Add suspend/resume PM sleep ops. When going to low power, enforce the
counter isn't active. Gracefully restore its state upon resume in case
it's been left enabled prior to suspend.
Acked-by: William Breathitt Gray <[email protected]>
Signed-off-by: Fabrice Gasnier <[email protected]>
---
Changes in v2:
- Don't refuse to suspend in case the counter has been left enabled.
Gracefully disable it and restore its state upon resume.
---
drivers/counter/stm32-timer-cnt.c | 63 +++++++++++++++++++++++++++++++++++++++
1 file changed, 63 insertions(+)
diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
index 3eafcce..50496f4 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))
@@ -20,11 +21,20 @@
#define TIM_CCER_MASK (TIM_CCER_CC1P | TIM_CCER_CC1NP | \
TIM_CCER_CC2P | TIM_CCER_CC2NP)
+struct stm32_timer_regs {
+ u32 cr1;
+ u32 cnt;
+ u32 smcr;
+ u32 arr;
+};
+
struct stm32_timer_cnt {
struct counter_device counter;
struct regmap *regmap;
struct clk *clk;
u32 ceiling;
+ bool enabled;
+ struct stm32_timer_regs bak;
};
/**
@@ -224,6 +234,9 @@ static ssize_t stm32_count_enable_write(struct counter_device *counter,
clk_disable(priv->clk);
}
+ /* Keep enabled state to properly handle low power states */
+ priv->enabled = enable;
+
return len;
}
@@ -358,10 +371,59 @@ 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);
+
+ /* Only take care of enabled counter: don't disturb other MFD child */
+ if (priv->enabled) {
+ /* Backup registers that may get lost in low power mode */
+ regmap_read(priv->regmap, TIM_SMCR, &priv->bak.smcr);
+ regmap_read(priv->regmap, TIM_ARR, &priv->bak.arr);
+ regmap_read(priv->regmap, TIM_CNT, &priv->bak.cnt);
+ regmap_read(priv->regmap, TIM_CR1, &priv->bak.cr1);
+
+ /* Disable the counter */
+ regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
+ clk_disable(priv->clk);
+ }
+
+ return pinctrl_pm_select_sleep_state(dev);
+}
+
+static int __maybe_unused stm32_timer_cnt_resume(struct device *dev)
+{
+ struct stm32_timer_cnt *priv = dev_get_drvdata(dev);
+ int ret;
+
+ ret = pinctrl_pm_select_default_state(dev);
+ if (ret)
+ return ret;
+
+ if (priv->enabled) {
+ clk_enable(priv->clk);
+
+ /* Restore registers that may have been lost */
+ regmap_write(priv->regmap, TIM_SMCR, priv->bak.smcr);
+ regmap_write(priv->regmap, TIM_ARR, priv->bak.arr);
+ regmap_write(priv->regmap, TIM_CNT, priv->bak.cnt);
+
+ /* Also re-enables the counter */
+ regmap_write(priv->regmap, TIM_CR1, priv->bak.cr1);
+ }
+
+ return 0;
+}
+
+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 +435,7 @@ 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 Mon, Feb 10, 2020 at 06:19:58PM +0100, Fabrice Gasnier wrote:
> Add suspend/resume PM sleep ops. When going to low power, enforce the
> counter isn't active. Gracefully restore its state upon resume in case
> it's been left enabled prior to suspend.
>
> Acked-by: William Breathitt Gray <[email protected]>
> Signed-off-by: Fabrice Gasnier <[email protected]>
> ---
> Changes in v2:
> - Don't refuse to suspend in case the counter has been left enabled.
> Gracefully disable it and restore its state upon resume.
> ---
> drivers/counter/stm32-timer-cnt.c | 63 +++++++++++++++++++++++++++++++++++++++
> 1 file changed, 63 insertions(+)
>
> diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
> index 3eafcce..50496f4 100644
> --- a/drivers/counter/stm32-timer-cnt.c
> +++ b/drivers/counter/stm32-timer-cnt.c
> @@ -12,6 +12,7 @@
> #include <linux/iio/types.h>
Unrelated to your patch but it caught my eye: are iio headers necessary
for this file? I suspect they are not needed since this driver does not
make use of the IIO interface.
William Breathitt Gray
> #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))
> @@ -20,11 +21,20 @@
> #define TIM_CCER_MASK (TIM_CCER_CC1P | TIM_CCER_CC1NP | \
> TIM_CCER_CC2P | TIM_CCER_CC2NP)
>
> +struct stm32_timer_regs {
> + u32 cr1;
> + u32 cnt;
> + u32 smcr;
> + u32 arr;
> +};
> +
> struct stm32_timer_cnt {
> struct counter_device counter;
> struct regmap *regmap;
> struct clk *clk;
> u32 ceiling;
> + bool enabled;
> + struct stm32_timer_regs bak;
> };
>
> /**
> @@ -224,6 +234,9 @@ static ssize_t stm32_count_enable_write(struct counter_device *counter,
> clk_disable(priv->clk);
> }
>
> + /* Keep enabled state to properly handle low power states */
> + priv->enabled = enable;
> +
> return len;
> }
>
> @@ -358,10 +371,59 @@ 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);
> +
> + /* Only take care of enabled counter: don't disturb other MFD child */
> + if (priv->enabled) {
> + /* Backup registers that may get lost in low power mode */
> + regmap_read(priv->regmap, TIM_SMCR, &priv->bak.smcr);
> + regmap_read(priv->regmap, TIM_ARR, &priv->bak.arr);
> + regmap_read(priv->regmap, TIM_CNT, &priv->bak.cnt);
> + regmap_read(priv->regmap, TIM_CR1, &priv->bak.cr1);
> +
> + /* Disable the counter */
> + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
> + clk_disable(priv->clk);
> + }
> +
> + return pinctrl_pm_select_sleep_state(dev);
> +}
> +
> +static int __maybe_unused stm32_timer_cnt_resume(struct device *dev)
> +{
> + struct stm32_timer_cnt *priv = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = pinctrl_pm_select_default_state(dev);
> + if (ret)
> + return ret;
> +
> + if (priv->enabled) {
> + clk_enable(priv->clk);
> +
> + /* Restore registers that may have been lost */
> + regmap_write(priv->regmap, TIM_SMCR, priv->bak.smcr);
> + regmap_write(priv->regmap, TIM_ARR, priv->bak.arr);
> + regmap_write(priv->regmap, TIM_CNT, priv->bak.cnt);
> +
> + /* Also re-enables the counter */
> + regmap_write(priv->regmap, TIM_CR1, priv->bak.cr1);
> + }
> +
> + return 0;
> +}
> +
> +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 +435,7 @@ 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 2/10/20 6:45 PM, William Breathitt Gray wrote:
> On Mon, Feb 10, 2020 at 06:19:58PM +0100, Fabrice Gasnier wrote:
>> Add suspend/resume PM sleep ops. When going to low power, enforce the
>> counter isn't active. Gracefully restore its state upon resume in case
>> it's been left enabled prior to suspend.
>>
>> Acked-by: William Breathitt Gray <[email protected]>
>> Signed-off-by: Fabrice Gasnier <[email protected]>
>> ---
>> Changes in v2:
>> - Don't refuse to suspend in case the counter has been left enabled.
>> Gracefully disable it and restore its state upon resume.
>> ---
>> drivers/counter/stm32-timer-cnt.c | 63 +++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 63 insertions(+)
>>
>> diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
>> index 3eafcce..50496f4 100644
>> --- a/drivers/counter/stm32-timer-cnt.c
>> +++ b/drivers/counter/stm32-timer-cnt.c
>> @@ -12,6 +12,7 @@
>> #include <linux/iio/types.h>
>
> Unrelated to your patch but it caught my eye: are iio headers necessary
> for this file? I suspect they are not needed since this driver does not
> make use of the IIO interface.
Hi William,
Yes, you're right. Thanks for pointing this!
I'll push a patch on top of this one to fix it. BTW, I'm not sure if
this needs to be a marked as a fix, as this seems a quite minor issue?
Best Regards,
Fabrice
>
> William Breathitt Gray
>
>> #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))
>> @@ -20,11 +21,20 @@
>> #define TIM_CCER_MASK (TIM_CCER_CC1P | TIM_CCER_CC1NP | \
>> TIM_CCER_CC2P | TIM_CCER_CC2NP)
>>
>> +struct stm32_timer_regs {
>> + u32 cr1;
>> + u32 cnt;
>> + u32 smcr;
>> + u32 arr;
>> +};
>> +
>> struct stm32_timer_cnt {
>> struct counter_device counter;
>> struct regmap *regmap;
>> struct clk *clk;
>> u32 ceiling;
>> + bool enabled;
>> + struct stm32_timer_regs bak;
>> };
>>
>> /**
>> @@ -224,6 +234,9 @@ static ssize_t stm32_count_enable_write(struct counter_device *counter,
>> clk_disable(priv->clk);
>> }
>>
>> + /* Keep enabled state to properly handle low power states */
>> + priv->enabled = enable;
>> +
>> return len;
>> }
>>
>> @@ -358,10 +371,59 @@ 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);
>> +
>> + /* Only take care of enabled counter: don't disturb other MFD child */
>> + if (priv->enabled) {
>> + /* Backup registers that may get lost in low power mode */
>> + regmap_read(priv->regmap, TIM_SMCR, &priv->bak.smcr);
>> + regmap_read(priv->regmap, TIM_ARR, &priv->bak.arr);
>> + regmap_read(priv->regmap, TIM_CNT, &priv->bak.cnt);
>> + regmap_read(priv->regmap, TIM_CR1, &priv->bak.cr1);
>> +
>> + /* Disable the counter */
>> + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
>> + clk_disable(priv->clk);
>> + }
>> +
>> + return pinctrl_pm_select_sleep_state(dev);
>> +}
>> +
>> +static int __maybe_unused stm32_timer_cnt_resume(struct device *dev)
>> +{
>> + struct stm32_timer_cnt *priv = dev_get_drvdata(dev);
>> + int ret;
>> +
>> + ret = pinctrl_pm_select_default_state(dev);
>> + if (ret)
>> + return ret;
>> +
>> + if (priv->enabled) {
>> + clk_enable(priv->clk);
>> +
>> + /* Restore registers that may have been lost */
>> + regmap_write(priv->regmap, TIM_SMCR, priv->bak.smcr);
>> + regmap_write(priv->regmap, TIM_ARR, priv->bak.arr);
>> + regmap_write(priv->regmap, TIM_CNT, priv->bak.cnt);
>> +
>> + /* Also re-enables the counter */
>> + regmap_write(priv->regmap, TIM_CR1, priv->bak.cr1);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +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 +435,7 @@ 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 Tue, Feb 11, 2020 at 11:54:17AM +0100, Fabrice Gasnier wrote:
> On 2/10/20 6:45 PM, William Breathitt Gray wrote:
> > On Mon, Feb 10, 2020 at 06:19:58PM +0100, Fabrice Gasnier wrote:
> >> Add suspend/resume PM sleep ops. When going to low power, enforce the
> >> counter isn't active. Gracefully restore its state upon resume in case
> >> it's been left enabled prior to suspend.
> >>
> >> Acked-by: William Breathitt Gray <[email protected]>
> >> Signed-off-by: Fabrice Gasnier <[email protected]>
> >> ---
> >> Changes in v2:
> >> - Don't refuse to suspend in case the counter has been left enabled.
> >> Gracefully disable it and restore its state upon resume.
> >> ---
> >> drivers/counter/stm32-timer-cnt.c | 63 +++++++++++++++++++++++++++++++++++++++
> >> 1 file changed, 63 insertions(+)
> >>
> >> diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
> >> index 3eafcce..50496f4 100644
> >> --- a/drivers/counter/stm32-timer-cnt.c
> >> +++ b/drivers/counter/stm32-timer-cnt.c
> >> @@ -12,6 +12,7 @@
> >> #include <linux/iio/types.h>
> >
> > Unrelated to your patch but it caught my eye: are iio headers necessary
> > for this file? I suspect they are not needed since this driver does not
> > make use of the IIO interface.
>
> Hi William,
>
> Yes, you're right. Thanks for pointing this!
> I'll push a patch on top of this one to fix it. BTW, I'm not sure if
> this needs to be a marked as a fix, as this seems a quite minor issue?
>
> Best Regards,
> Fabrice
No need for a Fixes tag in this case since this is not a bug fix, but
rather just a minor clean up of the included headers.
Thanks,
William Breathitt Gray
On Mon, 10 Feb 2020 18:19:58 +0100
Fabrice Gasnier <[email protected]> wrote:
> Add suspend/resume PM sleep ops. When going to low power, enforce the
> counter isn't active. Gracefully restore its state upon resume in case
> it's been left enabled prior to suspend.
>
> Acked-by: William Breathitt Gray <[email protected]>
> Signed-off-by: Fabrice Gasnier <[email protected]>
Looks good to me.
Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with it.
Thanks,
Jonathan
> ---
> Changes in v2:
> - Don't refuse to suspend in case the counter has been left enabled.
> Gracefully disable it and restore its state upon resume.
> ---
> drivers/counter/stm32-timer-cnt.c | 63 +++++++++++++++++++++++++++++++++++++++
> 1 file changed, 63 insertions(+)
>
> diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
> index 3eafcce..50496f4 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))
> @@ -20,11 +21,20 @@
> #define TIM_CCER_MASK (TIM_CCER_CC1P | TIM_CCER_CC1NP | \
> TIM_CCER_CC2P | TIM_CCER_CC2NP)
>
> +struct stm32_timer_regs {
> + u32 cr1;
> + u32 cnt;
> + u32 smcr;
> + u32 arr;
> +};
> +
> struct stm32_timer_cnt {
> struct counter_device counter;
> struct regmap *regmap;
> struct clk *clk;
> u32 ceiling;
> + bool enabled;
> + struct stm32_timer_regs bak;
> };
>
> /**
> @@ -224,6 +234,9 @@ static ssize_t stm32_count_enable_write(struct counter_device *counter,
> clk_disable(priv->clk);
> }
>
> + /* Keep enabled state to properly handle low power states */
> + priv->enabled = enable;
> +
> return len;
> }
>
> @@ -358,10 +371,59 @@ 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);
> +
> + /* Only take care of enabled counter: don't disturb other MFD child */
> + if (priv->enabled) {
> + /* Backup registers that may get lost in low power mode */
> + regmap_read(priv->regmap, TIM_SMCR, &priv->bak.smcr);
> + regmap_read(priv->regmap, TIM_ARR, &priv->bak.arr);
> + regmap_read(priv->regmap, TIM_CNT, &priv->bak.cnt);
> + regmap_read(priv->regmap, TIM_CR1, &priv->bak.cr1);
> +
> + /* Disable the counter */
> + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
> + clk_disable(priv->clk);
> + }
> +
> + return pinctrl_pm_select_sleep_state(dev);
> +}
> +
> +static int __maybe_unused stm32_timer_cnt_resume(struct device *dev)
> +{
> + struct stm32_timer_cnt *priv = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = pinctrl_pm_select_default_state(dev);
> + if (ret)
> + return ret;
> +
> + if (priv->enabled) {
> + clk_enable(priv->clk);
> +
> + /* Restore registers that may have been lost */
> + regmap_write(priv->regmap, TIM_SMCR, priv->bak.smcr);
> + regmap_write(priv->regmap, TIM_ARR, priv->bak.arr);
> + regmap_write(priv->regmap, TIM_CNT, priv->bak.cnt);
> +
> + /* Also re-enables the counter */
> + regmap_write(priv->regmap, TIM_CR1, priv->bak.cr1);
> + }
> +
> + return 0;
> +}
> +
> +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 +435,7 @@ 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);