Re: [RESEND PATCH v6 1/7] dt-bindings: clock: Add StarFive JH7110 PLL clock generator

From: Emil Renner Berthing
Date: Thu Jul 13 2023 - 08:27:11 EST


On Tue, 4 Jul 2023 at 08:49, Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx> wrote:
>
> Add bindings for the PLL clock generator on the JH7110 RISC-V SoC.
>
> Reviewed-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
> Signed-off-by: Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx>
> ---
> .../bindings/clock/starfive,jh7110-pll.yaml | 46 +++++++++++++++++++
> .../dt-bindings/clock/starfive,jh7110-crg.h | 6 +++
> 2 files changed, 52 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/clock/starfive,jh7110-pll.yaml
>
> diff --git a/Documentation/devicetree/bindings/clock/starfive,jh7110-pll.yaml b/Documentation/devicetree/bindings/clock/starfive,jh7110-pll.yaml
> new file mode 100644
> index 000000000000..beb78add5a8d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/starfive,jh7110-pll.yaml
> @@ -0,0 +1,46 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/clock/starfive,jh7110-pll.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: StarFive JH7110 PLL Clock Generator
> +
> +description:
> + These PLLs are high speed, low jitter frequency synthesizers in JH7110.

..synthesizers in the JH7110.

> + Each PLL works in integer mode or fraction mode, with configuration
> + registers in the sys syscon. So the PLLs node should be a child of
> + SYS-SYSCON node.
> + The formula for calculating frequency is
> + Fvco = Fref * (NI + NF) / M / Q1
> +
> +maintainers:
> + - Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx>
> +
> +properties:
> + compatible:
> + const: starfive,jh7110-pll
> +
> + clocks:
> + maxItems: 1
> + description: Main Oscillator (24 MHz)
> +
> + '#clock-cells':
> + const: 1
> + description:
> + See <dt-bindings/clock/starfive,jh7110-crg.h> for valid indices.
> +
> +required:
> + - compatible
> + - clocks
> + - '#clock-cells'
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + clock-controller {
> + compatible = "starfive,jh7110-pll";
> + clocks = <&osc>;
> + #clock-cells = <1>;
> + };
> diff --git a/include/dt-bindings/clock/starfive,jh7110-crg.h b/include/dt-bindings/clock/starfive,jh7110-crg.h
> index 06257bfd9ac1..086a6ddcf380 100644
> --- a/include/dt-bindings/clock/starfive,jh7110-crg.h
> +++ b/include/dt-bindings/clock/starfive,jh7110-crg.h
> @@ -6,6 +6,12 @@
> #ifndef __DT_BINDINGS_CLOCK_STARFIVE_JH7110_CRG_H__
> #define __DT_BINDINGS_CLOCK_STARFIVE_JH7110_CRG_H__
>
> +/* PLL clocks */
> +#define JH7110_CLK_PLL0_OUT 0
> +#define JH7110_CLK_PLL1_OUT 1
> +#define JH7110_CLK_PLL2_OUT 2
> +#define JH7110_PLLCLK_END 3

It would be nice if these names followed the same pattern as the
clocks below. Eg. something like JH7110_PLLCLK_PLL?_OUT and
JH7110_PLLCLK_END.

But maybe these defines are not even needed, since you just do <&pll
0>, <&pll 1> and it's obvious what that means.

> /* SYSCRG clocks */
> #define JH7110_SYSCLK_CPU_ROOT 0
> #define JH7110_SYSCLK_CPU_CORE 1
> --
> 2.25.1
>