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SubjectRe: [PATCH v1 1/5] dt-binding: rtci-pcf8523: add quartz_load property
On 26/09/2018 10:47:08-0500, Rob Herring wrote:
> > > +Optional property:
> > > +- nxp,quartz_load_12.5pF: The capacitive load on the quartz is 12.5 pF,
> > > + which differ from the default value of 7 pF
> > > +
> >
> > The boolean properties usually don't work well for RTCs because people
> > usually want to keep any previous configuration that may have been done
> > at the factory or in the bootloader so I would use:
> >
> > nxp,quartz_load_fF and this would be either 7000 or 12500.
>
> Use '-' rather than '_'.
>
> There's already a defined unit suffix of '-picofarads'. If you need
> '-femtofarads', then please add to property-units.txt. Though I'd prefer
> not as wouldn't a value of 12 (or 13) be close enough for the needs
> here?
>

For that particular RTC, yes but the isl1208 has 0.5pF steps and the
x1205 has 0.25pf steps. I'd prefer having a single generic property for
all the RTCs: quartz-load-femtofarads.

--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

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