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Sender: Guenter Roeck <groeck7@gmail.com>
Date: Wed, 10 Apr 2024 09:42:48 -0700
From: Guenter Roeck <linux@roeck-us.net>
To: Claudiu <claudiu.beznea@tuxon.dev>
Cc: wim@linux-watchdog.org, robh@kernel.org, krzk+dt@kernel.org,
	conor+dt@kernel.org, p.zabel@pengutronix.de,
	geert+renesas@glider.be, magnus.damm@gmail.com,
	biju.das.jz@bp.renesas.com, linux-watchdog@vger.kernel.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-renesas-soc@vger.kernel.org,
	Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Subject: Re: [PATCH RESEND v8 08/10] watchdog: rzg2l_wdt: Add suspend/resume
 support
Message-ID: <aa9bbd1c-a17b-4364-b6fd-b94749d4e068@roeck-us.net>
References: <20240410134044.2138310-1-claudiu.beznea.uj@bp.renesas.com>
 <20240410134044.2138310-9-claudiu.beznea.uj@bp.renesas.com>
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In-Reply-To: <20240410134044.2138310-9-claudiu.beznea.uj@bp.renesas.com>

On Wed, Apr 10, 2024 at 04:40:42PM +0300, Claudiu wrote:
> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> 
> 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 <claudiu.beznea.uj@bp.renesas.com>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
> 
> 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
>