Re:Re: [PATCH v4 2/4] dt-bindings: mfd: sprd: Add bindings for ums512 global registers

From: Stephen Boyd
Date: Wed Oct 13 2021 - 21:51:29 EST


Quoting ChunyanZhang (2021-10-13 16:49:40)
> At 2021-10-14 06:04:32, "Stephen Boyd" <sboyd@xxxxxxxxxx> wrote:
> >Quoting Chunyan Zhang (2021-09-22 23:41:35)
> >> diff --git a/Documentation/devicetree/bindings/mfd/sprd,ums512-glbreg.yaml b/Documentation/devicetree/bindings/mfd/sprd,ums512-glbreg.yaml
> >> +
> >> +examples:
> >> + - |
> >> + ap_apb_regs: syscon@71000000 {
> >> + compatible = "sprd,ums512-glbregs", "syscon", "simple-mfd";
> >> + reg = <0x71000000 0x3000>;
> >> + #address-cells = <1>;
> >> + #size-cells = <1>;
> >> + ranges = <0 0x71000000 0x3000>;
> >> +
> >> + clock-controller@0 {
> >> + compatible = "sprd,ums512-apahb-gate";
> >
> >Why is this a subnode of a syscon and simple-mfd? Why not put the>clock-controller@71000000 directly onto the bus? Does making it a child
> >node help somehow?
>
> These clocks are at the same register range with global registers. I originally put them directly onto the bus indeed when submitting the patches for SC9863A clocks last year, and it had a private property named 'sprd,syscon' which could provide regmap for these clocks.
>
> Rob suggested [1] us to make them a child of the syscon, and would not need the private property 'sprd, syscon' then.

Why do you need to use a syscon? Are the registers shared with some
other driver?

2019 was two years ago...