On Fri, Jan 8, 2021 at 4:49 PM Luca Ceresoli <luca@xxxxxxxxxxxxxxxx> wrote: > > Hi Adam, > > On 06/01/21 18:38, Adam Ford wrote: > > There are two registers which can set the load capacitance for > > XTAL1 and XTAL2. These are optional registers when using an > > external crystal. Update the bindings to support them. > > > > Signed-off-by: Adam Ford <aford173@xxxxxxxxx> > > --- > > .../devicetree/bindings/clock/idt,versaclock5.yaml | 12 ++++++++++++ > > 1 file changed, 12 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/clock/idt,versaclock5.yaml b/Documentation/devicetree/bindings/clock/idt,versaclock5.yaml > > index 2ac1131fd922..e5e55ffb266e 100644 > > --- a/Documentation/devicetree/bindings/clock/idt,versaclock5.yaml > > +++ b/Documentation/devicetree/bindings/clock/idt,versaclock5.yaml > > @@ -59,6 +59,18 @@ properties: > > minItems: 1 > > maxItems: 2 > > > > + idt,xtal1-load-femtofarads: > > I wonder whether we should have a common, vendor independent property. That would be nice. > In mainline we have xtal-load-pf (ti,cdce925.txt bindings) which has no > vendor prefix. However I don't know how much common it is to need rtc-pcf85063.c uses quartz-load-femtofarads, so there is already some discrepancy. Since the unit of measure here is femtofarads, using pF in the name seems wrong. We need to read the data as a u32, so femtofarads works better than pF, which would require a decimal point. > different loads for x1 and x2. Any hardware engineer around? I talked to a hardware engineer where I work, and he said it makes sense to keep them the same. I only separated them because there are two registers, and I assumed there might be a reason to have X1 and X2 be different, but I'm ok with reading one value and writing it to two different registers. adam > > > + $ref: /schemas/types.yaml#/definitions/uint32 > > + minimum: 9000 > > + maximum: 25000 > > + description: Optional loading capacitor for XTAL1 > > Nit: I think the common wording is "load capacitor", not "loading > capacitor". > > -- > Luca
