[PATCH v3 3/5] dt-bindings: arm: Add Coresight TMC Control Unit hardware

[Krzysztof Kozlowski]

On 19/08/2024 03:49, JieGan wrote:
> On Sun, Aug 18, 2024 at 08:28:34AM -0600, Rob Herring wrote:
>> On Mon, Aug 12, 2024 at 10:41:39AM +0800, Jie Gan wrote:
>>> Add binding file to specify how to define a Coresight TMC
>>> Control Unit device in device tree.
>>>
>>> It is responsible for controlling the data filter function
>>> based on the source device's Trace ID for TMC ETR device.
>>> The trace data with that Trace id can get into ETR's buffer
>>> while other trace data gets ignored.
>>>
>>> Signed-off-by: Jie Gan <quic_jiegan at quicinc.com>
>>> ---
>>>  .../bindings/arm/qcom,coresight-ctcu.yaml     | 79 +++++++++++++++++++
>>>  1 file changed, 79 insertions(+)
>>>  create mode 100644 Documentation/devicetree/bindings/arm/qcom,coresight-ctcu.yaml
>>>
>>> diff --git a/Documentation/devicetree/bindings/arm/qcom,coresight-ctcu.yaml b/Documentation/devicetree/bindings/arm/qcom,coresight-ctcu.yaml
>>> new file mode 100644
>>> index 000000000000..7a9580007942
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/arm/qcom,coresight-ctcu.yaml
>>> @@ -0,0 +1,79 @@
>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>>> +%YAML 1.2
>>> +---
>>> +$id: http://devicetree.org/schemas/arm/qcom,coresight-ctcu.yaml#
>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>> +
>>> +title: CoreSight TMC Control Unit
>>> +
>>> +maintainers:
>>> +  - Yuanfang Zhang <quic_yuanfang at quicinc.com>
>>> +  - Mao Jinlong <quic_jinlmao at quicinc.com>
>>> +  - Jie Gan <quic_jiegan at quicinc.com>
>>> +
>>> +description:
>>> +  The Coresight TMC Control unit controls various Coresight behaviors.
>>> +  It works as a helper device when connected to TMC ETR device.
>>> +  It is responsible for controlling the data filter function based on
>>> +  the source device's Trace ID for TMC ETR device. The trace data with
>>> +  that Trace id can get into ETR's buffer while other trace data gets
>>> +  ignored.
>>
>> Nowhere is TMC defined.
> The Coresight TMC control unit(CTCU) connected to Coresight TMC device via replicator and
> works as a helper device to TMC device.

Did you understand the feedback or just responding with whatever to get
rid of reviewers?

> 
> The in-ports listed below illustrate their connection to TMC devices.
> 
>>
>>> +
>>> +properties:
>>> +  compatible:
>>> +    enum:
>>> +      - qcom,sa8775p-ctcu
>>> +
>>> +  reg:
>>> +    maxItems: 1
>>> +
>>> +  clocks:
>>> +    maxItems: 1
>>> +
>>> +  clock-names:
>>> +    items:
>>> +      - const: apb
>>> +
>>> +  in-ports:
>>
>> Use 'ports' unless you have both in and out ports.
> The ‘in-ports’ and ‘out-ports’ properties will be parsed by ‘of_coresight_get_port_parent’
> and their relationships to other devices will be stored in the coresight_platform_data structure.
> 
> for example:
> struct coresight_platform_data {
> 	int nr_inconns;
> 	int nr_outconns;
> 	struct coresight_connection **out_conns;
> 	struct coresight_connection **in_conns;
> };
> 
> https://elixir.bootlin.com/linux/v6.11-rc4/source/drivers/hwtracing/coresight/coresight-platform.c#L147

and? If you respond with some unrelated argument, we will respond with
the same: Use 'ports' unless you have both in and out ports.

Best regards,
Krzysztof