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References: <20230704064610.292603-1-xingyu.wu@starfivetech.com> <20230704064610.292603-2-xingyu.wu@starfivetech.com>
In-Reply-To: <20230704064610.292603-2-xingyu.wu@starfivetech.com>
From:   Emil Renner Berthing <emil.renner.berthing@canonical.com>
Date:   Thu, 13 Jul 2023 14:26:42 +0200
Message-ID: <CAJM55Z8vj6KvpKZxRVh0+G_LCXrpnXzOR+oBad-igkHVTD_J=Q@mail.gmail.com>
Subject: Re: [RESEND PATCH v6 1/7] dt-bindings: clock: Add StarFive JH7110 PLL
 clock generator
To:     Xingyu Wu <xingyu.wu@starfivetech.com>
Cc:     linux-riscv@lists.infradead.org, devicetree@vger.kernel.org,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Conor Dooley <conor@kernel.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Hal Feng <hal.feng@starfivetech.com>,
        William Qiu <william.qiu@starfivetech.com>,
        linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org
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Precedence: bulk

On Tue, 4 Jul 2023 at 08:49, Xingyu Wu <xingyu.wu@starfivetech.com> wrote:
>
> Add bindings for the PLL clock generator on the JH7110 RISC-V SoC.
>
> Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> Signed-off-by: Xingyu Wu <xingyu.wu@starfivetech.com>
> ---
>  .../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@starfivetech.com>
> +
> +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
>