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:

quoted

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 <redacted>
---
 .../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@quicinc.com>
+  - Mao Jinlong <quic_jinlmao@quicinc.com>
+  - Jie Gan <quic_jiegan@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.

The in-ports listed below illustrate their connection to TMC devices.

quoted

+
+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

quoted

+    $ref: /schemas/graph.yaml#/properties/ports
+
+    patternProperties:
+      '^port(@[0-7])?$':
+        description: Input connections from CoreSight Trace bus
+        $ref: /schemas/graph.yaml#/properties/port
+
+required:
+  - compatible
+  - reg
+  - in-ports
+
+additionalProperties: false
+
+examples:
+  - |
+    ctcu@1001000 {
+        compatible = "qcom,sa8775p-ctcu";
+        reg = <0x1001000 0x1000>;
+
+        clocks = <&aoss_qmp>;
+        clock-names = "apb";
+
+        in-ports {
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            port@0 {
+                reg = <0>;
+                ctcu_in_port0: endpoint {
+                    remote-endpoint = <&etr0_out_port>;
+                };
+            };
+
+            port@1 {
+                reg = <1>;
+                ctcu_in_port1: endpoint {
+                    remote-endpoint = <&etr1_out_port>;
+                };
+            };
+        };
+    };
-- 
2.34.1

Thanks,
Jie