Re: [PATCH v4 2/3] dt-bindings: arm: Add Coresight Dummy Trace

On Fri, May 05, 2023 at 11:54:03AM +0100, Suzuki Kuruppassery Poulose wrote:

[...]

...

+title: ARM Coresight Dummy component

+description: |

• Coresight Dummy Trace Module is for the specific devices that kernel
• don't have permission to access or configure, e.g., CoreSight TPDMs
• on Qualcomm platforms. So there need driver to register dummy devices
• as Coresight devices. It may also be used to define components that
• may not have any programming interfaces (e.g, static links), so that
• paths can be established in the driver. Provide Coresight API for
• dummy device operations, such as enabling and disabling dummy devices.
• Build the Coresight path for dummy sink or dummy source for debugging. > +
• The primary use case of the coresight dummy is to build path in kernel
• side for dummy sink and dummy source.

+maintainers:

• • Mao Jinlong quic_jinlmao@quicinc.com
• • Tao Zhang quic_taozha@quicinc.com
• • Hao Zhang quic_hazha@quicinc.com
• • Yuanfang Zhang quic_yuanfang@quicinc.com

Given this is a generic "CoreSight" component, I would prefer to have the CoreSight subsystem maintainers listed here (too). I don't mind the entries above, but would like to make sure that the subsystem people are aware of the changes happening here. Please use:

Mike Leach mike.leach@linaro.org Suzuki K Poulose suzuki.poulose@arm.com Leo Yan leo.yan@linaro.org

Given I am spending little time on CoreSight reviewing, I'd like to use James Clark's email address to replace my own; I believe this would benefit long term maintenance.

James Clark james.clark@arm.com

Thanks!

With the above:

Acked-by: Suzuki K Poulose suzuki.poulose@arm.com

...

+properties:

• compatible:
• items:

•  - enum:
  

•      - arm,coresight-dummy-sink
  

•      - arm,coresight-dummy-source
  

• out-ports:
• $ref: /schemas/graph.yaml#/properties/ports
• properties:

•  port:
  

•    description: Output connection from the source to Coresight
  

•      Trace bus.
  

•    $ref: /schemas/graph.yaml#/properties/port
  

• in-ports:
• $ref: /schemas/graph.yaml#/properties/ports
• properties:

•  port:
  

•    description: Input connection from the Coresight Trace bus to
  

•      dummy sink, such as Embedded USB debugger(EUD).
  

•    $ref: /schemas/graph.yaml#/properties/port
  

+required:

• • compatible

+if:

• # If the compatible contains the below value
• properties:
• compatible:

•  contains:
  

•    const: arm,coresight-dummy-sink
  

+then:

• required:
• • in-ports

+else:

• required:
• • out-ports

+additionalProperties: false

+examples:

• # Minimum dummy sink definition. Dummy sink connect to coresight replicator.
• • |
• sink {

•  compatible = "arm,coresight-dummy-sink";
  

•  in-ports {
  

•    port {
  

•      eud_in_replicator_swao: endpoint {
  

•        remote-endpoint = <&replicator_swao_out_eud>;
  

•      };
  

•    };
  

•  };
  

• };
• # Minimum dummy source definition. Dummy source connect to coresight funnel.
• • |
• source {

•  compatible = "arm,coresight-dummy-source";
  

•  out-ports {
  

•    port {
  

•      dummy_riscv_out_funnel_swao: endpoint {
  

•        remote-endpoint = <&funnel_swao_in_dummy_riscv>;
  

•      };
  

•    };
  

•  };
  

• };

+...