Re: [PATCH v2 2/4] dt-bindings: clk: sprd: Add bindings for ums512 clock controller

[Chunyan Zhang]

On Mon, 20 Sept 2021 at 20:42, Rob Herring <robh@xxxxxxxxxx> wrote:
>
> On Fri, Sep 17, 2021 at 3:41 AM Chunyan Zhang <zhang.lyra@xxxxxxxxx> wrote:
> >
> > On Thu, 16 Sept 2021 at 22:29, Rob Herring <robh@xxxxxxxxxx> wrote:
> > >
> > > On Thu, Sep 16, 2021 at 04:47:12PM +0800, Chunyan Zhang wrote:
> > > > From: Chunyan Zhang <chunyan.zhang@xxxxxxxxxx>
> > > >
> > > > Add a new bindings to describe ums512 clock compatible strings.
> > > >
> > > > Signed-off-by: Chunyan Zhang <chunyan.zhang@xxxxxxxxxx>
> > > > ---
> > > >  .../bindings/clock/sprd,ums512-clk.yaml       | 106 ++++++++++++++++++
> > > >  1 file changed, 106 insertions(+)
> > > >  create mode 100644 Documentation/devicetree/bindings/clock/sprd,ums512-clk.yaml
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/clock/sprd,ums512-clk.yaml b/Documentation/devicetree/bindings/clock/sprd,ums512-clk.yaml
> > > > new file mode 100644
> > > > index 000000000000..be3c37180279
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/clock/sprd,ums512-clk.yaml
> > > > @@ -0,0 +1,106 @@
> > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > > +# Copyright 2019-2021 Unisoc Inc.
> > > > +%YAML 1.2
> > > > +---
> > > > +$id: "http://devicetree.org/schemas/clock/sprd,ums512-clk.yaml#";
> > > > +$schema: "http://devicetree.org/meta-schemas/core.yaml#";
> > > > +
> > > > +title: UMS512 Clock Control Unit Device Tree Bindings
> > > > +
> > > > +maintainers:
> > > > +  - Orson Zhai <orsonzhai@xxxxxxxxx>
> > > > +  - Baolin Wang <baolin.wang7@xxxxxxxxx>
> > > > +  - Chunyan Zhang <zhang.lyra@xxxxxxxxx>
> > > > +
> > > > +properties:
> > > > +  "#clock-cells":
> > > > +    const: 1
> > > > +
> > > > +  compatible:
> > > > +    enum:
> > > > +      - sprd,ums512-apahb-gate
> > > > +      - sprd,ums512-ap-clk
> > > > +      - sprd,ums512-aonapb-clk
> > > > +      - sprd,ums512-pmu-gate
> > > > +      - sprd,ums512-g0-pll
> > > > +      - sprd,ums512-g2-pll
> > > > +      - sprd,ums512-g3-pll
> > > > +      - sprd,ums512-gc-pll
> > > > +      - sprd,ums512-aon-gate
> > > > +      - sprd,ums512-audcpapb-gate
> > > > +      - sprd,ums512-audcpahb-gate
> > > > +      - sprd,ums512-gpu-clk
> > > > +      - sprd,ums512-mm-clk
> > > > +      - sprd,ums512-mm-gate-clk
> > > > +      - sprd,ums512-apapb-gate
> > > > +
> > > > +  clocks:
> > > > +    minItems: 1
> > > > +    maxItems: 4
> > > > +    description: |
> > > > +      The input parent clock(s) phandle for this clock, only list fixed
> > > > +      clocks which are declared in devicetree.
> > > > +
> > > > +  clock-names:
> > > > +    minItems: 1
> > > > +    maxItems: 4
> > > > +    items:
> > > > +      - const: ext-26m
> > > > +      - const: ext-32k
> > > > +      - const: ext-4m
> > > > +      - const: rco-100m
> > > > +
> > > > +  reg:
> > > > +    maxItems: 1
> > > > +
> > > > +required:
> > > > +  - compatible
> > > > +  - '#clock-cells'
> > > > +
> > > > +if:
> > > > +  properties:
> > > > +    compatible:
> > > > +      enum:
> > > > +        - sprd,ums512-ap-clk
> > > > +        - sprd,ums512-aonapb-clk
> > > > +        - sprd,ums512-mm-clk
> > > > +then:
> > > > +  required:
> > > > +    - reg
> > > > +
> > > > +else:
> > > > +  description: |
> > > > +    Other UMS512 clock nodes should be the child of a syscon node in
> > > > +    which compatible string should be:
> > > > +            "sprd,ums512-glbregs", "syscon", "simple-mfd"
> > > > +
> > > > +    The 'reg' property for the clock node is also required if there is a sub
> > > > +    range of registers for the clocks.
> > >
> > > In which cases is this not true?
> >
> > Seems not needed, I will remove 'reg' property for this kind of cases.
>
> Wrong direction. Please keep 'reg'. My question is why can't you
> always have it? That is the preference.

Ok. I will address. BTW, do we need 'reg' even though the driver
doesn't read this property? Does that because DT should reflect
hardware topology?

Thanks for the comments,
Chunyan

>
> Rob