Plea for help with GPIO pin naming

[Johannes Truschnigg]

Dear list,

in my ongoing hobbyist quest to port OpenBMC to the Gigabyte MC12-LE0, I face
some challenges that leave me scratching my head - hence me posting here.
Today's questions concern GPIO line names and x86-power-control aka
/usr/bin/power-control.

I've been reverse-engineering my board's GPIO pins for a while now, and once I
figure out what a particular pin is (probably) actually good and used for, I
most of the time have a hard time identifying the proper name/label for that
particular pin.

I don't have a background in electronics, much less PCB design, but I guess
most line names in OpenBMC's DTS files are lifted verbatim from board
schematics, which I do not have for my board. That, as well as the sprawl of
pin labels and names used between existing platforms and boards, makes it very
hard for me to infer the meaning of most pins defined for supported OpenBMC
machines.

My research led me to a design document from 2020 with the promising title
"Device Tree GPIO Naming in OpenBMC"[0], but since I can't seem to find the
proposed names in any of OpenBMC meta layers, I guess it always remained a
proposal, without proper uptake in the real world? This hunch of mine is
somewhat exacerbated by the fact that the x86-power-control package assumes
very different pin names in its default example config file[1] (although a
GitHub issue[2] exists that makes it somewhat plausible that might not be 100%
deliberate)...

What I'd like to have is a solid guideline on how to interpret existing boards'
DTS pin names (unfortunately, I don't know what either of SIO_POWER_GOOD or
PS_PWROK exactly describe, or what the difference between the concepts the two
strings of characters map to in the physical world might be), assuming little
prior knowledge of these dark arts. Is there material on the web that isn't
buried under mountains of mainboard-designer-specific NDAs that could help me
with making sense of all the jargon I don't know? I'd be very thankful if
someone could point me a way!

Thanks very much for reading this far! :)

[0]: https://github.com/openbmc/docs/blob/master/designs/device-tree-gpio-naming.md
[1]: https://github.com/openbmc/x86-power-control/blob/master/config/power-config-host0.json
[2]: https://github.com/openbmc/x86-power-control/issues/4

-- 
with best regards:
- Johannes Truschnigg ( johannes at truschnigg.info )

www:   https://johannes.truschnigg.info/
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