RE: [PATCH v4 1/2] drivers: watchdog: add a driver to support SAMA5D4 watchdog timer

[Yang, Wenyou]

Hi Guenter,

Thank you for your correct.

> -----Original Message-----
> From: Guenter Roeck [mailto:linux@xxxxxxxxxxxx]
> Sent: 2015年8月6日 16:05
> To: Yang, Wenyou; wim@xxxxxxxxx; robh+dt@xxxxxxxxxx; pawel.moll@xxxxxxx;
> mark.rutland@xxxxxxx; ijc+devicetree@xxxxxxxxxxxxxx; galak@xxxxxxxxxxxxxx
> Cc: sylvain.rochet@xxxxxxxxxxxx; Ferre, Nicolas; boris.brezillon@free-
> electrons.com; devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-
> watchdog@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH v4 1/2] drivers: watchdog: add a driver to support SAMA5D4
> watchdog timer
> 
> On 08/05/2015 09:59 PM, Wenyou Yang wrote:
> >>From SAMA5D4, the watchdog timer is upgrated with a new feature,
> > which is describled as in the datasheet, "WDT_MR can be written until
> > a LOCKMR command is issued in WDT_CR".
> > That is to say, as long as the bootstrap and u-boot don't issue a
> > LOCKMR command, WDT_MR can be written more than once in the driver.
> >
> > So the SAMA5D4 watchdog driver's implementation is different from the
> > at91sam9260 watchdog driver implemented in file at91sam9_wdt.c.
> > The user application open the device file to enable the watchdog timer
> > hardware, and close to disable it, and set the watchdog timer timeout
> > by seting WDV and WDD fields of WDT_MR register, and ping the watchdog
> > by issuing WDRSTT command to WDT_CR register with hard-coded key.
> >
> > Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxx>
> > ---
> [ ... ]
> > +
> > +/* minimum and maximum watchdog timeout, in seconds */
> > +#define	MIN_WDT_TIMEOUT		1
> > +#define	MAX_WDT_TIMEOUT		16
> > +#define	WDT_DEFAULT_TIMEOUT	MAX_WDT_TIMEOUT
> > +
> > +#define	WDT_SEC2TICKS(s)	((s) ? (((s) << 8) - 1) : 0)
> > +
> 
> Why did you replace the spaces after #define with tabs ?
> I understand this is done in the at91.h file, but that is bad enough, it doesn't add
> any value, and I don't see a reason to do it here.
Accepted, Using spaces, not tabs.

> 
> > +
> > +	if ((wdt->config & AT91_WDT_WDFIEN) && irq) {
> > +		ret = devm_request_irq(&pdev->dev, irq,
> sama5d4_wdt_irq_handler,
> > +				       0, pdev->name, pdev);
> 
> I just realized - this interrupt is registered with flags set to 0, while in the at91sam
> driver the flags are "IRQF_SHARED | IRQF_IRQPOLL | IRQF_NO_SUSPEND". Is
> this different with the new SOC ?
No, it is same. It is my carelessness.

> 
> Thanks,
> Guenter


Best Regards,
Wenyou Yang