Re: [PATCH v3 02/24] dt-bindings: memory: mediatek: Convert SMI to DT schema

[Yong Wu <yong.wu@mediatek.com>]

On Tue, 2020-10-06 at 09:15 +0200, Krzysztof Kozlowski wrote:
> On Tue, 6 Oct 2020 at 06:27, Yong Wu <yong.wu@mediatek.com> wrote:
> >
> > On Fri, 2020-10-02 at 13:08 +0200, Krzysztof Kozlowski wrote:
> > > On Wed, Sep 30, 2020 at 03:06:25PM +0800, Yong Wu wrote:
> > > > Convert MediaTek SMI to DT schema.
> > > >
> > > > Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> > > > ---
> > > >  .../mediatek,smi-common.txt                   |  49 ---------
> > > >  .../mediatek,smi-common.yaml                  | 100 ++++++++++++++++++
> > > >  .../memory-controllers/mediatek,smi-larb.txt  |  49 ---------
> > > >  .../memory-controllers/mediatek,smi-larb.yaml |  91 ++++++++++++++++
> > > >  4 files changed, 191 insertions(+), 98 deletions(-)
> > > >  delete mode 100644 Documentation/devicetree/bindings/memory-controllers/mediatek,smi-common.txt
> > > >  create mode 100644 Documentation/devicetree/bindings/memory-controllers/mediatek,smi-common.yaml
> > > >  delete mode 100644 Documentation/devicetree/bindings/memory-controllers/mediatek,smi-larb.txt
> > > >  create mode 100644 Documentation/devicetree/bindings/memory-controllers/mediatek,smi-larb.yaml
> > ...
> > > > +properties:
> > > > +  compatible:
> > > > +    oneOf:
> > > > +      - enum:
> > > > +          - mediatek,mt2701-smi-common
> > > > +          - mediatek,mt2712-smi-common
> > > > +          - mediatek,mt6779-smi-common
> > > > +          - mediatek,mt8173-smi-common
> > > > +          - mediatek,mt8183-smi-common
> > > > +
> > > > +      - description: for mt7623
> > > > +        items:
> > > > +          - const: mediatek,mt7623-smi-common
> > > > +          - const: mediatek,mt2701-smi-common
> > > > +
> > > > +  reg:
> > > > +    maxItems: 1
> > > > +
> > > > +  clocks:
> > > > +    description: |
> > > > +      apb and smi are mandatory. the async is only for generation 1 smi HW.
> > > > +      gals(global async local sync) also is optional, here is the list which
> > > > +      require gals: mt6779 and mt8183.
> > > > +    minItems: 2
> > > > +    maxItems: 4
> > > > +    items:
> > > > +      - description: apb is Advanced Peripheral Bus clock, It's the clock for
> > > > +          setting the register.
> > > > +      - description: smi is the clock for transfer data and command.
> > > > +      - description: async is asynchronous clock, it help transform the smi clock
> > > > +          into the emi clock domain.
> > > > +      - description: gals0 is the path0 clock of gals.
> > > > +      - description: gals1 is the path1 clock of gals.
> > > > +
> > > > +  clock-names:
> > > > +    oneOf:
> > > > +      - items:
> > > > +          - const: apb
> > > > +          - const: smi
> > > > +      - items:
> > > > +          - const: apb
> > > > +          - const: smi
> > > > +          - const: async
> > > > +      - items:
> > > > +          - const: apb
> > > > +          - const: smi
> > > > +          - const: gals0
> > > > +          - const: gals1
> > >
> > > Similarly to my comment to other properties, this requirement per
> > > compatible should be part of the schema within 'if-then'.
> >
> > I'm not so familiar with this format. Do this has "if-then-'else
> > if'-then-else"?
> 
> These are mutually exclusive conditions, so you can skip else:
>  - if-then
>  - if-then
>  - if-then
> It will be more readable then stacking 'if' under 'else'

Thanks. I will use something like this:

 anyOf:
   - if: #gen1 hw
     then:
       use apb/smi/async clocks

   - if: #gen2 hw that has gals.
     then:
       use apb/smi/gals0/gals1 clocks
     else: # gen2 hw that doesn't have gals.
       use apb/smi clocks.

> 
> >
> > I tried below instead of the clocks segment above:
> >
> > ===================================
> > if:
> >   properties:
> >     compatible:
> 
> Missing contains. Just take an example from some existing schema.


Like the example you gave below
(Documentation/devicetree/bindings/clock/idt,versaclock5.yaml), It also
doesn't have "contains" in "if". I guess it is unnecessary if there is
only one compatible string. it may be necessary when it has backward
compatible string.

> 
> >       enum:
> >         - mediatek,mt6779-smi-common
> >         - mediatek,mt8183-smi-common
> >
> > then:
> >   properties:
> >     clock:
> >       items:
> >         - description: apb is the clock for setting the register..
> >         - description: smi is the clock for transfer data and command.
> >         - description: gals0 is the path0 clock of gals(global async
> > local sync).
> >         - description: gals1 is the path1 clock of gals.
> >     clock-names:
> >       items:
> >         - const: apb
> >         - const: smi
> >         - const: gals0
> >         - const: gals1
> > else:
> >   if:
> >     properties:
> >       compatible:
> >         contains:
> >           enum:
> >             - mediatek,mt2701-smi-common
> >
> >   then:
> >     properties:
> >       clocks:
> >         items:
> >           - description: apb is the clock for setting the register.
> >           - description: smi is the clock for transfer data and command.
> >           - description: async is asynchronous clock, it help transform
> > the smi clock
> >               into the emi clock domain.
> >       clock-names:
> >         items:
> >           - const: apb
> >           - const: smi
> >           - const: async
> >   else:
> >     properties:
> >       clocks:
> >         items:
> >           - description: apb is the clock for setting the register.
> >           - description: smi is the clock for transfer data and
> > command.
> >       clock-names:
> >         items:
> >           - const: apb
> >           - const: smi
> > ================================
> >
> > But I got a warning when dt_binding_check:
> >
> > CHKDT
> > Documentation/devicetree/bindings/memory-controllers/mediatek,smi-common.yaml
> >   SCHEMA
> > Documentation/devicetree/bindings/processed-schema-examples.yaml
> >   DTC
> > Documentation/devicetree/bindings/memory-controllers/mediatek,smi-common.example.dt.yaml
> >   CHECK
> > Documentation/devicetree/bindings/memory-controllers/mediatek,smi-common.example.dt.yaml
> > .../Documentation/devicetree/bindings/memory-controllers/mediatek,smi-common.example.dt.yaml: smi@14022000: 'clock-names', 'clocks' do not match any of the regexes: 'pinctrl-[0-9]+'
> 
> There are several files which already choose different clocks based on
> compatible, simple grep shows them:
> Documentation/devicetree/bindings/iio/adc/samsung,exynos-adc.yaml
> Documentation/devicetree/bindings/clock/idt,versaclock5.yaml

Thanks for the review. I will send the next version after v5.10.

> 
> Best regards,
> Krzysztof