Re: [PATCH v2] gpio: vortex: add new GPIO device driver

[Marcos Del Sol Vives <marcos@orca.pet>]

El 11/07/2025 a las 12:19, Bartosz Golaszewski escribió:
> This looks better but I admit I'm not an expert in x86 platforms so
> I'll allow myself to Cc Andy. Is this how it's typically done in x86?
> Is this module visible in ACPI in any way that would allow us to
> leverage the platform device core? Or do we need to try to register
> the device unconditionally on all Vortex platforms?

Again I want to point out I am not an expert by any means. This is my first
kernel driver and I am writting it as a hobbyst, not as a company employee.

Regarding ACPI: I have just now decompiled the DSDT for the Vortex86DX3
machine and I do not see any Device() claiming ownership of 0x78 or 0x98,
or mentioning GPIO at all:

root@vdx3:/home/marcos/acpi# ls -l *.dsl
-rw-r--r-- 1 root root   3459 Jul 11 16:05 APIC.dsl
-rw-r--r-- 1 root root 196800 Jul 11 16:05 DSDT.dsl
-rw-r--r-- 1 root root   9211 Jul 11 16:22 FACP.dsl
-rw-r--r-- 1 root root   1364 Jul 11 16:22 FACS.dsl
-rw-r--r-- 1 root root   1552 Jul 11 16:23 MSDM.dsl
-rw-r--r-- 1 root root      0 Jul 11 16:07 OEMB.dsl
-rw-r--r-- 1 root root   3957 Jul 11 16:07 SLIC.dsl
root@vdx3:/home/marcos/acpi# grep -Ri gpio *.dsl
root@vdx3:/home/marcos/acpi# grep -Ri 0x0078 *.dsl

Manually skimming through DSDT does not yield anything useful either.

This kinda confirms what the company told me: the machine does not properly
support ACPI, it has a set of fake tables enough to convince Windows 7 into
booting.

The Vortex86MX board does not even have those, and has no ACPI tables
whatsoever.

And regarding something I forgot to answer on the previous email about the
future of these machines: the Vortex86MX is a i586 processor, and this
Vortex86DX3 is a dual-core i686 processor with SSE1 support that I myself
bought brand new from the manufacturer, indicating they are still making
and supporting them.

The company is seemingly launching next year also a Vortex86EX3 with proper
i686 and SSE2 support, I guess because Intel's patents have finally expired.

So I do not think removing i486 support is gonna be an issue except for
very ancient processors that the company is not making anymore anyway.

Thanks,
Marcos