Re: [PATCH v6 08/30] dt-bindings: soc: fsl: cpm_qe: cpm1-scc-qmc: Add support for QMC HDLC

Hi Krzysztof,

On Sat, 23 Sep 2023 19:39:49 +0200 Krzysztof Kozlowski krzysztof.kozlowski@linaro.org wrote:

On 22/09/2023 09:58, Herve Codina wrote:

...

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

.../soc/fsl/cpm_qe/fsl,cpm1-scc-qmc.yaml | 24 +++++++++++++++++++ 1 file changed, 24 insertions(+)

diff --git a/Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,cpm1-scc-qmc.yaml b/Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,cpm1-scc-qmc.yaml index 82d9beb48e00..61dfd5ef7407 100644 --- a/Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,cpm1-scc-qmc.yaml +++ b/Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,cpm1-scc-qmc.yaml @@ -101,6 +101,27 @@ patternProperties: Channel assigned Rx time-slots within the Rx time-slots routed by the TSA to this cell.

•  compatible:
  

•    const: fsl,qmc-hdlc  
  

Why this is not a device/SoC specific compatible?

This compatible is present in a QMC channel. The parent node (the QMC itself) contains a compatible with device/SoC: --- 8< --- compatible: items: - enum: - fsl,mpc885-scc-qmc - fsl,mpc866-scc-qmc - const: fsl,cpm1-scc-qmc --- 8< ---

At the child level (ie QMC channel), I am not sure that adding device/SoC makes sense. This compatible indicates that the QMC channel is handled by the QMC HDLC driver. At this level, whatever the device/SoC, we have to be QMC compliant.

With these details, do you still think I need to change the child (channel) compatible ?

...

•  fsl,framer:
  

•    $ref: /schemas/types.yaml#/definitions/phandle
  

•    description:
  

•      phandle to the framer node. The framer is in charge of an E1/T1 line
  

•      interface connected to the TDM bus. It can be used to get the E1/T1 line
  

•      status such as link up/down.
  

• allOf:

•  - if:
  

•      properties:
  

•        compatible:
  

•          not:
  

•            contains:
  

•              const: fsl,qmc-hdlc
  

•    then:
  

•      properties:
  

•        fsl,framer: false
  

• required: - reg - fsl,tx-ts-mask

@@ -159,5 +180,8 @@ examples: fsl,operational-mode = "hdlc"; fsl,tx-ts-mask = <0x00000000 0x0000ff00>; fsl,rx-ts-mask = <0x00000000 0x0000ff00>;

•        compatible = "fsl,qmc-hdlc";  
  

compatible is always the first property.

Will be moved to the first property in the next iteration.

Best regards, Hervé

...

•        fsl,framer = <&framer>;
     };
  

  };

Best regards, Krzysztof