Re: [PATCH v3 8/8] dt-bindings: Add rt5033 mfd, regulator and charger

[Jakob Hauser]

Hi Krzysztof,

On 01.05.23 19:35, Jakob Hauser wrote:
> On 01.05.23 09:21, Krzysztof Kozlowski wrote:
> > On 28/04/2023 01:30, Jakob Hauser wrote:
> > > Add device tree binding documentation for rt5033 multifunction 
> > > device, voltage
> > > regulator and battery charger.
> > >
> > > Cc: Beomho Seo <beomho.seo@xxxxxxxxxxx>
> > > Cc: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
> > > Signed-off-by: Jakob Hauser <jahau@xxxxxxxxxxxxxx>
> >
> >
> > (...)
> >
> > > +
> > > +required:
> > > +  - monitored-battery
> > > +
> > > +additionalProperties: false
> > > +
> > > +examples:
> > > +  - |
> > > +    charger {
> > > +        compatible = "richtek,rt5033-charger";
> > > +        monitored-battery = <&battery>;
> > > +        extcon = <&muic>;
> >
> >
> > Everything up to here looked ok, but extcon is not a hardware property.
> > Please do not mix adding missing bindings for existing device with
> > adding new properties. You should use connector for the USB port.

...

> And how to set up the rt5033-charger to retrieve the information of the 
> extcon/muic driver in that case?

...

To add more context:
According to my understanding, the extcon subsystem provides three ways 
to get an extcon device [3]:
- by name
- by devicetree node
- by phandle

For rt5033-charger, the extcon device name can be different depending on 
the consumer device. For the node I wouldn't know how to get from the 
charger/mfd node to the extcon node, I don't see a direct relation in 
case of rt5033-charger (it's no parent node or something like that). 
Therefore I chose the third option: phandle.

In the rt5033-charger driver, the location of the 
extcon_get_edev_by_phandle() call is shown in link [4], it gets added in 
patch 6.

[3] 
https://github.com/torvalds/linux/blob/v6.3/include/linux/extcon.h#L223-L229
[4] 
https://github.com/Jakko3/linux/blob/rt5033-charger_v3/drivers/power/supply/rt5033_charger.c#L677

Kind regards,
Jakob