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Message-ID: <e6b0a542-17d9-290e-7c84-8356a38d6802@quicinc.com>
Date:   Mon, 27 Mar 2023 15:38:08 +0800
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Subject: Re: [PATCH v2 2/3] dt-bindings: arm: Add Coresight Dummy Trace YAML
 schema
Content-Language: en-US
To:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Konrad Dybcio <konradybcio@gmail.com>,
        Mike Leach <mike.leach@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Andy Gross <agross@kernel.org>,
        "Paul Walmsley" <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Jonathan Corbet <corbet@lwn.net>
CC:     Leo Yan <leo.yan@linaro.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        <coresight@lists.linaro.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <devicetree@vger.kernel.org>,
        Tingwei Zhang <quic_tingweiz@quicinc.com>,
        Jinlong Mao <quic_jinlmao@quicinc.com>,
        Yuanfang Zhang <quic_yuanfang@quicinc.com>,
        Tao Zhang <quic_taozha@quicinc.com>,
        Trilok Soni <quic_tsoni@quicinc.com>,
        <linux-arm-msm@vger.kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        <linux-doc@vger.kernel.org>
References: <20230324061608.33609-1-quic_hazha@quicinc.com>
 <20230324061608.33609-3-quic_hazha@quicinc.com>
 <e51c200e-6de0-d516-3f32-28367b2f5a95@linaro.org>
From:   Hao Zhang <quic_hazha@quicinc.com>
In-Reply-To: <e51c200e-6de0-d516-3f32-28367b2f5a95@linaro.org>
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Hi Krzysztof,

On 3/25/2023 7:49 PM, Krzysztof Kozlowski wrote:
> On 24/03/2023 07:16, Hao Zhang wrote:
>> Add new coresight-dummy.yaml file describing the bindings required
>> to define coresight dummy trace in the device trees.
>>
> 
> Subject: drop second/last, redundant "YAML schema". The "dt-bindings"
> prefix is already stating that these are bindings and all new must be DT
> schema. You cannot add anything else, so this is redundant.
> 
I will take your advice to drop redundant part of title in the next 
version of patch.
> 
>> Signed-off-by: Hao Zhang <quic_hazha@quicinc.com>
>> ---
>>   .../bindings/arm/qcom,coresight-dummy.yaml    | 118 ++++++++++++++++++
>>   1 file changed, 118 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/arm/qcom,coresight-dummy.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/arm/qcom,coresight-dummy.yaml b/Documentation/devicetree/bindings/arm/qcom,coresight-dummy.yaml
>> new file mode 100644
>> index 000000000000..7b719b084d72
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/arm/qcom,coresight-dummy.yaml
>> @@ -0,0 +1,118 @@
>> +# SPDX-License-Identifier: GPL-2.0-only or BSD-2-Clause
>> +# Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/arm/qcom,coresight-dummy.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: QCOM Coresight Dummy component
>> +
>> +description: |
>> +  The Coresight Dummy component is for the specific devices that HLOS don't have
>> +  permission to access or configure. Such as Coresight sink EUD, some TPDMs etc.
>> +  So there need driver to register dummy devices as Coresight devices. 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 for dummy sink or
>> +  dummy source.
>> +
>> +maintainers:
>> +  - Mao Jinlong <quic_jinlmao@quicinc.com>
>> +  - Tao Zhang <quic_taozha@quicinc.com>
>> +  - Hao Zhang <quic_hazha@quicinc.com>
>> +
>> +select:
>> +  properties:
>> +    compatible:
>> +      contains:
>> +        enum:
>> +          - qcom,coresight-dummy
>> +  required:
>> +    - compatible
> 
> Why do you need the select?
> 
This is a mistake, will remove it in the next version of patch.
>> +
>> +properties:
>> +  $nodename:
>> +    pattern: "^dummy_.*(sink|source)_[0-9]+.*$"
> 
> We do not enforce node names in individual bindings. Why do you need it?
> Plus underscore is not even proper character...
> 
I will remove this node.

>> +  compatible:
>> +    items:
> 
> Drop items. You have only one item, so no need for list.

I will take your advice and update it in the next version of patch.

>> +      - const: qcom,coresight-dummy
>> +
>> +  qcom,dummy-sink:
>> +    type: boolean
>> +    description:
>> +      Indicates that the type of this coresight node is dummy sink.
> 
> You just duplicated property name. Write something useful.
> 
>> +
>> +  qcom,dummy-source:
>> +    type: boolean
>> +    description:
>> +      Indicates that the type of this coresight node is dummy source.
> 
> You just duplicated property name. Write something useful.
> 

Sure, I will add more details for it.

>> +
>> +  out-ports:
>> +    description: |
> 
> No need for |
> 
>> +      Output connections from the dummy source to Coresight Trace bus.
>> +    $ref: /schemas/graph.yaml#/properties/ports
>> +
>> +    properties:
>> +      port:
>> +        description: Output connection from the dummy source to Coresight
>> +            Trace bus.
>> +        $ref: /schemas/graph.yaml#/properties/port
>> +
>> +  in-ports:
>> +    description: |
> 
> Ditto
> 
I will remove it in the next version of patch.

>> +      Input connections from the CoreSight Trace bus to dummy sink.
>> +    $ref: /schemas/graph.yaml#/properties/ports
>> +
>> +    properties:
>> +      port:
>> +        description: Input connection from the Coresight Trace bus to
>> +            dummy sink.
>> +        $ref: /schemas/graph.yaml#/properties/port
>> +
>> +required:
>> +  - compatible
>> +
>> +additionalProperties: false
>> +
>> +oneOf:
>> +  - required:
>> +      - qcom,dummy-sink
>> +  - required:
>> +      - qcom,dummy-source
>> +
>> +examples:
>> +  # minimum dummy sink definition. dummy sink connect to coresight replicator.
>> +  - |
>> +    dummy_sink_1 {
> 
> Node names should be generic, so "sink"
> https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
> 
>> +      compatible = "qcom,coresight-dummy";
>> +      qcom,dummy-sink;
>> +
>> +      in-ports {
>> +        port {
>> +          eud_in_replicator_swao: endpoint {
>> +            remote-endpoint =
>> +              <&replicator_swao_out_eud>;
> 
> Why line break after =?
> 

>> +          };
>> +        };
>> +      };
>> +    };
>> +
>> +  # minimum dummy source definition. dummy source connect to coresight funnel.
> 
> If you use sentences, then start with capital letter.
>

I will update it according to your advice in the next version of patch.

>> +  - |
>> +    dummy_source_1 {
>> +      compatible = "qcom,coresight-dummy";
>> +      qcom,dummy-source;
>> +
>> +      out-ports {
>> +        port {
>> +          dummy_riscv_out_funnel_swao: endpoint {
>> +            remote-endpoint =
>> +              <&funnel_swao_in_dummy_riscv>;
> 
> Why line break?

I copy it from device tree and keep the original format, will correct 
the format in the next version of patch.

Thanks,
Hao

>> +          };
>> +        };
>> +      };
>> +    };
>> +
>> +...
> 
> Best regards,
> Krzysztof
>