2024-04-10 16:43:10

by Guenter Roeck

[permalink] [raw]
Subject: Re: [PATCH RESEND v8 08/10] watchdog: rzg2l_wdt: Add suspend/resume support

On Wed, Apr 10, 2024 at 04:40:42PM +0300, Claudiu wrote:
> From: Claudiu Beznea <[email protected]>
>
> The RZ/G3S supports deep sleep states where power to most of the IP blocks
> is cut off. To ensure proper working of the watchdog when resuming from
> such states, the suspend function is stopping the watchdog and the resume
> function is starting it. There is no need to configure the watchdog
> in case the watchdog was stopped prior to starting suspend.
>
> Signed-off-by: Claudiu Beznea <[email protected]>

Reviewed-by: Guenter Roeck <[email protected]>

> ---
>
> Changes in v8:
> - none
>
> Changes in v7:
> - none
>
> Changes in v6:
> - none
>
> Changes in v5:
> - none
>
> Changes in v4:
> - none
>
> Changes in v3:
> - none
>
> Changes in v2:
> - remove the usage of pm_ptr()
>
>
> drivers/watchdog/rzg2l_wdt.c | 26 ++++++++++++++++++++++++++
> 1 file changed, 26 insertions(+)
>
> diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
> index 42f1d5d6f07e..c8c20cfb97a3 100644
> --- a/drivers/watchdog/rzg2l_wdt.c
> +++ b/drivers/watchdog/rzg2l_wdt.c
> @@ -284,6 +284,7 @@ static int rzg2l_wdt_probe(struct platform_device *pdev)
> priv->wdev.timeout = WDT_DEFAULT_TIMEOUT;
>
> watchdog_set_drvdata(&priv->wdev, priv);
> + dev_set_drvdata(dev, priv);
> ret = devm_add_action_or_reset(&pdev->dev, rzg2l_wdt_pm_disable, &priv->wdev);
> if (ret)
> return ret;
> @@ -305,10 +306,35 @@ static const struct of_device_id rzg2l_wdt_ids[] = {
> };
> MODULE_DEVICE_TABLE(of, rzg2l_wdt_ids);
>
> +static int rzg2l_wdt_suspend_late(struct device *dev)
> +{
> + struct rzg2l_wdt_priv *priv = dev_get_drvdata(dev);
> +
> + if (!watchdog_active(&priv->wdev))
> + return 0;
> +
> + return rzg2l_wdt_stop(&priv->wdev);
> +}
> +
> +static int rzg2l_wdt_resume_early(struct device *dev)
> +{
> + struct rzg2l_wdt_priv *priv = dev_get_drvdata(dev);
> +
> + if (!watchdog_active(&priv->wdev))
> + return 0;
> +
> + return rzg2l_wdt_start(&priv->wdev);
> +}
> +
> +static const struct dev_pm_ops rzg2l_wdt_pm_ops = {
> + LATE_SYSTEM_SLEEP_PM_OPS(rzg2l_wdt_suspend_late, rzg2l_wdt_resume_early)
> +};
> +
> static struct platform_driver rzg2l_wdt_driver = {
> .driver = {
> .name = "rzg2l_wdt",
> .of_match_table = rzg2l_wdt_ids,
> + .pm = &rzg2l_wdt_pm_ops,
> },
> .probe = rzg2l_wdt_probe,
> };
> --
> 2.39.2
>