[PATCH 3/4] watchdog: Allow to use CONFIG_WDT without starting watchdog

[Stefan Roese]

On 05.03.21 22:36, Pali Rohár wrote:
> In some cases it is useful to compile support for U-Boot command 'wdt'
> without starting HW watchdog in early U-Boot phase. For example when user

Nitpicking:
   when "the" user

> want to start watchdog only on demand by some boot script.
> 
> This change adds a new compile option WATCHDOG_AUTOSTART to control whether
> U-Boot should automatically start watchdog during init phase or not.

   start "the" watchdog

> 
> This option is enabled by default as it was was default behavior prior

   as it was the default

> introducing this new change. When compiling U-Boot users can decide to turn
> this option off.
> 
> Signed-off-by: Pali Rohár <pali at kernel.org>
> ---
>   drivers/watchdog/Kconfig      | 13 +++++++++++++
>   drivers/watchdog/wdt-uclass.c |  7 +++++++
>   2 files changed, 20 insertions(+)
> 
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 602ccbe41c00..aa76a8f2d239 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -9,6 +9,19 @@ config WATCHDOG
>   	  this option if you want to service enabled watchdog by U-Boot. Disable
>   	  this option if you want U-Boot to start watchdog but never service it.
>   
> +config WATCHDOG_AUTOSTART
> +	bool "Automatically start watchdog timer"
> +	depends on WDT
> +	default y
> +	help
> +	  Automatically start watchdog timer and start servicing it during
> +	  init phase. Enabled by default. Disable this option if you want
> +	  to compile U-Boot with CONFIG_WDT support but do not want to
> +	  activate watchdog, like when CONFIG_WDT option is disabled. You
> +	  would be able to start watchdog manually by 'wdt' command. Useful
> +	  when you want to have support for 'wdt' command but do not want
> +	  to have watchdog enabled by default.
> +
>   config WATCHDOG_TIMEOUT_MSECS
>   	int "Watchdog timeout in msec"
>   	default 128000 if ARCH_MX25 || ARCH_MX31 || ARCH_MX5 || ARCH_MX6
> diff --git a/drivers/watchdog/wdt-uclass.c b/drivers/watchdog/wdt-uclass.c
> index 7500b3ed90e3..00a408bf5cc5 100644
> --- a/drivers/watchdog/wdt-uclass.c
> +++ b/drivers/watchdog/wdt-uclass.c
> @@ -27,7 +27,9 @@ static ulong reset_period = 1000;
>   int initr_watchdog(void)
>   {
>   	u32 timeout = WATCHDOG_TIMEOUT_SECS;
> +#ifdef CONFIG_WATCHDOG_AUTOSTART
>   	int ret;
> +#endif

Please don't add more #ifdef's if possible, see below...

>   
>   	/*
>   	 * Init watchdog: This will call the probe function of the
> @@ -51,6 +53,10 @@ int initr_watchdog(void)
>   						    4 * reset_period) / 4;
>   	}
>   
> +#ifndef CONFIG_WATCHDOG_AUTOSTART
> +	printf("WDT:   Not starting\n");
> +	return 0;
> +#else
>   	ret = wdt_start(gd->watchdog_dev, timeout * 1000, 0);
>   	if (ret != 0) {
>   		printf("WDT:   Failed to start\n");
> @@ -61,6 +67,7 @@ int initr_watchdog(void)
>   	       IS_ENABLED(CONFIG_WATCHDOG) ? "" : "out", timeout);
>   
>   	return 0;
> +#endif

Please use this instead here:

	if (CONFIG_IS_ENABLED(WATCHDOG_AUTOSTART)) {
	...

Thanks,
Stefan

>   }
>   
>   int wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
> 


Viele Grüße,
Stefan

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