Re: [PATCH v7 10/23] dt-bindings: clock: imx8m-clock: add phandle to the anatop
From: Krzysztof Kozlowski
Date: Sun Dec 29 2024 - 05:28:59 EST
On Fri, Dec 27, 2024 at 05:56:13PM +0100, Dario Binacchi wrote:
> Adding the phandle to the anatop node will break the ABI but will allow
> for a better description of the clock generation hardware, making the
> dependency of CCM on anatop explicit. Indeed, the CCM receives the PLLs
> generated by anatop as inputs, which, together with the oscillators,
> are used to generate the clocks for the on-chip peripherals.
I don't get this. If this device (CCM?) receives PLLs, then these are
clock inputs, not a phandle.
>
> By doing this, it will also be possible to generalize the CCM driver
> code, which will no longer require the platform's compatible string to
> retrieve the anatop device node.
>
> Signed-off-by: Dario Binacchi <dario.binacchi@xxxxxxxxxxxxxxxxxxxx>
>
> ---
>
> Changes in v7:
> - New
>
> .../devicetree/bindings/clock/imx8m-clock.yaml | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/clock/imx8m-clock.yaml b/Documentation/devicetree/bindings/clock/imx8m-clock.yaml
> index c643d4a81478..b23e639e6389 100644
> --- a/Documentation/devicetree/bindings/clock/imx8m-clock.yaml
> +++ b/Documentation/devicetree/bindings/clock/imx8m-clock.yaml
> @@ -43,12 +43,20 @@ properties:
> ID in its "clocks" phandle cell. See include/dt-bindings/clock/imx8m-clock.h
> for the full list of i.MX8M clock IDs.
>
> + fsl,anatop:
> + $ref: /schemas/types.yaml#/definitions/phandle
> + description:
> + The phandle to the anatop module that outputs the PLLs, which,
> + along with the oscillators, are used to generate the clocks for
> + the on-chip peripherals.
Explain how this is used by this device. If the explanation is "PLLs",
then it is wrong: PLLs are clock inputs.
Best regards,
Krzysztof