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. Best regards, Krzysztof
