Question about "xxx,yyy" style property

[Kuninori Morimoto]

The Subject was "Re: [PATCH] ASoC: dt-bindings: simple-card: care missing address #address-cells"

Hi Rob

I'm trying to create v2 of simple-card patch,
And got issue which I can't solve by myself.

I think "xxx,yyy" (= which has "," at the property name)
needs special care, but it is very un-understandable...
Now, I'm give up.
So, can I ask you 2 things about Yaml Doc "xxx,yyy" type property ?

========================
1) reference own definitions from "xxx,yyy"
========================

I guess "xxx,yyy" naming property needs to has "description", right ?

But, it is OK if it references "/schemas/xxxx"

	--- OK ------
	xxx,yyy:
	  description: xxx
	  $ref: /schemas/types.yaml#/definitions/phandle-array
	-------------

but, will be error if it references own definitions

	--- NG ------
	xxx,yyy:
	  description: xxx
	  $ref: "#/definitions/mydef"
	-------------

This is the related error

	-- error(?) --
	xxx.yaml: properties:xxx,yyy:\
	  $ref: '#/definitions/mydef' does not match 'types.yaml#[/]{0,1}definitions/.*'
	--------------

# but, there is no problem if it was defined as "patternProperties"

Q. The "xxx,yyy" property can't references own definitions,
   or needs some magical extra settings ??

========================
2) phandle for "xxx,yyy"
========================

I noticed that it seems "xxx,yyy" property can't be referenced.
Here, "xxx,yyy" has "type: object" and "additionalProperties: false"
(below didn't happen if it doesn't have "additionalProperties: false")

If "xxx,yyy" has phandle, but not referenced,
This is not a problem.

	--- OK ---
	...
	foo = <&bar>;
	...
	xxx_yyy: xxx,yyy {
	  ...
	};
	--------------

But will be error if it is referenced.

	--- NG ---
	foo = <&xxx_yyy>;
	...
	xxx_yyy: xxx,yyy {
	  ...
	};
	------------

The error is

	-- error ---
	xxx.yaml: xxx.yyy: \
	Additional properties are not allowed ('phandle' was unexpected)
	------------

Q. The "xxx,yyy" needs magical settings to be referenced, or can't be ?