Re: [PATCH v6 2/2] coresight: add coresight Trace Network On Chip driver

[Suzuki K Poulose <suzuki.poulose@arm.com>]

On 22/05/2025 09:07, Yuanfang Zhang wrote:
> Add a driver to support Coresight device Trace Network On Chip (TNOC),
> which is an integration hierarchy integrating functionalities of TPDA
> and funnels. It aggregates the trace and transports to coresight trace
> bus.
> 
> Compared to current configuration, it has the following advantages:
> 1. Reduce wires between subsystems.
> 2. Continue cleaning the infrastructure.
> 3. Reduce Data overhead by transporting raw data from source to target.
> 
>    +------------------------+                +-------------------------+
>    | Video Subsystem        |                |Video Subsystem          |
>    |       +-------------+  |                |       +------------+    |
>    |       | Video TPDM  |  |                |       | Video TPDM |    |
>    |       +-------------+  |                |       +------------+    |
>    |            |           |                |              |          |
>    |            v           |                |              v          |
>    |   +---------------+    |                |        +-----------+    |
>    |   | Video funnel  |    |                |        |Video TNOC |    |
>    |   +---------------+    |                |        +-----------+    |
>    +------------|-----------+                +------------|------------+
>                 |                                         |
>                 v-----+                                   |
> +--------------------|---------+                         |
> |  Multimedia        v         |                         |
> |  Subsystem   +--------+      |                         |
> |              |  TPDA  |      |                         v
> |              +----|---+      |              +---------------------+
> |                   |          |              |   Aggregator  TNOC  |
> |                   |          |              +----------|----------+
> |                   +--        |                         |
> |                     |        |                         |
> |                     |        |                         |
> |              +------v-----+  |                         |
> |              |  Funnel    |  |                         |
> |              +------------+  |                         |
> +----------------|-------------+                         |
>                   |                                       |
>                   v                                       v
>        +--------------------+                    +------------------+
>        |   Coresight Sink   |                    |  Coresight Sink  |
>        +--------------------+                    +------------------+
> 
>         Current Configuration                            TNOC
> 
> Signed-off-by: Yuanfang Zhang <quic_yuanfang@quicinc.com>


> +
> +static int trace_noc_init_default_data(struct trace_noc_drvdata *drvdata)
> +{
> +	int atid;
> +
> +	atid = coresight_trace_id_get_system_id();
> +	if (atid < 0)
> +		return atid;
> +
> +	drvdata->atid = atid;

Do you need to expose this via sysfs ? Otherwise, how can you map
a trace to a TNOC at decoding ?

Suzuki