On Tue, Jun 21, 2022 at 02:09:14PM +0300, Andy Shevchenko wrote:

On Mon, Jun 20, 2022 at 09:47:31PM +0200, Andrew Lunn wrote:

...

quoted

quoted

+        Name (_CRS, ResourceTemplate ()
+        {
+            Memory32Fixed (ReadWrite,
+                0xf212a200,
+                0x00000010,

What do these magic numbers mean?

Address + Length, it's all described in the ACPI specification.

The address+plus length of what? This device is on an MDIO bus. As
such, there is no memory! It probably makes sense to somebody who
knows ACPI, but to me i have no idea what it means.

Or if you asked
why the values there are the particular numbers? I guess it's fined to have
anything sane in the example. OTOH a comment may be added.

quoted

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+                )
+        })

...

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+        Device (SWI0)
+        {
+            Name (_HID, "MRVL0120")
+            Name (_UID, 0x00)
+            Name (_ADR, 0x4)
+            <...>
+        }

I guess it is not normal for ACPI, but could you add some comments
which explain this. In DT we have

    properties:
      reg:
        minimum: 0
        maximum: 31
        description:
          The ID number for the device.

which i guess what this _ADR property is, but it would be nice if it
actually described what it is supposed to mean. You have a lot of
undocumented properties here.

Btw, you are right, _ADR mustn't go together with _HID/_CID.

Does ACPI have anything like .yaml to describe the binding and tools
to validate it?

   Andrew