Re: [PATCH V15 6/9] mfd: pm8008: Use i2c_new_dummy_device() API

From: Lee Jones
Date: Thu Sep 29 2022 - 14:01:54 EST


On Wed, 28 Sep 2022, Stephen Boyd wrote:

> Quoting Lee Jones (2022-09-28 03:20:30)
> > Wouldn't it make more sense to simply separate the instantiation of
> > the 2 I2C devices? Similar to what you suggested [0] in v9. That way
> > they can handle their own resources and we can avoid all of the I2C
> > dummy / shared Regmap passing faff.
> >
> > [0] https://lore.kernel.org/all/CAE-0n53G-atsuwqcgNvi3nvWyiO3P=pSj5zDUMYj0ELVYJE54Q@xxxxxxxxxxxxxx/
> >
>
> You can continue reading the thread[1]. My understanding is it's one
> chip that responds on two i2c addresses, thus we don't describe that as
> two i2c device nodes in DT. Instead we describe one node and use the
> dummy API to make the second i2c device.
>
> [1] https://lore.kernel.org/all/Yk3NkNK3e+fgj4eG@xxxxxxxxxxxxx/

As Mark says, it's probably 2 separate dies that have been encased in
the same IC and are otherwise unconnected. Not sure I understand the
comment about not requiring another 'struct device'. It will still
require that whether it's a platform device or an I2C device, right?

--
Lee Jones [李琼斯]