Re: [PATCH 2/3] watchdog: da9063: optionally disable watchdog during suspend

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

On Fri, Apr 22, 2022 at 09:27:12AM +0200, Primoz Fiser wrote:
> Optionally disable watchdog during suspend (if enabled) and re-enable
> it upon resume.
> This enables boards to sleep without being interrupted by the watchdog.
> 
> This patch is based on commit f6c98b08381c ("watchdog: da9062: add
> power management ops") and commit 8541673d2a5f ("watchdog: da9062: fix
> power management ops") and brings the same functionality to DA9063.
> 
> Signed-off-by: Primoz Fiser <primoz.fiser@norik.com>
> Reviewed-by: Adam Thomson <DLG-Adam.Thomson.Opensource@dm.renesas.com>

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

> ---
>  drivers/watchdog/da9063_wdt.c | 36 +++++++++++++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
> 
> diff --git a/drivers/watchdog/da9063_wdt.c b/drivers/watchdog/da9063_wdt.c
> index 9adad1862bbd..09a4af4c58fc 100644
> --- a/drivers/watchdog/da9063_wdt.c
> +++ b/drivers/watchdog/da9063_wdt.c
> @@ -18,6 +18,7 @@
>  #include <linux/delay.h>
>  #include <linux/mfd/da9063/registers.h>
>  #include <linux/mfd/da9063/core.h>
> +#include <linux/property.h>
>  #include <linux/regmap.h>
>  
>  /*
> @@ -26,6 +27,8 @@
>   *   others: timeout = 2048 ms * 2^(TWDSCALE-1).
>   */
>  static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
> +static bool use_sw_pm;
> +
>  #define DA9063_TWDSCALE_DISABLE		0
>  #define DA9063_TWDSCALE_MIN		1
>  #define DA9063_TWDSCALE_MAX		(ARRAY_SIZE(wdt_timeout) - 1)
> @@ -218,6 +221,8 @@ static int da9063_wdt_probe(struct platform_device *pdev)
>  	if (!wdd)
>  		return -ENOMEM;
>  
> +	use_sw_pm = device_property_present(dev, "dlg,use-sw-pm");
> +
>  	wdd->info = &da9063_watchdog_info;
>  	wdd->ops = &da9063_watchdog_ops;
>  	wdd->min_timeout = DA9063_WDT_MIN_TIMEOUT;
> @@ -228,6 +233,7 @@ static int da9063_wdt_probe(struct platform_device *pdev)
>  
>  	watchdog_set_restart_priority(wdd, 128);
>  	watchdog_set_drvdata(wdd, da9063);
> +	dev_set_drvdata(dev, wdd);
>  
>  	wdd->timeout = DA9063_WDG_TIMEOUT;
>  
> @@ -249,10 +255,40 @@ static int da9063_wdt_probe(struct platform_device *pdev)
>  	return devm_watchdog_register_device(dev, wdd);
>  }
>  
> +static int __maybe_unused da9063_wdt_suspend(struct device *dev)
> +{
> +	struct watchdog_device *wdd = dev_get_drvdata(dev);
> +
> +	if (!use_sw_pm)
> +		return 0;
> +
> +	if (watchdog_active(wdd))
> +		return da9063_wdt_stop(wdd);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused da9063_wdt_resume(struct device *dev)
> +{
> +	struct watchdog_device *wdd = dev_get_drvdata(dev);
> +
> +	if (!use_sw_pm)
> +		return 0;
> +
> +	if (watchdog_active(wdd))
> +		return da9063_wdt_start(wdd);
> +
> +	return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(da9063_wdt_pm_ops,
> +			da9063_wdt_suspend, da9063_wdt_resume);
> +
>  static struct platform_driver da9063_wdt_driver = {
>  	.probe = da9063_wdt_probe,
>  	.driver = {
>  		.name = DA9063_DRVNAME_WATCHDOG,
> +		.pm = &da9063_wdt_pm_ops,
>  	},
>  };
>  module_platform_driver(da9063_wdt_driver);