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

From: Xingyu Wu
Date: Fri Jul 14 2023 - 02:27:51 EST


On 2023/7/13 20:26, Emil Renner Berthing wrote:
> 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.

Will fix.

>
>> + 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.

I prefer to keep these names because they are used in the PLL driver
and are more easy to understand than numbers.
I will use the JH7110_PLLCLK_PLL?_OUT to follow the same pattern
in next version.

Best regards,
Xingyu Wu

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