Re: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices

[Hans de Goede <hansg@kernel.org>]

Hi,

On 2-Oct-25 11:18 AM, Sakari Ailus wrote:
> Hi Hans,
> 
> On Thu, Oct 02, 2025 at 10:56:47AM +0200, Hans de Goede wrote:
>> Hi,

...

>>>> INTC10D2 is apparently already claimed by the LJCA I²C driver. Do you have
>>>> an actual system that uses USBIO and this HID?
>>>
>>> Actually it looks like i2c-ljca.c shouldn't list this HID. The same
>>> probably goes for all 10CF--10D3.
>>
>> I would not be so sure of this, there are at least some Dell systems
>> which use a combination of ljca and Meteor Lake and I believe these
>> do use the "INTC10D2" HID with LJCA for the I2C part and the same
>> goes for the GPIO / SPI parts.. One example of such a system is
>> the Dell Precision 5490.
> 
> LJCA on MTL is supposed to be 1008. Do you have the *SDT so we could verify
> this?

I just checked this in a ssh session to the Dell Precision 5490:

hans@prdel:~$ cd /sys/bus/auxiliary/devices/
hans@prdel:/sys/bus/auxiliary/devices$ ls
intel_ipu6.isys.40      intel_vsec.telemetry.2  soundwire_intel.link.2  usb_ljca.ljca-i2c.1
intel_ipu6.psys.40      snd_sof.hda-probes.0    soundwire_intel.link.3  usb_ljca.ljca-spi.0
intel_vsec.telemetry.0  soundwire_intel.link.0  usb_ljca.ljca-gpio.0
intel_vsec.telemetry.1  soundwire_intel.link.1  usb_ljca.ljca-i2c.0
hans@prdel:/sys/bus/auxiliary/devices$ cat usb_ljca.ljca-*/firmware_node/hid 
INTC10D1
INTC10D2
INTC10D2
INTC10D3

So as you can see this really is using the INTC10D* HIDs and these
are thus duplicate between the LJCA and USBIO IO-expanders.

Note this does not really cause problems since we have the USB driver
binding by USB VID:PID first and only then the code looks for
the ACPI HIDs for the GPIO/I2C/SPI children so at this point we are
already in LJCA resp. USBIO specific code-paths.

I've also asked for an acpidump, do you still want that once I receive it ?

Regards,

Hans