Re: [PATCH v2 4/5] dt-bindings: dma: fsl-edma: add fsl,imx8ulp-edma compatible string

[Frank Li]

On Wed, Mar 06, 2024 at 02:40:23PM -0600, Rob Herring wrote:
> On Mon, Mar 4, 2024 at 5:31 PM Frank Li <Frank.li@xxxxxxx> wrote:
> >
> > On Mon, Mar 04, 2024 at 10:44:23AM -0600, Rob Herring wrote:
> > > On Thu, Feb 29, 2024 at 03:58:10PM -0500, Frank Li wrote:
> > > > From: Joy Zou <joy.zou@xxxxxxx>
> > > >
> > > > Introduce the compatible string 'fsl,imx8ulp-edma' to enable support for
> > > > the i.MX8ULP's eDMA, alongside adjusting the clock numbering. The i.MX8ULP
> > > > eDMA architecture features one clock for each DMA channel and an additional
> > > > clock for the core controller. Given a maximum of 32 DMA channels, the
> > > > maximum clock number consequently increases to 33.
> > > >
> > > > Signed-off-by: Joy Zou <joy.zou@xxxxxxx>
> > > > Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
> > > > ---
> > > >  .../devicetree/bindings/dma/fsl,edma.yaml          | 26 ++++++++++++++++++++--
> > > >  1 file changed, 24 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/dma/fsl,edma.yaml b/Documentation/devicetree/bindings/dma/fsl,edma.yaml
> > > > index aa51d278cb67b..55cce79c759f8 100644
> > > > --- a/Documentation/devicetree/bindings/dma/fsl,edma.yaml
> > > > +++ b/Documentation/devicetree/bindings/dma/fsl,edma.yaml
> > > > @@ -23,6 +23,7 @@ properties:
> > > >            - fsl,imx7ulp-edma
> > > >            - fsl,imx8qm-adma
> > > >            - fsl,imx8qm-edma
> > > > +          - fsl,imx8ulp-edma
> > > >            - fsl,imx93-edma3
> > > >            - fsl,imx93-edma4
> > > >            - fsl,imx95-edma5
> > > > @@ -53,11 +54,11 @@ properties:
> > > >
> > > >    clocks:
> > > >      minItems: 1
> > > > -    maxItems: 2
> > > > +    maxItems: 33
> > > >
> > > >    clock-names:
> > > >      minItems: 1
> > > > -    maxItems: 2
> > > > +    maxItems: 33
> > > >
> > > >    big-endian:
> > > >      description: |
> > > > @@ -108,6 +109,7 @@ allOf:
> > > >        properties:
> > > >          clocks:
> > > >            minItems: 2
> > > > +          maxItems: 2
> > > >          clock-names:
> > > >            items:
> > > >              - const: dmamux0
> > > > @@ -136,6 +138,7 @@ allOf:
> > > >        properties:
> > > >          clock:
> > > >            minItems: 2
> > > > +          maxItems: 2
> > > >          clock-names:
> > > >            items:
> > > >              - const: dma
> > > > @@ -151,6 +154,25 @@ allOf:
> > > >          dma-channels:
> > > >            const: 32
> > > >
> > > > +  - if:
> > > > +      properties:
> > > > +        compatible:
> > > > +          contains:
> > > > +            const: fsl,imx8ulp-edma
> > > > +    then:
> > > > +      properties:
> > > > +        clock:
> > >
> > > clocks
> > >
> > > > +          maxItems: 33
> > >
> > > That is already the max. I think you want 'minItems: 33' here.
> > >
> > > > +        clock-names:
> > > > +          items:
> > > > +            - const: dma
> > > > +            - pattern: "^CH[0-31]-clk$"
> > >
> > > '-clk' is redundant. [0-31] is not how you do a range of numbers with
> > > regex.
> > >
> > > This doesn't cover clocks 3-33. Not a great way to express in
> > > json-schema, but this should do it:
> > >
> > > allOf:
> > >   - items:
> > >       - const: dma
> > >   - items:
> > >       oneOf:
> > >         - const: dma
> > >         - pattern: "^ch([0-9]|[1-2][0-9]|[3[01])$"
> >
> > I understand pattern is wrong. But I don't understand why need 'allOf'.
> 
> The first 'items' says the 1st entry must be 'dma'. (It might need a
> 'maxItems: 33' too now that I look at it.) The 2nd 'items' says all
> entries must be either 'dma' or the CHn pattern.

After dig into dt_scheme and json scheme, I start understand what your
means.

"clock-names": {                                   
    "minItems": 33,                                
    "allOf": [                                     
         {                                          
            "items": [                             
                 {                                  
                     "const": "dma"                 
                 }                                  
            ],                                     
            "maxItems": 33, 
            ^^^^^^^^
      Here need a maxItem 33 and make sure first item is "dma" and total
array is 33.                       

            "type": "array",                       
            "minItems": 1                          
         },                                         
         {                                          
            "items": {                             
            "oneOf": [                         
                 {                              
                      "const": "dma"             
                 },                             
                 {                              
                       "pattern": "^ch(0[0-9]|[1-2][0-9]|3[01])$"
                 }                              
                 ]                                  
            },                                     
            "type": "array"                        
         }                                          
    ]                                              
}

The yaml source is

          allOf:                                                           
            - items:                                                       
                - const: dma                                               
              maxItems: 33                                                 
            - items:                                                       
                oneOf:                                                     
                  - const: dma                                             
                  - pattern: "^ch(0[0-9]|[1-2][0-9]|3[01])$"


But unfortunately, 

dtschema/meta-schemas/items.yaml

    type: object                                                         
      properties:                                                          
        items:                                                             
          type: array                                                      
        additionalItems: false                                             
      required:                                                            
        - items                                                            
        - maxItems                                                         
    then:                                                                  
      description: '"maxItems" is not needed with an "items" list'         
      not:                                                                 
        required:                                                          
          - maxItem


dt_binding check will complain
	'"maxItems" is not needed with an "items" list'


I am not sure how to go futher. Maybe below 'stupid' method is less impact.

items
  - const: dma
  - const: ch00
  ...
  - const: ch31
	  

Frank

> 
> > 8ulp need clock 'dma" and "ch*". I think
> >
> > items:
> >     - const: dma
> >     - pattern: "^CH[0-31]-clk$"
> >
> > should be enough.
> 
> If it was, then I would not have said anything. If you don't believe
> me see if this passes validation:
> 
> clock-names = "dma", "CH0", "foobar";
> 
> > If you means put on top allOf, other platform use clock name such as
> > 'dmamux0'.
> 
> What? It's under an if/then schema.
> 
> Rob