[PATCH v2] pwm: bcm2835: Add support for suspend/resume

[PATCH v2] pwm: bcm2835: Add support for suspend/resume

[Florian Fainelli]

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Similar to other drivers, we need to make sure that the clock is
disabled during suspend and re-enabled during resume.

Reported-by: Angus Clark <angus.clark@broadcom.com>
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
---
Changes in v2:

- use DEFINE_SIMPLE_DEV_PM_OPS as suggested by Uwe

 drivers/pwm/pwm-bcm2835.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c
index bdfc2a5ec0d6..938f993ae746 100644
--- a/drivers/pwm/pwm-bcm2835.c
+++ b/drivers/pwm/pwm-bcm2835.c
@@ -182,6 +182,25 @@ static void bcm2835_pwm_remove(struct platform_device *pdev)
 	clk_disable_unprepare(pc->clk);
 }
 
+static int __maybe_unused bcm2835_pwm_suspend(struct device *dev)
+{
+	struct bcm2835_pwm *pc = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(pc->clk);
+
+	return 0;
+}
+
+static int __maybe_unused bcm2835_pwm_resume(struct device *dev)
+{
+	struct bcm2835_pwm *pc = dev_get_drvdata(dev);
+
+	return clk_prepare_enable(pc->clk);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(bcm2835_pwm_pm_ops, bcm2835_pwm_suspend,
+				bcm2835_pwm_resume);
+
 static const struct of_device_id bcm2835_pwm_of_match[] = {
 	{ .compatible = "brcm,bcm2835-pwm", },
 	{ /* sentinel */ }
@@ -192,6 +211,7 @@ static struct platform_driver bcm2835_pwm_driver = {
 	.driver = {
 		.name = "bcm2835-pwm",
 		.of_match_table = bcm2835_pwm_of_match,
+		.pm = &bcm2835_pwm_pm_ops,
 	},
 	.probe = bcm2835_pwm_probe,
 	.remove_new = bcm2835_pwm_remove,
-- 
2.34.1


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Re: [PATCH v2] pwm: bcm2835: Add support for suspend/resume

[Uwe Kleine-König]

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On Mon, Oct 09, 2023 at 01:42:26PM -0700, Florian Fainelli wrote:
> Similar to other drivers, we need to make sure that the clock is
> disabled during suspend and re-enabled during resume.
> 
> Reported-by: Angus Clark <angus.clark@broadcom.com>
> Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
> ---
> Changes in v2:
> 
> - use DEFINE_SIMPLE_DEV_PM_OPS as suggested by Uwe
> 
>  drivers/pwm/pwm-bcm2835.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c
> index bdfc2a5ec0d6..938f993ae746 100644
> --- a/drivers/pwm/pwm-bcm2835.c
> +++ b/drivers/pwm/pwm-bcm2835.c
> @@ -182,6 +182,25 @@ static void bcm2835_pwm_remove(struct platform_device *pdev)
>  	clk_disable_unprepare(pc->clk);
>  }
>  
> +static int __maybe_unused bcm2835_pwm_suspend(struct device *dev)
> +{
> +	struct bcm2835_pwm *pc = dev_get_drvdata(dev);
> +
> +	clk_disable_unprepare(pc->clk);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused bcm2835_pwm_resume(struct device *dev)

With DEFINE_SIMPLE_DEV_PM_OPS you don't need the __maybe_unused (which
is one of the upsides of DEFINE_SIMPLE_DEV_PM_OPS compared to
SIMPLE_DEV_PM_OPS)

> +{
> +	struct bcm2835_pwm *pc = dev_get_drvdata(dev);
> +
> +	return clk_prepare_enable(pc->clk);
> +}
> +
> +static DEFINE_SIMPLE_DEV_PM_OPS(bcm2835_pwm_pm_ops, bcm2835_pwm_suspend,
> +				bcm2835_pwm_resume);
> +
>  static const struct of_device_id bcm2835_pwm_of_match[] = {
>  	{ .compatible = "brcm,bcm2835-pwm", },
>  	{ /* sentinel */ }
> @@ -192,6 +211,7 @@ static struct platform_driver bcm2835_pwm_driver = {
>  	.driver = {
>  		.name = "bcm2835-pwm",
>  		.of_match_table = bcm2835_pwm_of_match,
> +		.pm = &bcm2835_pwm_pm_ops,

I think 

+		.pm = pm_ptr(&bcm2835_pwm_pm_ops),

is the right thing here.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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