Re: [PATCH] mfd: devicetree: bindings: Add Qualcomm RPM regulator subnodes

From: Bjorn Andersson
Date: Tue Feb 17 2015 - 16:48:35 EST


On Fri, Feb 13, 2015 at 2:13 PM, Andy Gross <agross@xxxxxxxxxxxxxx> wrote:
> On Thu, Jan 29, 2015 at 05:51:06PM -0800, Bjorn Andersson wrote:
>> Add the regulator subnodes to the Qualcomm RPM MFD device tree bindings.
>>
>> Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxx>
>> ---
>
>> #include <dt-bindings/mfd/qcom-rpm.h>
>> @@ -66,5 +237,18 @@ frequencies.
>>
>> #address-cells = <1>;
>> #size-cells = <0>;
>> +
>> + pm8921_smps1: pm8921-smps1 {
>> + compatible = "qcom,rpm-pm8921-smps";
>> + reg = <QCOM_RPM_PM8921_SMPS1>;
>> +
>> + regulator-min-microvolt = <1225000>;
>> + regulator-max-microvolt = <1225000>;
>> + regulator-always-on;
>> +
>> + bias-pull-down;
>> +
>> + qcom,switch-mode-frequency = <3200000>;
>> + };
>> };
>
> My only comment here is that most (all but one) of the other mfd regulator
> devices use regulators {}. Still wonder if that's what we should do.
>

Looking at the existing mfds they all have a list in the code of the
regulators supported on a certain mfd. Through the use of
regulator_desc.{of_match,regulators_node} these regulators are
populated with properties from of_nodes matched by name (of_match)
under the specified node (regulators_node).
But as we've discussed in other cases it's not desirable to maintain
these lists for the various variants of Qualcomm platforms, so I did
choose to go with "standalone" platform devices - with matching
through compatible and all.

But that's all implementation, looking at the binding itself a
regulator {} (clocks{} and msm_bus{}) would serve as a sort of
grouping of children based on type. Except for the implications this
has on the implementation I don't see much benefit of this (and in our
case the implementation would suffer from the extra grouping).


Let me know what you think, I based these ideas on just reading the
existing code and bindings, and might very well have missed something.

> Otherwise,
>
> Reviewed-by: Andy Gross <agross@xxxxxxxxxxxxxx>
>

Thanks

Regards,
Bjorn
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