RE: [PATCH v9 2/2] rtc: max31335: add driver support

[Miclaus, Antoniu]

--
Antoniu Miclăuş

> -----Original Message-----
> From: Chris Packham <Chris.Packham@xxxxxxxxxxxxxxxxxxx>
> Sent: Monday, February 19, 2024 4:52 AM
> To: Miclaus, Antoniu <Antoniu.Miclaus@xxxxxxxxxx>; Alessandro Zummo
> <a.zummo@xxxxxxxxxxxx>; Alexandre Belloni
> <alexandre.belloni@xxxxxxxxxxx>; Rob Herring <robh+dt@xxxxxxxxxx>;
> Krzysztof Kozlowski <krzysztof.kozlowski+dt@xxxxxxxxxx>; Conor Dooley
> <conor+dt@xxxxxxxxxx>; Jean Delvare <jdelvare@xxxxxxxx>; Guenter Roeck
> <linux@xxxxxxxxxxxx>; linux-rtc@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; linux-hwmon@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v9 2/2] rtc: max31335: add driver support
> 
> [External]
> 
> Hi All,
> 
> I'm looking at folding this into the rest of the max313xx support (but
> I'll stick with the max31335 name since that's landed) and I noticed a
> problem.
> 
> On 21/11/23 01:00, Antoniu Miclaus wrote:
> > RTC driver for MAX31335 ±2ppm Automotive Real-Time Clock with
> > Integrated MEMS Resonator.
> >
> > Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> > Signed-off-by: Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx>
> <snip>
> > +
> > +static bool max31335_volatile_reg(struct device *dev, unsigned int reg)
> > +{
> > +	/* time keeping registers */
> > +	if (reg >= MAX31335_SECONDS &&
> > +	    reg < MAX31335_SECONDS + MAX31335_TIME_SIZE)
> > +		return true;
> > +
> > +	/* interrupt status register */
> > +	if (reg == MAX31335_INT_EN1_A1IE)
> > +		return true;
> Presumably this should be something else as MAX31335_INT_EN1_A1IE is a
> bitfield offset not a register.  Based on the other chips I'm guessing
> this should be `reg == MAX31335_STATUS1`. I'll try to incorporate a fix
> into my update but someone might want to fix it up for stable.

Indeed, MAX31335_STATUS1  should be used here. I re-checked the latest
datasheet that I have.

Thanks for pointing that out. 

I will add a patch soon.

> > +
> > +	/* temperature registers */
> > +	if (reg == MAX31335_TEMP_DATA_MSB ||
> MAX31335_TEMP_DATA_LSB)
> > +		return true;
> > +
> > +	return false;
> > +}
> > +