Re: [PATCH v2] drivers/mfd: simple-mfd-i2c: Add generic compatible

Lee Jones
2023-01-26T14:33:06Z

On Fri, 20 Jan 2023, Rob Herring wrote:

> On Thu, Jan 19, 2023 at 2:54 PM Lee Jones <lee@kernel.org> wrote:
> >
> > On Thu, 19 Jan 2023, Rob Herring wrote:
> >
> > > On Fri, Dec 02, 2022 at 06:32:26AM -0500, Jesse Taube wrote:
> > > > Some devices may want to use this driver without having a specific
> > > > compatible string. Add a generic compatible string to allow this.
> > >
> > > What devices need this?
> > >
> > > Is that no specific compatible string at all or just in the kernel?
> > > Because the former definitely goes against DT requirements. The latter
> > > enables the former without a schema.
> > >
> > > >
> > > > Signed-off-by: Jesse Taube <Mr.Bossman075@gmail.com>
> > > > ---
> > > > drivers/mfd/simple-mfd-i2c.c | 1 +
> > > > 1 file changed, 1 insertion(+)
> > > >
> > > > diff --git a/drivers/mfd/simple-mfd-i2c.c b/drivers/mfd/simple-mfd-i2c.c
> > > > index f4c8fc3ee463..0bda0dd9276e 100644
> > > > --- a/drivers/mfd/simple-mfd-i2c.c
> > > > +++ b/drivers/mfd/simple-mfd-i2c.c
> > > > @@ -73,6 +73,7 @@ static const struct simple_mfd_data silergy_sy7636a = {
> > > > };
> > > >
> > > > static const struct of_device_id simple_mfd_i2c_of_match[] = {
> > > > + { .compatible = "simple-mfd-i2c-generic" },
> > >
> > > Simple and generic? There is no such device. Anywhere.
> > >
> > > This is also not documented which is how I found it (make
> > > dt_compatible_check). But this should be reverted or dropped rather than
> > > documented IMO.
> >
> > I thought it would be better than having a huge list here.
>
> What indication is there that the list would be huge? We have 2 out of
> 137 MFD bindings. Usually if the MFD is simple, we'd make it a single
> node. It just needs to be clear what the conditions are for using it.
>
> > Devices should *also* be allocated a specific compatible string.
> >
> > $ git grep simple-mfd -- arch
>
> Why can't simple-mfd be used here?

Until this is clarified, agreed and documented, I'm dropping the patch.

--
Lee Jones [李琼斯]