Re: [PATCH] docs: i2c: piix4: Add ACPI section

[Andy Shevchenko]

On Mon, Nov 11, 2024 at 02:52:57PM +0200, Andy Shevchenko wrote:
> On Mon, Nov 11, 2024 at 02:56:52PM +0300, Konstantin Aladyshev wrote:
> > Provide information how to reference I2C busses created by the PIIX4
> > chip driver from the ACPI code.

...

> > +Therefore if you want to access one of these busses in the ACPI code, you need to
> > +declare port subdevices inside the PIIX device::
> > +
> > +    Scope (\_SB_.PCI0.SMBS)
> > +    {
> > +        Name (_ADR, 0x00140000)
> > +
> > +        Device (SMB0) {
> > +            Name (_ADR, 0)
> > +        }
> > +        Device (SMB1) {
> > +            Name (_ADR, 1)
> > +        }
> > +        Device (SMB2) {
> > +            Name (_ADR, 2)
> > +        }
> > +    }
> 
> You need to elaborate that some of this data may be already present in the BIOS
> DSDT (you give your example as it seems most common so far) and hence requires
> an additional per-port addresses. With that you should add a note that this
> will require to load SSDT quite in advance to make sure that the driver will
> see these changes before its ->probe().
> 
> ...
> 
> The rest is LGTM.

Also Cc new version to Andi Shyti who is I2C host driver maintainer.
It's probably he who is going to apply the change.

-- 
With Best Regards,
Andy Shevchenko