[PATCH v5 3/5] watchdog: da9062: reset board on watchdog timeout

[Christoph Niedermaier]

From: Andrej Picej
Sent: Monday, December 6, 2021 7:48 AM
> Implement a method to change watchdog timeout configuration based on DT
> binding ("dlg,wdt-sd"). There is a possibility to change the behaviour
> 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 da9061/2 multi function device.
> 
> Signed-off-by: Andrej Picej <andrej.picej at norik.com>
> ---
> Changes in v5:
>  - fix spelling mistake in commit message
> 
> Changes in v4:
>  - move the code to probe function
> 
> Changes in v3:
>  - no changes
> 
> Changes in v2:
>  - don't force the "reset" for all da9062-watchdog users, instead add DT
>    binding where the behavior can be selected
> ---
>  drivers/watchdog/da9062_wdt.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/drivers/watchdog/da9062_wdt.c b/drivers/watchdog/da9062_wdt.c
> index f02cbd530538..bd85f84b0fd4 100644
> --- a/drivers/watchdog/da9062_wdt.c
> +++ b/drivers/watchdog/da9062_wdt.c
> @@ -195,8 +195,11 @@ static int da9062_wdt_probe(struct platform_device
> *pdev)
>  {
>         struct device *dev = &pdev->dev;
>         unsigned int timeout;
> +       unsigned int mask;
>         struct da9062 *chip;
>         struct da9062_watchdog *wdt;
> +       int ret;
> +       u32 val;
> 
>         chip = dev_get_drvdata(dev->parent);
>         if (!chip)
> @@ -236,6 +239,30 @@ static int da9062_wdt_probe(struct platform_device
> *pdev)
>                 set_bit(WDOG_HW_RUNNING, &wdt->wdtdev.status);
>         }
> 
> +       /*
> +        * 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(dev, "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(dev, "failed to set wdt reset mode: %d\n",
> +                               ret);
> +       }
> +
>         return devm_watchdog_register_device(dev, &wdt->wdtdev);
>  }
> 
> --
> 2.25.1

Tested-by: Christoph Niedermaier <cniedermaier at dh-electronics.com>

Thanks and regards
Christoph