Re: [PATCH v5 net-next 01/15] dt-bindings: ptp: add NETC Timer PTP clock

[Frank Li <Frank.li@nxp.com>]

On Mon, Aug 25, 2025 at 12:15:18PM +0800, Wei Fang wrote:
> NXP NETC (Ethernet Controller) is a multi-function PCIe Root Complex
> Integrated Endpoint (RCiEP), the Timer is one of its functions which
> provides current time with nanosecond resolution, precise periodic
> pulse, pulse on timeout (alarm), and time capture on external pulse
> support. And also supports time synchronization as required for IEEE
> 1588 and IEEE 802.1AS-2020. So add device tree binding doc for the PTP
> clock based on NETC Timer.
>
> It is worth mentioning that the reference clock of NETC Timer has three
> clock sources,

Nit: reduce such connect words. Just said

"NETC Timer have three reference clock sources. And there are clock mux
inside the NETC Timers. ...

Reviewed-by: Frank Li <Frank.Li@nxp.com>

> but the clock mux is inside the NETC Timer. Therefore, the
> driver will parse the clock name to select the desired clock source. If
> the clocks property is not present, the NETC Timer will use the system
> clock of NETC IP as its reference clock. Because the Timer is a PCIe
> function of NETC IP, the system clock of NETC is always available to the
> Timer.
>
> Signed-off-by: Wei Fang <wei.fang@nxp.com>
>
> ---
> v5 changes:
> Only change the clock names, "ccm_timer" -> "ccm", "ext_1588" -> "ext"
> v4 changes:
> 1. Add the description of reference clock in the commit message
> 2. Improve the description of clocks property
> 3. Remove the description of clock-names because we have described it in
>    clocks property
> 4. Change the node name from ethernet to ptp-timer
> v3 changes:
> 1. Remove the "system" clock from clock-names
> v2 changes:
> 1. Refine the subject and the commit message
> 2. Remove "nxp,pps-channel"
> 3. Add description to "clocks" and "clock-names"
> ---
>  .../devicetree/bindings/ptp/nxp,ptp-netc.yaml | 63 +++++++++++++++++++
>  1 file changed, 63 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/ptp/nxp,ptp-netc.yaml
>
> diff --git a/Documentation/devicetree/bindings/ptp/nxp,ptp-netc.yaml b/Documentation/devicetree/bindings/ptp/nxp,ptp-netc.yaml
> new file mode 100644
> index 000000000000..042de9d5a92b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/ptp/nxp,ptp-netc.yaml
> @@ -0,0 +1,63 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/ptp/nxp,ptp-netc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: NXP NETC V4 Timer PTP clock
> +
> +description:
> +  NETC V4 Timer provides current time with nanosecond resolution, precise
> +  periodic pulse, pulse on timeout (alarm), and time capture on external
> +  pulse support. And it supports time synchronization as required for
> +  IEEE 1588 and IEEE 802.1AS-2020.
> +
> +maintainers:
> +  - Wei Fang <wei.fang@nxp.com>
> +  - Clark Wang <xiaoning.wang@nxp.com>
> +
> +properties:
> +  compatible:
> +    enum:
> +      - pci1131,ee02
> +
> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +    description:
> +      The reference clock of NETC Timer, can be selected between 3 different
> +      clock sources using an integrated hardware mux TMR_CTRL[CK_SEL].
> +      The "ccm" means the reference clock comes from CCM of SoC.
> +      The "ext" means the reference clock comes from external IO pins.
> +      If not present, indicates that the system clock of NETC IP is selected
> +      as the reference clock.
> +
> +  clock-names:
> +    enum:
> +      - ccm
> +      - ext
> +
> +required:
> +  - compatible
> +  - reg
> +
> +allOf:
> +  - $ref: /schemas/pci/pci-device.yaml
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    pcie {
> +        #address-cells = <3>;
> +        #size-cells = <2>;
> +
> +        ptp-timer@18,0 {
> +            compatible = "pci1131,ee02";
> +            reg = <0x00c000 0 0 0 0>;
> +            clocks = <&scmi_clk 18>;
> +            clock-names = "ccm";
> +        };
> +    };
> --
> 2.34.1
>