RE: [PATCH 4/9] regulator: bd71837: Devicetree bindings for BD71837 regulators

[Vaittinen, Matti]

Hello Mark,

First of all, thank you for taking your time to check the patches. I do
appreciate it. I find reading patches hard myself.

> From: Mark Brown [broonie@xxxxxxxxxx]
> Sent: Thursday, May 24, 2018 5:01 PM
> 
> > On Thu, May 24, 2018 at 08:57:52AM +0300, Matti Vaittinen wrote:
>
> > +Required properties:
> > + - compatible: should be "rohm,bd71837-pmic".
> > + - regulator-name: should be "buck1", ..., "buck8" and "ldo1", ..., "ldo7"
>
> The MFD is for a single device, there should be no need for compatibles
> on subfunctions.

I will check this. I must admit I am not sure what is the de-facto mechanism
for assigning the correct device-tree nodes to sub devices if compatibles
are not used? I think I saw device-tree node name being used for regulators
but how is it done for example with clk? I would be grateful if anyone could
point me to right direction with this.

Also, another thing I was wondering is how supply regulators should be
handled? In this case the LDO5 is supplied by BUCK6 and LDO6 by
BUCK7. 

>From generic regulator bindings
/Documentation/devicetree/bindings/regulator/regulator.txt
I found statement:

> - <name>-supply: phandle to the parent supply/regulator node

and

> Regulator Consumers:
> Consumer nodes can reference one or more of its supplies/
> regulators using the below bindings.
>
> - <name>-supply: phandle to the regulator node
>
> These are the same bindings that a regulator in the above
> example used to reference its own supply, in which case
> ts just seen as a special case of a regulator being a
> consumer itself.

but I did not find handling for the supply properties from regulator core.
Thus I ended up hard coding the supply relation in driver. This means
that buck6 name must be fixed.

Br,
    Matti Vaittinen