RE: [RFC PATCH] dt-bindings: net: ethernet-controller: Add ptimer_handle

["Gaddam, Sarath Babu Naidu" <sarath.babu.naidu.gaddam@amd.com>]

> -----Original Message-----
> From: Sarath Babu Naidu Gaddam <sarath.babu.naidu.gaddam@amd.com>
> Sent: Thursday, September 29, 2022 5:43 PM
> To: davem@davemloft.net; edumazet@google.com; kuba@kernel.org;
> pabeni@redhat.com; robh+dt@kernel.org
> Cc: krzysztof.kozlowski+dt@linaro.org; netdev@vger.kernel.org;
> devicetree@vger.kernel.org; linux-kernel@vger.kernel.org;
> yangbo.lu@nxp.com; Pandey, Radhey Shyam
> <radhey.shyam.pandey@amd.com>; Sarangi, Anirudha
> <anirudha.sarangi@amd.com>; Katakam, Harini
> <harini.katakam@amd.com>; Gaddam, Sarath Babu Naidu
> <sarath.babu.naidu.gaddam@amd.com>
> Subject: [RFC PATCH] dt-bindings: net: ethernet-controller: Add
> ptimer_handle
> 
> There is currently no standard property to pass PTP device index information
> to ethernet driver when they are independent.
> 
> ptimer_handle property will contain phandle to PTP timer node.
> 
> Freescale driver currently has this implementation but it will be good to agree
> on a generic (optional) property name to link to PTP phandle to Ethernet
> node. In future or any current ethernet driver wants to use this method of
> reading the PHC index,they can simply use this generic name and point their
> own PTP timer node, instead of creating seperate property names in each
> ethernet driver DT node.
> 
> axiethernet driver uses this method when PTP support is integrated.
> 
> Example:
> 	fman0: fman@1a00000 {
> 		ptimer-handle = <&ptp_timer0>;
> 	}
> 
> 	ptp_timer0: ptp-timer@1afe000 {
> 		compatible = "fsl,fman-ptp-timer";
> 		reg = <0x0 0x1afe000 0x0 0x1000>;
> 	}
> 
> Signed-off-by: Sarath Babu Naidu Gaddam
> <sarath.babu.naidu.gaddam@amd.com>
> ---
> We want binding to be reviewed/accepted and then make changes in
> freescale binding documentation to use this generic binding.
> 
> DT information:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
> tree/arch/arm64/boot/dts/freescale/qoriq-fman3-0.dtsi#n23
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
> tree/Documentation/devicetree/bindings/net/fsl-fman.txt#n320
> 
> Freescale driver:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
> tree/drivers/net/ethernet/freescale/dpaa/dpaa_ethtool.c#n467
> 
> Changes in V2:
> 1)Added links to reference code snippets.
> 2)Updated commit msg.
> 
> Comments, suggestions and thoughts to have a common name are very
> welcome...!
> ---
>  .../devicetree/bindings/net/ethernet-controller.yaml         | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/net/ethernet-
> controller.yaml b/Documentation/devicetree/bindings/net/ethernet-
> controller.yaml
> index 4b3c590fcebf..7e726d620c6a 100644
> --- a/Documentation/devicetree/bindings/net/ethernet-controller.yaml
> +++ b/Documentation/devicetree/bindings/net/ethernet-controller.yaml
> @@ -155,6 +155,11 @@ properties:
>        - auto
>        - in-band-status
> 
> +  ptimer_handle:
> +    $ref: /schemas/types.yaml#/definitions/phandle
> +    description:
> +      Specifies a reference to a node representing a IEEE1588 timer.
> +
>    fixed-link:
>      oneOf:
>        - $ref: /schemas/types.yaml#/definitions/uint32-array
> --
> 2.25.1

+Richard Cochran for PTP; apologies for missing earlier.

Thanks,
Sarath