Re: [PATCH v4 1/2] mfd: rohm-bd71828: Use software nodes for gpio-keys

[Matti Vaittinen]

On 29/04/2026 08:53, Matti Vaittinen wrote:
> Hi Dee Ho,
>
> Thanks a ton Dmitry! This is looking very good to me now. I only have 
> one question below.
>
> On 28/04/2026 07:13, Dmitry Torokhov wrote:
> > Refactor the rohm-bd71828 MFD driver to use software nodes for
> > instantiating the gpio-keys child device, replacing the old
> > platform_data mechanism.
> >
> > The power key's properties are now defined using software nodes and
> > property entries. The IRQ is passed as a resource attached to the
> > platform device.
> >
> > This will allow dropping support for using platform data for configuring
> > gpio-keys in the future.
> >
> > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> > ---
> >   drivers/mfd/rohm-bd71828.c | 122 ++++++++++++++++++++++++++++++++ 
> > +------------
> >   1 file changed, 90 insertions(+), 32 deletions(-)
> >
> > diff --git a/drivers/mfd/rohm-bd71828.c b/drivers/mfd/rohm-bd71828.c
> > index a79f354bf5cb..a8bdb9c955a4 100644
> > --- a/drivers/mfd/rohm-bd71828.c
> > +++ b/drivers/mfd/rohm-bd71828.c
> > +    /* Node corresponding to gpio-keys device itself */
> > +    nodes[0].name = devm_kasprintf(dev, GFP_KERNEL, "%s-power-key", 
> > dev_name(dev));
> > +    if (!nodes[0].name)
> > +        return -ENOMEM;
>
> Do we have any guidance/rules for naming the swnodes similar to 
> devicetree nodes? Do they need to be unique, and are they used for 
> anything?
>
> I am wondering if the dev_name() is needed or if we should have some 
> 'numbering'? I am not sure if the node names can be used for anything, 
> but in some cases adding IC-type to names will hurt the "generic 
> usability". On the other hand, if names need to be unique, then some 
> numbering might be needed (although, this is not critical for this 
> driver as it is very unlikely there is a system with more than one of 
> these PMICs).

After thinking 2 seconds more... I suppose the dev_name() guarantees the 
name is unique :) So, please forget my babblings about numbering.


--
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Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

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