On Tue, Nov 03, 2026 at 03:21:45PM +0000, Roman Vivchar wrote: > On Tuesday, November 3rd, 2026 at 4:42 PM, Daniel Thompson > <[email protected]> wrote: > > > On Tue, Nov 03, 2026 at 02:34:02PM +0000, Roman Vivchar wrote: > > > Hi Daniel, > > > > > > On Tuesday, November 3rd, 2026 at 4:05 PM, Daniel Thompson > > > <[email protected]> wrote: > > > > On Mon, Nov 02, 2026 at 09:58:48PM +0200, Roman Vivchar via B4 Relay > > > > wrote: > > > > > + led-max-microamp: > > > > > + minimum: 5000 > > > > > + maximum: 29800 > > > > > + default: 20200 > > > > > + > > > > > + vin-supply: true > > > > > + > > > > > +required: > > > > > + - compatible > > > > > + - reg > > > > > + - vin-supply > > > > > > > > Why is vin-supply required? > > > > > > > > > > The chip cannot function without VIN power supply. Even if it's on the > > > always-on power rail on certain board, there's always a chance it might be > > > accidentally left disabled on the other. It's better to document supply in > > > the bindings as far as I understand. > > > > You haven't just documented the binding, you have also made the property > > mandatory by adding it to required. > > > > So what I am asking is why is this property listed as required. You > > didn't implement the driver in a way that makes the supply mandatory. > > Not sure I follow. > > In the driver I've used devm_regulator_get_enable(), rather than _optional(), > since my understanding is that the non-optional helper is a standard kernel > API for required supplies (with regulator core warning and fallback to dummy > regulator in case DT omits it).
That dummy fallback essentially makes it optional. On a board with an always-on supply then there is no need to include vin-supply in the DTB. The driver will work just fine without it. > Do you suggest dropping vin-supply from required: ? On my board it's connected > to an always-on supply, though I can't tell about others. I can proceed with > this if the DT maintainers are okay with that. Given your answers then, yes, vin-supply should not be in the required: list (e.g. we don't want DT validation to fail for a DT that does not include a vin-supply). Daniel.
