Re: [PATCH v4 06/28] dt-bindings: net: Add support for QMC HDLC

[Rob Herring <robh@kernel.org>]

On Fri, Aug 18, 2023 at 06:39:00PM +0200, Christophe Leroy wrote:
> From: Herve Codina <herve.codina@bootlin.com>
> 
> The QMC (QUICC mutichannel controller) is a controller present in some
> PowerQUICC SoC such as MPC885.
> The QMC HDLC uses the QMC controller to transfer HDLC data.
> 
> Additionally, a framer can be connected to the QMC HDLC.
> If present, this framer is the interface between the TDM bus used by the
> QMC HDLC and the E1/T1 line.
> The QMC HDLC can use this framer to get information about the E1/T1 line
> and configure the E1/T1 line.
> 
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  .../devicetree/bindings/net/fsl,qmc-hdlc.yaml | 46 +++++++++++++++++++
>  1 file changed, 46 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/net/fsl,qmc-hdlc.yaml
> 
> diff --git a/Documentation/devicetree/bindings/net/fsl,qmc-hdlc.yaml b/Documentation/devicetree/bindings/net/fsl,qmc-hdlc.yaml
> new file mode 100644
> index 000000000000..13f3572f0feb
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/net/fsl,qmc-hdlc.yaml
> @@ -0,0 +1,46 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/net/fsl,qmc-hdlc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Freescale/NXP QUICC Multichannel Controller (QMC) HDLC
> +
> +maintainers:
> +  - Herve Codina <herve.codina@bootlin.com>
> +
> +description: |

Don't need '|'

> +  The QMC HDLC uses a QMC (QUICC Multichannel Controller) channel to transfer
> +  HDLC data.
> +
> +properties:
> +  compatible:
> +    const: fsl,qmc-hdlc
> +
> +  fsl,qmc-chan:
> +    $ref: /schemas/types.yaml#/definitions/phandle-array
> +    items:
> +      - items:
> +          - description: phandle to QMC node
> +          - description: Channel number
> +    description:
> +      Should be a phandle/number pair. The phandle to QMC node and the QMC
> +      channel to use.
> +
> +  framer:
> +    $ref: /schemas/types.yaml#/definitions/phandle
> +    description:
> +      phandle to the framer node

What's the framer? 

> +
> +required:
> +  - compatible
> +  - fsl,qmc-chan
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    hdlc {
> +        compatible = "fsl,qmc-hdlc";
> +        fsl,qmc-chan = <&qmc 16>;

Where does this node live? 

QMC is this[1]? Why don't you just add the compatible to channel@10 in 
the QMC node?

Rob

[1] Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,cpm1-scc-qmc.yaml