RE: [PATCH v4 1/2] regulator: act8945a: add regulator driver for ACT8945A

[Yang, Wenyou]

Hi Peter,

> -----Original Message-----
> From: Peter Korsgaard [mailto:jacmet@xxxxxxxxx] On Behalf Of Peter Korsgaard
> Sent: 2016年2月3日 1:42
> To: Mark Brown <broonie@xxxxxxxxxx>
> Cc: Yang, Wenyou <Wenyou.Yang@xxxxxxxxx>; Liam Girdwood
> <lgirdwood@xxxxxxxxx>; Rob Herring <robh+dt@xxxxxxxxxx>; Pawel Moll
> <pawel.moll@xxxxxxx>; Ian Campbell <ijc+devicetree@xxxxxxxxxxxxxx>; Kumar
> Gala <galak@xxxxxxxxxxxxxx>; Krzysztof Kozlowski
> <k.kozlowski@xxxxxxxxxxx>; Javier Martinez Canillas <javier@xxxxxxxxxxxx>;
> Lee Jones <lee.jones@xxxxxxxxxx>; Peter Korsgaard <jacmet@xxxxxxxxx>; Ferre,
> Nicolas <Nicolas.FERRE@xxxxxxxxx>; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v4 1/2] regulator: act8945a: add regulator driver for
> ACT8945A
> 
> >>>>> "Mark" == Mark Brown <broonie@xxxxxxxxxx> writes:
> 
>  > On Fri, Jan 29, 2016 at 01:20:08AM +0000, Yang, Wenyou wrote:
>  >> > > +static const struct of_device_id act8945a_pmic_of_match[] = {
>  >> > > +	{ .compatible = "active-semi,act8945a-regulator" },
>  >> > > +	{ },
>  >> > > +};
>  >> > > +MODULE_DEVICE_TABLE(of, act8945a_pmic_of_match);
> 
>  >> > This seems mostly OK but why do we have a compatible string here -
> shouldn't  >> > the MFD be able to instantiate the regulator function without
> needing this?
> 
>  >> Because I got feedback from Javier for the act8945a-charger patches of this
> MFD series,  >> He said missing the OF match table will cause the module
> autoloading broken.
> 
>  >> http://lists.infradead.org/pipermail/linux-arm-kernel/2016-January/398113.html
> 
>  >> What do you think about it?
> 
>  > If then device is not being loaded from the DT (and it shouldn't be, the  > device
> looks like it should be instantiated directly by the MFD as it  > can't exist
> separately to that MFD) an OF table will do nothing.
> 
> To add to the confusion, the regulator part of the chip is actually identical to
> act8865, so it could use the existing regulator driver / compatible, except that it
> binds to the platform bus instead of i2c.

Thank you for your opinion.

But I think It is better to make it a separate driver, the driver is simpler. 

> 
> --
> Bye, Peter Korsgaard


Best Regards,
Wenyou Yang