dt_binding_check report false alarm?

[William Zhang]

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Hi Conor,

On 05/25/2023 06:23 AM, Conor Dooley wrote:
> Hey William,
> 
> On Wed, May 24, 2023 at 10:02:41PM -0700, William Zhang wrote:
>> Hi,
>>
>> It seems dt_binding_check reports a false error when run on this
>> modified yaml. I picked this simple file just to demostrate this issue.
>> Basically I made the interrupts and interrupt-names as optional
>> properties. But when there are two interrupts present, then
>> interrupt-names are required.  However in the example, I don't define
>> interrupts and interrupt-name at all, the dt binding check reports error
>> that interrupt-names are required:
> 
> Rob and Krzysztof would know more than me, but since they're not
> around...
> 
>> diff --git a/Documentation/devicetree/bindings/crypto/fsl-imx-scc.yaml b/Documentation/devicetree/bindings/crypto/fsl-imx-scc.yaml
>> index 563a31605d2b..c37a3a64a78c 100644
>> --- a/Documentation/devicetree/bindings/crypto/fsl-imx-scc.yaml
>> +++ b/Documentation/devicetree/bindings/crypto/fsl-imx-scc.yaml
>> @@ -32,11 +32,18 @@ properties:
>>     clock-names:
>>       const: ipg
>>   
>> +allOf:
>> +  - if:
>> +      properties:
>> +        interrupts:
>> +          minItems: 2
> 
> ...I don't think you can actually do this and "minItems: 2" will always
> evaluate to true because it is an assignment. Don't hold me to that
> though! The standard pattern here is to do:
> allOf:
>    - if:
>        properties:
>          compatible:
>            contains:
>              const: foo
>      then:
>        required:
>          - interrupt-names
> 
> Cheers,
> Conor.
> 
Our device can use one or two interrupt, or choose to not use interrupt 
at all(polling mode). Interrupt names is only required when there are 
two interrupts(so the driver code can tell which is which).  So I will 
need to check if it contains two interrupts. My check does work if I 
have two interrupt but don't have interrupt name, the check catches the 
error.  If I have one interrupt without interrupt name, the check pass. 
Only when I does not have interrupt and interrupt name,  it falsely 
report error.  Looks to me that it does not treat minItem = 0 case 
properly.


>> +    then:
>> +      required:
>> +        - interrupt-names
>> +
>>   required:
>>     - compatible
>>     - reg
>> -  - interrupts
>> -  - interrupt-names
>>     - clocks
>>     - clock-names
>>   
>> @@ -49,6 +56,4 @@ examples:
>>           reg = <0x53fac000 0x4000>;
>>           clocks = <&clks 111>;
>>           clock-names = "ipg";
>> -        interrupts = <49>, <50>;
>> -        interrupt-names = "scm", "smn";
>>       };
>> -- 
>> 2.34.1
>>
> 
> 
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