[PATCH] watchdog: rti: support SPL (or re-start)

[Stefan Roese]

Hi Alexander,

On 10.12.24 13:45, Sverdlin, Alexander wrote:
> Hi Stefan!
> 
> On Fri, 2024-11-08 at 22:15 +0100, A. Sverdlin wrote:
>> From: Alexander Sverdlin <alexander.sverdlin at siemens.com>
>>
>> If the RTI watchdog has been enabled in SPL, enabling it in U-Boot proper
>> fails because it can only be enabled once in HW and never stopped. This
>> however leads to a situation that wdt_cyclic() watchdog trigger is not
>> being started any longer and the WDT fires at some point.
>>
>> Allow for WDT re-start by not bailing out if the [previously] configured
>> period matches the one to be configured.
>>
>> Enabling in [A53] SPL has been tested on AM62x-based HW (where [A53] SPL is
>> responsible for loading R5 DM firmware and not this driver).
>>
>> Signed-off-by: Alexander Sverdlin <alexander.sverdlin at siemens.com>
> 
> I saw that this patch has been set to "Superseded" in the patchwork [1],
> but I'm not sure by which patch. Could it be that it happened by mistake?

Might be. I need to take a look...

> My other patch for the rti watchdog [2] is addressing some unrelated issue...
> 
> 1.
> https://patchwork.ozlabs.org/project/uboot/patch/20241108211506.1348528-1-alexander.sverdlin@siemens.com/
> 
> 2.
> https://patchwork.ozlabs.org/project/uboot/patch/20241120222412.1873381-1-alexander.sverdlin@siemens.com/
> https://patchwork.ozlabs.org/project/uboot/patch/20241121080326.1913067-1-alexander.sverdlin@siemens.com/

Sorry, I missed handling the watchdog patches in this release cycle.
And now we are pretty late in the release cycle and I would prefer
to defer pulling these patches after the upcoming release beginning
of January. Please excuse the inconvenience.

Thanks,
Stefan

>> ---
>>   drivers/watchdog/rti_wdt.c | 13 +++++++------
>>   1 file changed, 7 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c
>> index 99168d0cad03..320c5ca19e0a 100644
>> --- a/drivers/watchdog/rti_wdt.c
>> +++ b/drivers/watchdog/rti_wdt.c
>> @@ -131,18 +131,19 @@ static int rti_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
>>   	u32 timer_margin;
>>   	int ret;
>>   
>> -	if (readl(priv->regs + RTIDWDCTRL) == WDENABLE_KEY)
>> +	timer_margin = timeout_ms * priv->clk_hz / 1000;
>> +	timer_margin >>= WDT_PRELOAD_SHIFT;
>> +	if (timer_margin > WDT_PRELOAD_MAX)
>> +		timer_margin = WDT_PRELOAD_MAX;
>> +
>> +	if (readl(priv->regs + RTIDWDCTRL) == WDENABLE_KEY &&
>> +	    readl(priv->regs + RTIDWDPRLD) != timer_margin)
>>   		return -EBUSY;
>>   
>>   	ret = rti_wdt_load_fw(dev);
>>   	if (ret < 0)
>>   		return ret;
>>   
>> -	timer_margin = timeout_ms * priv->clk_hz / 1000;
>> -	timer_margin >>= WDT_PRELOAD_SHIFT;
>> -	if (timer_margin > WDT_PRELOAD_MAX)
>> -		timer_margin = WDT_PRELOAD_MAX;
>> -
>>   	writel(timer_margin, priv->regs + RTIDWDPRLD);
>>   	writel(RTIWWDRX_NMI, priv->regs + RTIWWDRXCTRL);
>>   	writel(RTIWWDSIZE_50P, priv->regs + RTIWWDSIZECTRL);
> 

Viele Grüße,
Stefan Roese

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