Re: [PATCH v4 2/8] dt-bindings: mmc: mmc-spi-slot: Change voltage-ranges to uint32-matrix

[Krzysztof Kozlowski <krzk@kernel.org>]

On 12/06/2024 16:36, Frank Li wrote:
> On Tue, Jun 11, 2024 at 02:23:11PM -0600, Rob Herring wrote:
>> On Tue, Jun 11, 2024 at 12:01:47PM -0400, Frank Li wrote:
>>> According to common mmc core, voltages-ranges should be matrix.
>>>
>>> Signed-off-by: Frank Li <Frank.Li@nxp.com>
>>>
>>> ---
>>> Not sure why it impact other mmc yaml's voltage-ranges.
>>
>> It's a quirk of the tools. When decoding properties, the tools only know 
>> all possible types. Types are global, not per binding. Sometimes it can 
>> be figured out, but cases like this cannot be.
>>
>>> ---
>>>  Documentation/devicetree/bindings/mmc/mmc-spi-slot.yaml | 17 ++++++++++-------
>>>  1 file changed, 10 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/mmc/mmc-spi-slot.yaml b/Documentation/devicetree/bindings/mmc/mmc-spi-slot.yaml
>>> index 36acc40c7d181..05815b837219d 100644
>>> --- a/Documentation/devicetree/bindings/mmc/mmc-spi-slot.yaml
>>> +++ b/Documentation/devicetree/bindings/mmc/mmc-spi-slot.yaml
>>> @@ -27,17 +27,20 @@ properties:
>>>      maxItems: 1
>>>  
>>>    voltage-ranges:
>>> -    $ref: /schemas/types.yaml#/definitions/uint32-array
>>> +    $ref: /schemas/types.yaml#/definitions/uint32-matrix
>>>      description: |
>>>        Two cells are required, first cell specifies minimum slot voltage (mV),
>>>        second cell specifies maximum slot voltage (mV).
>>>      items:
>>> -      - description: |
>>> -          value for minimum slot voltage in mV
>>> -        default: 3200
>>> -      - description: |
>>> -          value for maximum slot voltage in mV
>>> -        default: 3400
>>> +      items:
>>> +        - description: |
>>> +            value for minimum slot voltage in mV
>>> +          default: 3200
>>> +        - description: |
>>> +            value for maximum slot voltage in mV
>>> +          default: 3400
>>> +    minItems: 1
>>> +    maxItems: 8
>>
>> From what I remember, SPI mode doesn't support voltage changes. 
>> Switching to 1.8V came much later in the spec. So it should be 
>> 'maxItems: 1'. Or better yet, make the outer 'items' a list (of 1 
>> entry).
> 
> I don't understand "make the outer 'items' a list (of 1 entry)." Can guide
> me how to write it?

voltage-ranges:
  $ref: /schemas/types.yaml#/definitions/uint32-matrix
  items:
    - items:
        - descr:
        - descr:

Best regards,
Krzysztof