[4/4] iio: counter: stm32-lptimer: Add power management support
diff mbox series

Message ID 1549370429-19116-5-git-send-email-fabrice.gasnier@st.com
State Superseded
Headers show
Series
  • Add PM support to STM32 LP Timer drivers
Related show

Commit Message

Fabrice Gasnier Feb. 5, 2019, 12:40 p.m. UTC
Add suspend/resume PM sleep ops. When going to low power, disable
active counter. Only active counter should be resumed: don't touch
disabled counter, as it may be used by other LPTimer MFD child driver.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
---
 drivers/iio/counter/stm32-lptimer-cnt.c | 55 +++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

Comments

Jonathan Cameron Feb. 9, 2019, 4:21 p.m. UTC | #1
On Tue, 5 Feb 2019 13:40:29 +0100
Fabrice Gasnier <fabrice.gasnier@st.com> wrote:

> Add suspend/resume PM sleep ops. When going to low power, disable
> active counter. Only active counter should be resumed: don't touch
> disabled counter, as it may be used by other LPTimer MFD child driver.
> 
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
I think this looks fine.  I'm not totally sure if patches 3,4 are
separable from 1,2 though so please let me know whether I should take
these now, or let all 4 go in together via some path?

Thanks,

Jonathan

> ---
>  drivers/iio/counter/stm32-lptimer-cnt.c | 55 +++++++++++++++++++++++++++++++++
>  1 file changed, 55 insertions(+)
> 
> diff --git a/drivers/iio/counter/stm32-lptimer-cnt.c b/drivers/iio/counter/stm32-lptimer-cnt.c
> index 42fb8ba..2a49cce 100644
> --- a/drivers/iio/counter/stm32-lptimer-cnt.c
> +++ b/drivers/iio/counter/stm32-lptimer-cnt.c
> @@ -14,6 +14,7 @@
>  #include <linux/iio/iio.h>
>  #include <linux/mfd/stm32-lptimer.h>
>  #include <linux/module.h>
> +#include <linux/pinctrl/consumer.h>
>  #include <linux/platform_device.h>
>  
>  struct stm32_lptim_cnt {
> @@ -23,6 +24,7 @@ struct stm32_lptim_cnt {
>  	u32 preset;
>  	u32 polarity;
>  	u32 quadrature_mode;
> +	bool enabled;
>  };
>  
>  static int stm32_lptim_is_enabled(struct stm32_lptim_cnt *priv)
> @@ -50,6 +52,7 @@ static int stm32_lptim_set_enable_state(struct stm32_lptim_cnt *priv,
>  
>  	if (!enable) {
>  		clk_disable(priv->clk);
> +		priv->enabled = false;
>  		return 0;
>  	}
>  
> @@ -79,6 +82,7 @@ static int stm32_lptim_set_enable_state(struct stm32_lptim_cnt *priv,
>  		regmap_write(priv->regmap, STM32_LPTIM_CR, 0);
>  		return ret;
>  	}
> +	priv->enabled = true;
>  
>  	/* Start LP timer in continuous mode */
>  	return regmap_update_bits(priv->regmap, STM32_LPTIM_CR,
> @@ -361,6 +365,56 @@ static int stm32_lptim_cnt_probe(struct platform_device *pdev)
>  	return devm_iio_device_register(&pdev->dev, indio_dev);
>  }
>  
> +#ifdef CONFIG_PM_SLEEP
> +static int stm32_lptim_cnt_suspend(struct device *dev)
> +{
> +	struct stm32_lptim_cnt *priv = dev_get_drvdata(dev);
> +	int ret;
> +
> +	/* Only take care of enabled counter: don't disturb other MFD child */
> +	if (priv->enabled) {
> +		ret = stm32_lptim_setup(priv, 0);
> +		if (ret)
> +			return ret;
> +
> +		ret = stm32_lptim_set_enable_state(priv, 0);
> +		if (ret)
> +			return ret;
> +
> +		/* Force enable state for later resume */
> +		priv->enabled = true;
> +	}
> +
> +	return pinctrl_pm_select_sleep_state(dev);
> +}
> +
> +static int stm32_lptim_cnt_resume(struct device *dev)
> +{
> +	struct stm32_lptim_cnt *priv = dev_get_drvdata(dev);
> +	int ret;
> +
> +	ret = pinctrl_pm_select_default_state(dev);
> +	if (ret)
> +		return ret;
> +
> +	if (priv->enabled) {
> +		priv->enabled = false;
> +		ret = stm32_lptim_setup(priv, 1);
> +		if (ret)
> +			return ret;
> +
> +		ret = stm32_lptim_set_enable_state(priv, 1);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +#endif
> +
> +static SIMPLE_DEV_PM_OPS(stm32_lptim_cnt_pm_ops, stm32_lptim_cnt_suspend,
> +			 stm32_lptim_cnt_resume);
> +
>  static const struct of_device_id stm32_lptim_cnt_of_match[] = {
>  	{ .compatible = "st,stm32-lptimer-counter", },
>  	{},
> @@ -372,6 +426,7 @@ static int stm32_lptim_cnt_probe(struct platform_device *pdev)
>  	.driver = {
>  		.name = "stm32-lptimer-counter",
>  		.of_match_table = stm32_lptim_cnt_of_match,
> +		.pm = &stm32_lptim_cnt_pm_ops,
>  	},
>  };
>  module_platform_driver(stm32_lptim_cnt_driver);
Uwe Kleine-König Feb. 10, 2019, 9:33 p.m. UTC | #2
On Sat, Feb 09, 2019 at 04:21:33PM +0000, Jonathan Cameron wrote:
> On Tue, 5 Feb 2019 13:40:29 +0100
> Fabrice Gasnier <fabrice.gasnier@st.com> wrote:
> 
> > Add suspend/resume PM sleep ops. When going to low power, disable
> > active counter. Only active counter should be resumed: don't touch
> > disabled counter, as it may be used by other LPTimer MFD child driver.
> > 
> > Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
> I think this looks fine.  I'm not totally sure if patches 3,4 are
> separable from 1,2 though so please let me know whether I should take
> these now, or let all 4 go in together via some path?

I'd say these are orthogonal, so if you are happy with patches 3 and 4
you can take them without bothering for patches 1 and 2.

Best regards
Uwe
Fabrice Gasnier Feb. 11, 2019, 1:21 p.m. UTC | #3
On 2/10/19 10:33 PM, Uwe Kleine-König wrote:
> On Sat, Feb 09, 2019 at 04:21:33PM +0000, Jonathan Cameron wrote:
>> On Tue, 5 Feb 2019 13:40:29 +0100
>> Fabrice Gasnier <fabrice.gasnier@st.com> wrote:
>>
>>> Add suspend/resume PM sleep ops. When going to low power, disable
>>> active counter. Only active counter should be resumed: don't touch
>>> disabled counter, as it may be used by other LPTimer MFD child driver.
>>>
>>> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
>> I think this looks fine.  I'm not totally sure if patches 3,4 are
>> separable from 1,2 though so please let me know whether I should take
>> these now, or let all 4 go in together via some path?
> 
> I'd say these are orthogonal, so if you are happy with patches 3 and 4
> you can take them without bothering for patches 1 and 2.

Hi Uwe, Jonathan,

Thanks for reviewing. I confirm you can take patches 3 and 4. I'll send
a v2 for patches 1 and 2 separately.

Best regards,
Fabrice

> 
> Best regards
> Uwe
>

Patch
diff mbox series

diff --git a/drivers/iio/counter/stm32-lptimer-cnt.c b/drivers/iio/counter/stm32-lptimer-cnt.c
index 42fb8ba..2a49cce 100644
--- a/drivers/iio/counter/stm32-lptimer-cnt.c
+++ b/drivers/iio/counter/stm32-lptimer-cnt.c
@@ -14,6 +14,7 @@ 
 #include <linux/iio/iio.h>
 #include <linux/mfd/stm32-lptimer.h>
 #include <linux/module.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
 
 struct stm32_lptim_cnt {
@@ -23,6 +24,7 @@  struct stm32_lptim_cnt {
 	u32 preset;
 	u32 polarity;
 	u32 quadrature_mode;
+	bool enabled;
 };
 
 static int stm32_lptim_is_enabled(struct stm32_lptim_cnt *priv)
@@ -50,6 +52,7 @@  static int stm32_lptim_set_enable_state(struct stm32_lptim_cnt *priv,
 
 	if (!enable) {
 		clk_disable(priv->clk);
+		priv->enabled = false;
 		return 0;
 	}
 
@@ -79,6 +82,7 @@  static int stm32_lptim_set_enable_state(struct stm32_lptim_cnt *priv,
 		regmap_write(priv->regmap, STM32_LPTIM_CR, 0);
 		return ret;
 	}
+	priv->enabled = true;
 
 	/* Start LP timer in continuous mode */
 	return regmap_update_bits(priv->regmap, STM32_LPTIM_CR,
@@ -361,6 +365,56 @@  static int stm32_lptim_cnt_probe(struct platform_device *pdev)
 	return devm_iio_device_register(&pdev->dev, indio_dev);
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int stm32_lptim_cnt_suspend(struct device *dev)
+{
+	struct stm32_lptim_cnt *priv = dev_get_drvdata(dev);
+	int ret;
+
+	/* Only take care of enabled counter: don't disturb other MFD child */
+	if (priv->enabled) {
+		ret = stm32_lptim_setup(priv, 0);
+		if (ret)
+			return ret;
+
+		ret = stm32_lptim_set_enable_state(priv, 0);
+		if (ret)
+			return ret;
+
+		/* Force enable state for later resume */
+		priv->enabled = true;
+	}
+
+	return pinctrl_pm_select_sleep_state(dev);
+}
+
+static int stm32_lptim_cnt_resume(struct device *dev)
+{
+	struct stm32_lptim_cnt *priv = dev_get_drvdata(dev);
+	int ret;
+
+	ret = pinctrl_pm_select_default_state(dev);
+	if (ret)
+		return ret;
+
+	if (priv->enabled) {
+		priv->enabled = false;
+		ret = stm32_lptim_setup(priv, 1);
+		if (ret)
+			return ret;
+
+		ret = stm32_lptim_set_enable_state(priv, 1);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(stm32_lptim_cnt_pm_ops, stm32_lptim_cnt_suspend,
+			 stm32_lptim_cnt_resume);
+
 static const struct of_device_id stm32_lptim_cnt_of_match[] = {
 	{ .compatible = "st,stm32-lptimer-counter", },
 	{},
@@ -372,6 +426,7 @@  static int stm32_lptim_cnt_probe(struct platform_device *pdev)
 	.driver = {
 		.name = "stm32-lptimer-counter",
 		.of_match_table = stm32_lptim_cnt_of_match,
+		.pm = &stm32_lptim_cnt_pm_ops,
 	},
 };
 module_platform_driver(stm32_lptim_cnt_driver);