Re: [PATCH v5 7/7] watchdog: rzg2l_wdt: Add set_timeout callback

[Guenter Roeck <linux@roeck-us.net>]

On Fri, Feb 25, 2022 at 05:53:20PM +0000, Biju Das wrote:
> This patch adds support for set_timeout callback.
> 
> Once WDT is started, the WDT cycle setting register(WDTSET) can be updated
> only after issuing a module reset. Otherwise, it will ignore the writes
> and will hold the previous value. This patch updates the WDTSET register
> if it is active.
> 
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

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

> ---
> V4->V5:
>  * Added Rb tag from Geert.
> V3->v4:
>  * Updated commit description
>  * Simplified the logic for updating timeout register, if wdt is active.
> v2->v3:
>  * Patch reodering Patch 3 -> patch 4
>  * Updated commit description.
> V1->V2:
>  * Updated commit description
>  * Removed stop/start and started using reset() instead.
>  * After reset, Start WDT based on watchdog timer state.
> ---
>  drivers/watchdog/rzg2l_wdt.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
> index 4e7107655cc2..6eea0ee4af49 100644
> --- a/drivers/watchdog/rzg2l_wdt.c
> +++ b/drivers/watchdog/rzg2l_wdt.c
> @@ -115,6 +115,25 @@ static int rzg2l_wdt_stop(struct watchdog_device *wdev)
>  	return 0;
>  }
>  
> +static int rzg2l_wdt_set_timeout(struct watchdog_device *wdev, unsigned int timeout)
> +{
> +	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
> +
> +	wdev->timeout = timeout;
> +
> +	/*
> +	 * If the watchdog is active, reset the module for updating the WDTSET
> +	 * register so that it is updated with new timeout values.
> +	 */
> +	if (watchdog_active(wdev)) {
> +		pm_runtime_put(wdev->parent);
> +		reset_control_reset(priv->rstc);
> +		rzg2l_wdt_start(wdev);
> +	}
> +
> +	return 0;
> +}
> +
>  static int rzg2l_wdt_restart(struct watchdog_device *wdev,
>  			     unsigned long action, void *data)
>  {
> @@ -151,6 +170,7 @@ static const struct watchdog_ops rzg2l_wdt_ops = {
>  	.start = rzg2l_wdt_start,
>  	.stop = rzg2l_wdt_stop,
>  	.ping = rzg2l_wdt_ping,
> +	.set_timeout = rzg2l_wdt_set_timeout,
>  	.restart = rzg2l_wdt_restart,
>  };
>  
> -- 
> 2.17.1
>