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

[Pali Rohár]

On Tuesday 09 March 2021 12:33:24 Stefan Roese wrote:
> 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

I have fixed these issues in V2.