Re: [PATCH 1/4] dt-bindings: arm: qcom,coresight-funnel: Add label for multi-ouput

From: Suzuki K Poulose
Date: Fri Mar 22 2024 - 05:45:20 EST


On 22/03/2024 07:02, Tingwei Zhang wrote:
On 3/21/2024 10:42 PM, Rob Herring wrote:
On Thu, Mar 21, 2024 at 04:32:04PM +0800, Tao Zhang wrote:
Add new property "label" to label the source corresponding to the
output connection. When the funnel supports multi-output, this
property needs to be introduced to mark which source component a
certain output connection corresponds to.

Signed-off-by: Tao Zhang <quic_taozha@xxxxxxxxxxx>
---
  .../arm/arm,coresight-dynamic-funnel.yaml     | 34 ++++++++++++++++---
  1 file changed, 30 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/arm/arm,coresight-dynamic-funnel.yaml b/Documentation/devicetree/bindings/arm/arm,coresight-dynamic-funnel.yaml
index 44a1041cb0fc..cde62c286d29 100644
--- a/Documentation/devicetree/bindings/arm/arm,coresight-dynamic-funnel.yaml
+++ b/Documentation/devicetree/bindings/arm/arm,coresight-dynamic-funnel.yaml
@@ -66,13 +66,39 @@ properties:
          $ref: /schemas/graph.yaml#/properties/port
    out-ports:
-    $ref: /schemas/graph.yaml#/properties/ports
-    additionalProperties: false
-
+    type: object
      properties:
+      "#address-cells":
+        const: 1
+
+      "#size-cells":
+        const: 0
+
        port:
+        type: object
+
+    patternProperties:
+      '^port(@[0-7])?$':
+        type: object
          description: Output connection to CoreSight Trace bus
-        $ref: /schemas/graph.yaml#/properties/port

Nope, now you have no constraints on port node properties. Please look
at how other bindings are done to add properties on endpoint node.

Thanks for pointing this out, Rob. Shall we ref port-base and
endpoint-base then add new properties on endpoint? In this way, the redundant code from port schema is not required.
+
+        patternProperties:
+          "^endpoint(@[0-9a-f]+)?$":
+            type: object
+            properties:
+              remote-endpoint:
+                description: |
+                  phandle to an 'endpoint' subnode of a remote device node.
+                  $ref: /schemas/types.yaml#/definitions/phandle

Don't need this.

+              label:
+                description: Label the source corresponding to the output connection
+                $ref: /schemas/types.yaml#/definitions/string

label already has a type.

As this node is an output, aren't you labeling what the destination is,
not the "source"?

Why can't you look at the remote connection to identify what it is?

This funnel can route data stream from different trace source to different output ports. This lable property is added to describe which source is routed to this output port.

For example, the graph is as below. Funnel3 routes trace data from TPDM0 to output[0] and output[0] of funnel3 is connected to input[0] of TPDA0.

Funnel3 and Funnel4 are really Replicators ! How are they Funnels ? Again, my question still stands. Are Funnel(Replicator-renamed)3/4 and Funnel 0/1/2 programmable ?

Suzuki


While Funnels routes trace data from TPDM1 to output[1] which connects to input[1] of TPDA0. Hope that clarifies this a little bit.

|---------|    |---------|    |---------|    |---------|    |---------|
|  TPDM0  |    |  TPDM1  |    |  TPDM2  |    |  TPDM3  |    |  TPDM4  |
|---------|    |---------|    |---------|    |---------|    |---------|
    |               |             |               |              |
    |               |             |               |              |
    |               |             |               |              |
    |-----|   |-----|             |-----|   |-----|              |
          |   |                         |   |                    |
          |   |                         |   |                    |
       [0]|   |[1]                   [0]|   |[1]                 |
     \-------------/               \-------------/        \------------/
      \  FUNNEL0  /                 \  FUNNEL1  /          \  FUNNEL2  /
       -----------                   -----------            -----------
            |                             |                      |
     \-------------/               \-------------/               |
      \  FUNNEL3  /                 \  FUNNEL4  /                |
       -----------                   -----------                 |
          |  |                         |   |
       [0]|  |[1]                   [0]|   |[1]                  |
          |  |----------               |   |                     |
          |            |               |   |                     |
          |-------|    |      |------- |   |          |--------- |
                  |    |      |            |          |
                  |    |      |            |          |
               [0]|    |[1]   |[2]         |[3]       |[4]
           \ ---------------------------------------------------/
            \                     TPDA0                        /
             \                                                /
              ------------------------------------------------


+    oneOf:
+      - required:
+          - port
+      - required:
+          - "#address-cells"
+          - "#size-cells"

The common schema that you removed handles this.

Rob