On 07/09/2022 22:49, Andrew Halaney wrote: > For RPMH regulators it doesn't make sense to indicate > regulator-allow-set-load without saying what modes you can switch to, > so be sure to indicate a dependency on regulator-allowed-modes. > > In general this is true for any regulators that are setting modes > instead of setting a load directly, for example RPMH regulators. A > counter example would be RPM based regulators, which set a load > change directly instead of a mode change. In the RPM case > regulator-allow-set-load alone is sufficient to describe the regulator > (the regulator can change its output current, here's the new load), > but in the RPMH case what valid operating modes exist must also be > stated to properly describe the regulator (the new load is this, what > is the optimum mode for this regulator with that load, let's change to > that mode now). > > With this in place devicetree validation can catch issues like this: > > /mnt/extrassd/git/linux-next/arch/arm64/boot/dts/qcom/sm8350-hdk.dtb: pm8350-rpmh-regulators: ldo5: 'regulator-allowed-modes' is a dependency of 'regulator-allow-set-load' > From schema: /mnt/extrassd/git/linux-next/Documentation/devicetree/bindings/regulator/qcom,rpmh-regulator.yaml > > Where the RPMH regulator hardware is described as being settable, but > there are no modes described to set it to! > > Suggested-by: Johan Hovold <johan+kernel@xxxxxxxxxx> > Reviewed-by: Johan Hovold <johan+kernel@xxxxxxxxxx> > Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx> > Signed-off-by: Andrew Halaney <ahalaney@xxxxxxxxxx> > --- > > v2: https://lore.kernel.org/linux-arm-msm/20220906201959.69920-1-ahalaney@xxxxxxxxxx/ > Changes since v2: > - Updated commit message to explain how this is a property of the > hardware, and why it only applies to certain regulators like RPMH > (Johan + Krzysztof recommendation) > - Added Johan + Douglas' R-B tags You posted before we finished discussion so let me paste it here: The bindings don't express it, but the regulator core explicitly asks for set_mode with set_load callbacks in drms_uA_update(), which depends on REGULATOR_CHANGE_DRMS (toggled with regulator-allow-set-load). drms_uA_update() later calls regulator_mode_constrain() which checks if mode changing is allowed (REGULATOR_CHANGE_MODE). Therefore based on current implementation and meaning of set-load/allowed-modes properties, I would say that this applies to all regulators. I don't think that RPMh is special here. Best regards, Krzysztof
