Subject: Re: [PATCH v2 2/4] watchdog: da9062: reset board on watchdog timeout
Cc:     support.opensource@diasemi.com, wim@linux-watchdog.org,
        linux@roeck-us.net, linux-watchdog@vger.kernel.org,
        linux-kernel@vger.kernel.org, robh+dt@kernel.org,
        devicetree@vger.kernel.org, shawnguo@kernel.org,
        s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com,
        linux-imx@nxp.com, linux-arm-kernel@lists.infradead.org
References: <20211130134242.3516619-1-andrej.picej@norik.com>
 <20211130134242.3516619-2-andrej.picej@norik.com>
From:   Andrej Picej <andrej.picej@norik.com>
Message-ID: <64c5fb81-8cfd-e5a6-7d13-e17e88e4964d@norik.com>
Date:   Tue, 30 Nov 2021 14:54:01 +0100
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On 30. 11. 21 14:42, Andrej Picej wrote:
> Implement a method to change watchdog timeout configuration based on DT
> binding ("dlg,wdt-sd"). There is a possibility to change the bahaviour
> of watchdog reset. Setting WATCHDOG_SD bit enables SHUTDOWN mode, and
> clearing it enables POWERDOWN mode on watchdog timeout.
> 
> If no DT binding is specified the WATCHDOG_SD bit stays in default
> configuration, not breaking behaviour of devices which might depend on
> default fuse configuration.
> 
> Note: This patch requires that the config register CONFIG_I is
> configured as writable in the da9062 multi function device.
> 
> Signed-off-by: Andrej Picej <andrej.picej@norik.com>
> ---
>   drivers/watchdog/da9062_wdt.c | 25 +++++++++++++++++++++++++
>   1 file changed, 25 insertions(+)
> 
> diff --git a/drivers/watchdog/da9062_wdt.c b/drivers/watchdog/da9062_wdt.c
> index f02cbd530538..e342e9e50cb1 100644
> --- a/drivers/watchdog/da9062_wdt.c
> +++ b/drivers/watchdog/da9062_wdt.c
> @@ -85,8 +85,33 @@ static int da9062_wdt_start(struct watchdog_device *wdd)
>   {
>   	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
>   	unsigned int selector;
> +	unsigned int mask;
> +	u32 val;
>   	int ret;
>   
> +	/* Configure what happens on watchdog timeout. Can be specified with
> +	 * "dlg,wdt-sd" dt-binding (0 -> POWERDOWN, 1 -> SHUTDOWN).
> +	 * If "dlg,wdt-sd" dt-binding is NOT set use the default.
> +	 */
> +	ret = device_property_read_u32(wdd->parent, "dlg,wdt-sd", &val);
> +	if (!ret) {
> +		if (val)
> +			/* Use da9062's SHUTDOWN mode */
> +			mask = DA9062AA_WATCHDOG_SD_MASK;
> +		else
> +			/* Use da9062's POWERDOWN mode. */
> +			mask = 0x0;
> +
> +		ret = regmap_update_bits(wdt->hw->regmap,
> +						DA9062AA_CONFIG_I,
> +						DA9062AA_WATCHDOG_SD_MASK,
> +						mask);
> +
> +		if (ret)
> +			dev_err(wdt->hw->dev, "failed to set wdt reset mode: %d\n",
> +				ret);
> +	}
> +
>   	selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
>   	ret = da9062_wdt_update_timeout_register(wdt, selector);
>   	if (ret)
> 

Changes in v2:
- don't force the "reset" for all da9062-watchdog users, instead add DT 
binding where the behavior can be selected