Re: Wrong GPIO mapping for Alder Lake U?

[Andy Shevchenko <andy.shevchenko@xxxxxxxxx>]

On Wed, Jun 19, 2024 at 2:31 PM Andri Yngvason <andri@xxxxxxxxxxx> wrote:
>
> Hi,
>
> I'm trying to use GPIO on an Alder Lake U processor with a ACPI device
> id INTC1055.
>
> Commit 0e793a4e283487378e9a5b7db37bc1781bc72fd7 added this device id
> to drivers/pinctrl/intel/pinctrl-tigerlake.c and states that Alder
> Lake P uses the same PCH. However, I am having a very hard time
> matching pin names from the schematics that I was given with names in
> the source file or with names from the dataheet for P-PCH 500.
>
> Based on Intel's web page [1], I have been able to ascertain that
> Alder Lake U has P-PCH 600, for which the pin names in the datasheet
> do indeed match what I see on my schematics.
>
> Is it correct to conclude that this is simply wrong as is?

TL:DR; Do you have any issues in practice with any of the GPIOs on
this board? If not, then there are no problems with the code :-)

The Linux ideology of device drivers is to avoid code duplication.
Since we have the same IP, we reuse the driver, however in the
original one the pin names were used for different PCH. So, if the
issue is only with the naming, you need to find a mapping between
schematics and the standard form of GPP_X_nn (where 'X' is a group
name, and 'nn' is the relative number of the pin) that is used in all
of those chips. You may follow the comments in the code which starts
the groups of pins followed by the pin names and numbers. As long as
you know the basic (or "normalized") form of the pin you may easily
associate it with Linux pin number via the source of the driver.

> [1]: https://edc.intel.com/content/www/us/en/design/ipla/software-development-platforms/client/platforms/alder-lake-desktop/12th-generation-intel-core-processors-datasheet-volume-1-of-2/



-- 
With Best Regards,
Andy Shevchenko