(pdev, priv);
> +
> /* Register Counter device */
> return devm_counter_register(dev, &priv->counter);
> }
>
> +static int __maybe_unused stm32_timer_cnt_suspend(struct device *dev)
> +{
> + struct stm32_timer_cnt *priv = dev_get_drvdata(dev);
> + u32 cr1;
> +
> + /* Check for active counter */
> + regmap_read(priv->regmap, TIM_CR1, &cr1);
> + if (cr1 & TIM_CR1_CEN)
> + return -EBUSY;
Runtime suspend is allowed to refuse to happen (and that is
explicitly documented)
Is that allowed for normal suspend? I didn't think it was.
This will stop a suspend, but it's doing it by signalling a failure.
I'm not sure for example that the system will resume everything that
was suspended before this call.
Normally you are in the tough luck category if a system decides
to suspend underneath you. There are ways to prevent it
from userspace (wakelocks etc).
> +
> + return pinctrl_pm_select_sleep_state(dev);
> +}
> +
> +static int __maybe_unused stm32_timer_cnt_resume(struct device *dev)
> +{
> + return pinctrl_pm_select_default_state(dev);
> +}
> +
> +static SIMPLE_DEV_PM_OPS(stm32_timer_cnt_pm_ops, stm32_timer_cnt_suspend,
> + stm32_timer_cnt_resume);
> +
> static const struct of_device_id stm32_timer_cnt_of_match[] = {
> { .compatible = "st,stm32-timer-counter", },
> {},
> @@ -373,6 +397,7 @@ static struct platform_driver stm32_timer_cnt_driver = {
> .driver = {
> .name = "stm32-timer-counter",
> .of_match_table = stm32_timer_cnt_of_match,
> + .pm = &stm32_timer_cnt_pm_ops,
> },
> };
> module_platform_driver(stm32_timer_cnt_driver);
On 2/8/20 4:35 PM, Jonathan Cameron wrote:
> On Wed, 5 Feb 2020 11:47:58 +0100
> Fabrice Gasnier <[email protected]> wrote:
>
>> Add suspend/resume PM sleep ops. When going to low power, enforce the
>> counter isn't active.
>>
>> Signed-off-by: Fabrice Gasnier <[email protected]>
>> ---
>> drivers/counter/stm32-timer-cnt.c | 25 +++++++++++++++++++++++++
>> 1 file changed, 25 insertions(+)
>>
>> diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
>> index 3eafcce..3b84503 100644
>> --- a/drivers/counter/stm32-timer-cnt.c
>> +++ b/drivers/counter/stm32-timer-cnt.c
>> @@ -12,6 +12,7 @@
>> #include <linux/iio/types.h>
>> #include <linux/mfd/stm32-timers.h>
>> #include <linux/module.h>
>> +#include <linux/pinctrl/consumer.h>
>> #include <linux/platform_device.h>
>>
>> #define TIM_CCMR_CCXS (BIT(8) | BIT(0))
>> @@ -358,10 +359,33 @@ static int stm32_timer_cnt_probe(struct platform_device *pdev)
>> priv->counter.num_signals = ARRAY_SIZE(stm32_signals);
>> priv->counter.priv = priv;
>>
>> + platform_set_drvdata(pdev, priv);
>> +
>> /* Register Counter device */
>> return devm_counter_register(dev, &priv->counter);
>> }
>>
>> +static int __maybe_unused stm32_timer_cnt_suspend(struct device *dev)
>> +{
>> + struct stm32_timer_cnt *priv = dev_get_drvdata(dev);
>> + u32 cr1;
>> +
>> + /* Check for active counter */
>> + regmap_read(priv->regmap, TIM_CR1, &cr1);
>> + if (cr1 & TIM_CR1_CEN)
>> + return -EBUSY;
>
> Runtime suspend is allowed to refuse to happen (and that is
> explicitly documented)
> Is that allowed for normal suspend? I didn't think it was.
> This will stop a suspend, but it's doing it by signalling a failure.
Hi Jonathan,
I'll rework this patch, to avoid stopping the suspend. Another approach
is to properly save/backup the registers here, and to disable the
counter in low power mode.
I'll update this in V2.
Thanks for reviewing,
Fabrice
> I'm not sure for example that the system will resume everything that
> was suspended before this call.
>
> Normally you are in the tough luck category if a system decides
> to suspend underneath you. There are ways to prevent it
> from userspace (wakelocks etc).
>
>> +
>> + return pinctrl_pm_select_sleep_state(dev);
>> +}
>> +
>> +static int __maybe_unused stm32_timer_cnt_resume(struct device *dev)
>> +{
>> + return pinctrl_pm_select_default_state(dev);
>> +}
>> +
>> +static SIMPLE_DEV_PM_OPS(stm32_timer_cnt_pm_ops, stm32_timer_cnt_suspend,
>> + stm32_timer_cnt_resume);
>> +
>> static const struct of_device_id stm32_timer_cnt_of_match[] = {
>> { .compatible = "st,stm32-timer-counter", },
>> {},
>> @@ -373,6 +397,7 @@ static struct platform_driver stm32_timer_cnt_driver = {
>> .driver = {
>> .name = "stm32-timer-counter",
>> .of_match_table = stm32_timer_cnt_of_match,
>> + .pm = &stm32_timer_cnt_pm_ops,
>> },
>> };
>> module_platform_driver(stm32_timer_cnt_driver);
>