Re: [PATCH v6 6/9] dt-bindings: arm: add an interrupt property for Coresight CTCU

[Jie Gan <jie.gan@oss.qualcomm.com>]

On 12/4/2025 2:14 AM, Suzuki K Poulose wrote:
> On 08/09/2025 03:01, Jie Gan wrote:
>> Add an interrupt property to CTCU device. The interrupt will be triggered
>> when the data size in the ETR buffer exceeds the threshold of the
>> BYTECNTRVAL register. Programming a threshold in the BYTECNTRVAL register
>> of CTCU device will enable the interrupt.
>>
>> Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
>> Signed-off-by: Jie Gan <jie.gan@oss.qualcomm.com>
>> ---
>>   .../devicetree/bindings/arm/qcom,coresight-ctcu.yaml    | 17 +++++++ 
>> ++++++++++
>>   1 file changed, 17 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/arm/qcom,coresight- 
>> ctcu.yaml b/Documentation/devicetree/bindings/arm/qcom,coresight- 
>> ctcu.yaml
>> index 843b52eaf872..ea05ad8f3dd3 100644
>> --- a/Documentation/devicetree/bindings/arm/qcom,coresight-ctcu.yaml
>> +++ b/Documentation/devicetree/bindings/arm/qcom,coresight-ctcu.yaml
>> @@ -39,6 +39,16 @@ properties:
>>       items:
>>         - const: apb
>> +  interrupts:
>> +    items:
>> +      - description: Byte cntr interrupt for etr0
>> +      - description: Byte cntr interrupt for etr1
>> +
>> +  interrupt-names:
>> +    items:
>> +      - const: etr0
>> +      - const: etr1
> 

Hi Suzuki,

> Why are they named "etr0" "etr1" ? That would be confusing, isn't it, 
> especially with the Linux driver naming things randomly for the TMC-ETRs.
> 

Yes, it will cause misunderstandings since the "etr0" here may not the 
right device we are expecting.

> 
> What we want is the "port" number corresponding to the "TMC-ETR" being
> monitored ?
> 
> Have you explored other options, "port-0", "port-1" ?
> 

I think it's much better. Will update in next version.

Thanks,
Jie

> Suzuki
> 
>> +
>>     in-ports:
>>       $ref: /schemas/graph.yaml#/properties/ports
>> @@ -56,6 +66,8 @@ additionalProperties: false
>>   examples:
>>     - |
>> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
>> +
>>       ctcu@1001000 {
>>           compatible = "qcom,sa8775p-ctcu";
>>           reg = <0x1001000 0x1000>;
>> @@ -63,6 +75,11 @@ examples:
>>           clocks = <&aoss_qmp>;
>>           clock-names = "apb";
>> +        interrupts = <GIC_SPI 270 IRQ_TYPE_EDGE_RISING>,
>> +                     <GIC_SPI 262 IRQ_TYPE_EDGE_RISING>;
>> +        interrupt-names = "etr0",
>> +                          "etr1";
>> +
>>           in-ports {
>>               #address-cells = <1>;
>>               #size-cells = <0>;
>>
> 
>