Re: Adding I2C devices to the SMBus (PIIX4) via the ACPI SSDT overlay method

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Fri, Nov 08, 2024 at 10:27:08AM +0100, Florian Eckert wrote:
> On 2024-11-08 09:46, Andy Shevchenko wrote:
> > +Cc: Florian (as this indeed rang a bell to me)
> > 
> > https://lore.kernel.org/all/d84fb798722762862a7fb08f1e343b6a@dev.tdt.de/
> 
> The message was forwarded by Andy because I had a similar problem with my
> APU3 [1]
> from PC-engine [2], which is also using the PIIX4 for I2C (SMBUS).
> 
> > > Maybe I need to modify ACPI code somehow to create these
> > > 'physical_nodesX' folders for the relevant i2c-7/8/9 buses?
> 
> I don't know if that helps, but with the following SSDT overlay I managed
> to get the driver to feel responsible for the mcp23017 via the I2C (SMBUS)
> of the APU3. The mcp23017 is used on my APU3 to add additional LEDs to
> '/sys/class/leds'.

Thanks for prompt response!
Can you, folks, elaborate and update the in-kernel documentation [1]
by adding a section to it for the above topic, so next time I have got
a Q like this I can point to there?

[1]: Documentation/i2c/busses/i2c-piix4.rst

-- 
With Best Regards,
Andy Shevchenko