Hi On Fri, Mar 16, 2018 at 6:09 PM, David Collins <collinsd@xxxxxxxxxxxxxx> wrote: > Introduce bindings for RPMh regulator devices found on some > Qualcomm Technlogies, Inc. SoCs. These devices allow a given > processor within the SoC to make PMIC regulator requests which > are aggregated within the RPMh hardware block along with requests > from other processors in the SoC to determine the final PMIC > regulator hardware state. > > Signed-off-by: David Collins <collinsd@xxxxxxxxxxxxxx> > --- > .../bindings/regulator/qcom,rpmh-regulator.txt | 246 +++++++++++++++++++++ > 1 file changed, 246 insertions(+) > create mode 100644 Documentation/devicetree/bindings/regulator/qcom,rpmh-regulator.txt > > diff --git a/Documentation/devicetree/bindings/regulator/qcom,rpmh-regulator.txt b/Documentation/devicetree/bindings/regulator/qcom,rpmh-regulator.txt > new file mode 100644 > index 0000000..2d86306 > --- /dev/null > +++ b/Documentation/devicetree/bindings/regulator/qcom,rpmh-regulator.txt > @@ -0,0 +1,246 @@ > +Qualcomm Technologies, Inc. RPMh Regulators > + > +rpmh-regulator devices support PMIC regulator management via the VRM and XOB > +RPMh accelerators. The APPS processor communicates with these hardware blocks > +via an RSC using command packets. The VRM allows changing four parameters for a > +given regulator: enable state, output voltage, operating mode, and minimum > +headroom voltage. The XOB allows changing only a single parameter for a given > +regulator: its enable state. Somewhere in here can you give some context of what VRM and XOB stand for. From the other patch desc it's "voltage regulator manager (VRM) and oscillator buffer (XOB)", but nice to sprinkle that around the first time it's used in documents. ...and, ummmmm, what's an oscillator buffer? Is this really a regulator? It sounds a lot more like a clock enable knob. Are you sure this shouldn't be exposed through the common clock framework? Many other PMICs expose oscillator clocks through CCF. MAX77686 comes to mind. > +- regulator-name > + Usage: optional > + Value type: <string> > + Definition: Specifies the name for this RPMh regulator. If not > + specified, then the regulator's name is equal to its subnode > + name. Probably don't need to include "regulator-name" since you say below "Other properties defined in regulator.txt may also be used" and this isn't anything special for your regulator. > +- regulator-min-microvolt > + Usage: required > + Value type: <u32> > + Definition: For VRM resources, this is the minimum supported voltage in > + microvolts. For XOB resources, this is the fixed output > + voltage. > + > +- regulator-max-microvolt > + Usage: required > + Value type: <u32> > + Definition: For VRM resources, this is the maximum supported voltage in > + microvolts. For XOB resources, this is the fixed output > + voltage. regulator-min-microvolt / regulator-max-microvolt are really required? What happens if you leave them off? In general the regulator framework supports this concept--it just lets you enable/disable without changing voltage. > +- qcom,regulator-initial-voltage > + Usage: optional; VRM regulators only > + Value type: <u32> > + Definition: Specifies the initial voltage in microvolts to request for a > + VRM regulator. Supported values are 0 to 8191000. The "supported values" here is a strange statement to make. Not all regulators will support all those voltages, right? Do you really need to list this here? > +- regulator-initial-mode > + Usage: optional; VRM regulators only > + Value type: <u32> > + Definition: Specifies the initial mode to request for a VRM regulator. > + Supported values are RPMH_REGULATOR_MODE_* which are defined > + in [1] (i.e. 0 to 4). Explicitly state whether this is allowed even if "regulator-allow-set-load" is not set. > +- regulator-allow-set-load > + Usage: optional > + Value type: <empty> > + Definition: Boolean flag indicating that the the mode of this regulator > + may be configured at runtime based upon consumer load needs. > + > +- qcom,allowed-modes It would be up to Mark Brown, but my guess is that he will say "please add this to the core". The regulator core already has the concept of modes and you're already using the standard core concepts in most places. Get rid of the special case code in your driver and add this to the core. > + Usage: required if regulator-allow-set-load is specified; > + VRM regulators only > + Value type: <prop-encoded-array> > + Definition: A list of integers specifying the PMIC regulator modes which > + can be configured at runtime based upon consumer load needs. > + Supported values are RPMH_REGULATOR_MODE_* which are defined > + in [1] (i.e. 0 to 4). Elements must be specified in order > + from lowest to highest value. As far as I can tell this sorting constraint should be removed. Really the constraints should be: * qcom,mode-threshold-currents should be sorted from lowest to highest * qcom,allowed-modes must match qcom,mode-threshold-currents Sure, today it happens that the numbers are always lower for lower currents, but it doesn't seem like something you'd have to encode into the dt. > +- qcom,headroom-voltage > + Usage: optional; VRM regulators only > + Value type: <u32> > + Definition: Specifies the headroom voltage in microvolts to request for > + a VRM regulator. RPMh hardware automatically ensures that > + the parent of this regulator outputs a voltage high enough > + to satisfy the requested headroom. Supported values are > + 0 to 511000. Is this just "regulator-microvolt-offset", but supported in hardware? > +- qcom,rpmh-resource-type > + Usage: optional > + Value type: <string> > + Definition: RPMh accelerator type for this regulator. If not specified, > + then the default type associated with this regulator will be > + used. Supported values: "vrm" or "xob". I still don't have the big picture I guess, but it seems weird that you can override this. You're saying that someone might stick an oscillator buffer the place of something that's normally a regulator? ...or a regulator in the place of something that's usually an oscillator buffer? When would you use this? -Doug -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
