On Wed, Oct 18, 2023 at 11:53 AM Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> wrote: > On 18/10/2023 10:18, Linus Walleij wrote: > > On Mon, Oct 16, 2023 at 9:52 PM Krzysztof Kozlowski > > <krzysztof.kozlowski@xxxxxxxxxx> wrote: > > > >>> I noticed that 'xlnx,zynq-pinctrl.yaml' and 'xlnx,zynq-pinctrl.yaml' use > >>> 'power source' to specify the output voltage. Should I follow their > >>> approach or define a vendor-specific one? > >> > >> Maybe Rob or Linus have here some recommendation, but I would suggest to > >> go either with rtd1319d-pinctrl.yaml approach or add a generic property > >> to pincfg-node expressed in real units like "io-microvolt". > >> > >> Rob, Linus, any ideas for generic property replacing register-specific > >> power-source? > > > > The existing power-source is generally used to select between (usually > > two) different chip-internal power rails, such as 1.8V and 3.3V. > > The format is a driver-specific enumerator. > > > > We *could* just patch the documentation for power-source to > > say that microvolts is the preferred format but legacy users may > > be using a custom enumerator. > > > > io-microvolt seems like a more long-term viable option if a wider > > range of voltages are to be supported so I'm happy with that if the > > DT folks think it's nicer. However notice that the power-source > > property is already being hard-coded into things such as SCMI > > and ACPI so it's not like it will ever be replaced by io-microvolt > > and phased out as far as Linux is concerned. Not the next 50 > > years at least. > > This I understand. > > I think It is better in general if generic properties use units (e.g. > drive-strength-microamp, output-impedance-ohms), so it could be here > "io-microvolt". At least for the new bindings. I agree. Even io-voltage-microvolt perhaps. Yours, Linus Walleij
