On 4/26/22 9:21 AM, Harald Geyer wrote: >>>> PD, PE and PL have dedicated regulators, that can be matched via the >>>> 'regulator-name' property. I didn't want to specify the same >>>> information in two places. >>> >>> "regulator-name" is only a label, while phandle is actual regulator reference >>> that can be used by the driver. > > That is clearly not the whole story, as the driver find's the supply > for the PD bank just fine. And this even isn't an always-on regulator. > > See the attached dmesg logs. You are right, the Linux function regulator_dev_lookup() falls back to matching by regulator name if no property exists in the devicetree. But again this is a Linux-ism that we would rather not rely on. >>>> For the PF supply, I couldn't find any connection information in the >>>> board schematic. I could have added a dummy regulator. But since there >>>> is only one warning about pf-supply during driver initialization and >>>> not the dozens of warnings I see about PC and PG, I figured, I'd rather >>>> not add information of dubious use or qualiy. >>> >>> You mean PE right? There is no PF supply on A64. > > I meant PF, but you are right, that this doesn't have a supply on A64 > at all. However the driver doesn't seem to know this: It emits a > warning about missing PF supply at startup. > >>> Anyway, if it's not on schematic, it can be assumed unconnected and thus >>> you shouldn't define that property. Messages like "using dummy regulator" >>> are fine in such cases . >> >> All of the ports without a separate VCC-Px input are powered by >> VCC-IO, which in this case is supplied from DCDC1. > > So should I add "vcc-pf-supply = <®_dcdc1>;" even though the chip > actually doesn't support a dedicated vcc-pf-supply or should I just > ignore this? Yes, you should add this property. The supplies are a bit more abstract than you are expecting. Each of these pin banks (unless it is totally unused) has to get power from _somewhere_, and that "somewhere" is the supply that should be referenced. There is no need for the supply to be a dedicated pin, or for the supply name to match any pin or regulator name. For example, the LRADC needs a reference voltage for its comparator, so it has a "vref-supply" property. But there is no "VREF" pin. The LRADC's reference voltage is one of several things internally connected to the SoC's "AVCC" pin. So here, vcc-pf-supply just means abstractly "the voltage supply for Port F". The fact that sometimes there also happens to be a pin named VCC-Px is the result of not coming up with a second name for something that has a perfectly good name already. Regards, Samuel
