RE: [PATCH v1 1/3] dt-bindings: fu540: prci: convert PRCI bindings to json-schema

[Sagar Kadam <sagar.kadam@xxxxxxxxxxxx>]

Hello Stephen,

> -----Original Message-----
> From: Stephen Boyd <sboyd@xxxxxxxxxx>
> Sent: Tuesday, September 15, 2020 5:37 AM
> To: Sagar Kadam <sagar.kadam@xxxxxxxxxxxx>;
> devicetree@xxxxxxxxxxxxxxx; linux-clk@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; linux-pwm@xxxxxxxxxxxxxxx; linux-
> riscv@xxxxxxxxxxxxxxxxxxx
> Cc: mturquette@xxxxxxxxxxxx; robh+dt@xxxxxxxxxx; Paul Walmsley ( Sifive)
> <paul.walmsley@xxxxxxxxxx>; palmer@xxxxxxxxxxx; tglx@xxxxxxxxxxxxx;
> jason@xxxxxxxxxxxxxx; maz@xxxxxxxxxx; thierry.reding@xxxxxxxxx;
> u.kleine-koenig@xxxxxxxxxxxxxx; lee.jones@xxxxxxxxxx;
> aou@xxxxxxxxxxxxxxxxx; Yash Shah <yash.shah@xxxxxxxxxxxx>; Sagar
> Kadam <sagar.kadam@xxxxxxxxxxxx>
> Subject: Re: [PATCH v1 1/3] dt-bindings: fu540: prci: convert PRCI bindings
> to json-schema
> 
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> 
> Quoting Sagar Kadam (2020-09-10 03:44:02)
> > diff --git
> > a/Documentation/devicetree/bindings/clock/sifive/fu540-prci.yaml
> > b/Documentation/devicetree/bindings/clock/sifive/fu540-prci.yaml
> > new file mode 100644
> > index 0000000..49386cd
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/clock/sifive/fu540-prci.yaml
> > @@ -0,0 +1,75 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) # Copyright
> > +(C) 2020 SiFive, Inc.
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/clock/sifive/fu540-prci.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: SiFive FU540 Power Reset Clock Interrupt Controller (PRCI)
> > +
> > +maintainers:
> > +  - Sagar Kadam <sagar.kadam@xxxxxxxxxx>
> > +  - Paul Walmsley  <paul.walmsley@xxxxxxxxxx>
> > +
> > +description:
> > +  On the FU540 family of SoCs, most system-wide clock and reset
> > +integration
> > +  is via the PRCI IP block.
> > +  The clock consumer should specify the desired clock via the clock
> > +ID
> > +  macros defined in include/dt-bindings/clock/sifive-fu540-prci.h.
> > +  These macros begin with PRCI_CLK_.
> > +
> > +  The hfclk and rtcclk nodes are required, and represent physical
> > + crystals or resonators located on the PCB.  These nodes should be
> > + present  underneath /, rather than /soc.
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - sifive,fu540-c000-prci
> > +    description:
> > +      Should have "sifive,<soc>-prci", only one value is supported
> 
> Drop description and have
> 
>     compatible:
>       const: sifive,fu540-c000-prci
> 
Thank you for suggestion here, I will remove this.
> > +
> > +  reg:
> > +    maxItems: 1
> > +    description: Describe the PRCI's register target physical address
> > + region
> 
> Drop description.
> 
Okay.
> > +
> > +  clocks:
> > +    description:
> > +      Should point to the hfclk device tree node and the rtcclk device tree
> node.
> 
> s/device tree node//g

Okay, will remove these.

> 
> > +      The RTC clock here is not a time-of-day clock, but is instead a high-
> stability
> > +      clock source for system timers and cycle counters.
> 
> Better to have:
> 
>     clocks:
>       items:
>         - const: high frequency clock
>         - const: RTC clock
> 
> Can you add clock-names too? Making it optional is OK.
Okay, I will include these optional properties as
            -const: "hfclk"
            -const: "rtcclk"
> 
> > +  "#clock-cells":
> > +    const: 1
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - clocks
> > +  - "#clock-cells"
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    //hfclk and rtcclk present under /, in PCB-specific DT data
> > +    hfclk: hfclk {
> > +      #clock-cells = <0>;
> > +      compatible = "fixed-clock";
> > +      clock-frequency = <33333333>;
> > +      clock-output-names = "hfclk";
> > +    };
> 
> Add a newline here?
> 
Okay.
> > +    rtcclk: rtcclk {
> > +      #clock-cells = <0>;
> > +      compatible = "fixed-clock";
> > +      clock-frequency = <1000000>;
> > +      clock-output-names = "rtcclk";
> > +    };
> 
> These may not be necessary either, just have the clock-controller node
> reference phandles?
> 
Okay.
> > +
> > +    //under /soc, in SoC-specific DT data
> 
> Don't think this comment is necessary.
> 
Okay.

Thanks & BR,
Sagar

> > +    prci: clock-controller@10000000 {
> > +      compatible = "sifive,fu540-c000-prci";
> > +      reg = <0x10000000 0x1000>;
> > +      clocks = <&hfclk>, <&rtcclk>;
> > +      #clock-cells = <1>;
> > +    };