[PATCH v2 1/2] dt-bindings: samsung,mipi-dsim: Add 'lane-polarities'

[Fabio Estevam]

Hi Rob,

On 12/04/2023 11:43, Rob Herring wrote:

> No, this should be video-interfaces.yaml since you use properties from
> it.

Ok, will change it.

> 
>> +            unevaluatedProperties: false
>> +
>> +            properties:
>> +              data-lanes:
>> +                oneOf:
>> +                  - minItems: 1
>> +                    maxItems: 4
>> +                    uniqueItems: true
>> +                    items:
>> +                      enum: [ 1, 2, 3, 4 ]
> 
> The h/w really supports any combination of lanes to be used?

The MIPI DSIM IP supports the usage of 1, 2, 3, or 4 data lanes.

The following cases are possible:

data-lanes = <1>;
data-lanes = <1 2>;
data-lanes = <1 2 3>;
data-lanes = <1 2 3 4>;

Lane reordering is not supported.

> 
>> +                    description:
>> +                      See ../../media/video-interfaces.yaml for 
>> details.
>> +
>> +              lane-polarities:
>> +                minItems: 1
>> +                maxItems: 5
>> +                items:
>> +                  enum: [ 0, 1 ]
>> +                description:
>> +                  See ../../media/video-interfaces.yaml for details.
>> +                  The Samsung MIPI DSI IP requires that all the data 
>> lanes have
>> +                  the same polarity.
> 
> Sounds like a constraint:
> 
> oneOf:
>   - items:
>       const: 0
>   - items:
>       const: 1

Imagine a board that has 4 data lanes and only the clock lane is 
inverted.

The representation is (the first entry is the clock lane, followed by 
the 4 data lanes):

lane-polarities = <1 0 0 0 0>;

If the board has no inversion on the clock lane, and has the data lanes 
inverted:

lane-polarities = <0 1 1 1 1>;

Should I keep the data-lanes and lane-polarities description as in this 
patch?

Please advise.

Thanks,

Fabio Estevam