Re: [PATCH 06/14] dt-bindings: clock: milbeaut: add Milbeaut clock description

[Sugaya, Taichi]

Hi,

Thank you for your comments.

On 2018/11/30 17:19, Stephen Boyd wrote:
> Quoting Sugaya Taichi (2018-11-18 17:01:11)
> > Add DT bindings document for Milbeaut clock.
> >
> > Signed-off-by: Sugaya Taichi <sugaya.taichi@xxxxxxxxxxxxx>
> > ---
> >   .../devicetree/bindings/clock/milbeaut-clock.txt   | 93 ++++++++++++++++++++++
> >   1 file changed, 93 insertions(+)
> >   create mode 100644 Documentation/devicetree/bindings/clock/milbeaut-clock.txt
> >
> > diff --git a/Documentation/devicetree/bindings/clock/milbeaut-clock.txt b/Documentation/devicetree/bindings/clock/milbeaut-clock.txt
> > new file mode 100644
> > index 0000000..5c093c8
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/clock/milbeaut-clock.txt
> > @@ -0,0 +1,93 @@
> > +Milbeaut M10V Clock Controller Binding
> > +----------------------------------------
> > +Milbeaut clock controller is consists of few oscillators, PLL, multiplexer
> > +and few divider modules
> > +
> > +This binding uses common clock bindings
> > +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
> > +
> > +Required properties:
> > +- compatible: shall be "socionext,milbeaut-m10v-clk-regs"
> > +- reg: shall contain base address and length of clock registers
> > +- #clock-cells: shall be 0
> > +
> > +Example:
> > +       m10v-clk-tree@ {
> > +               compatible = "socionext,milbeaut-m10v-clk-regs";
> > +               reg = <0x1d021000 0x4000>;
> > +
> > +               clocks {
> > +                       #address-cells = <0>;
> > +                       #size-cells = <0>;
> > +
> > +                       uclk40xi: uclk40xi {
> > +                               compatible = "fixed-clock";
> > +                               #clock-cells = <0>;
> > +                               clock-frequency = <40000000>;
> > +                       };
> > +               };
>
> This style of binding is highly discouraged. We don't describe each and
> every clk in DT, we describe clk controllers and their outputs and
> inputs in DT. The driver is the place where the clock controller
> describes the internal clk topology of that controller. Also, fixed
> frequency clks are typically oscillators and those would come from the
> board dts file, but otherwise I wouldn't expect to see fixed frequency
> clks in DT.

I understand. Received the similar comment from Rob in the DT part also.

> > +       }
> > +
> > +The clock consumer shall specify the desired clock-output of the clock
> > +controller (as defined in [2]) by specifying output-id in its "clock"
> > +phandle cell
> > +[2] arch/arm/boot/dts/milbeaut-m10v-clk.h
> > +
> [...]
> > +
> > +Example
> > +       piclk_mux_0: spiclk_mux_0 {
> > +               compatible = "socionext,m10v-clk-div";
> > +               #clock-cells = <0>;
> > +               clocks = <&pll10_div_1_2>;
> > +               offset = <bSPICLK>;
> > +               mask = <0x3>;
> > +               ratios = <4 0x5 2 0x4>;
> > +       };
> > +
> > +       pll10: pll10 {
> > +               compatible = "socionext,m10v-pll-fixed-factor";
> > +               #clock-cells = <0>;
> > +               clocks = <&uclk40xi>;
> > +               offset = <10>;
> > +               clock-div = <5>;
> > +               clock-mult = <108>;
> > +       };
> > +
> > +       emmcclk: emmcclk {
> > +               compatible = "socionext,m10v-clk-div";
> > +               #clock-cells = <0>;
> > +               clocks = <&pll11>;
> > +               offset = <bEMMCCLK>;
> > +               mask = <0x3>;
> > +               ratios = <15 0x7 10 0x6 9 0x5 8 0x4>;
>
> Yeah, please no. This whole binding needs a rewrite to not have one node
> per clk.

OK, I will renew the binding.

Thanks.
Sugaya Taichi

>