[PATCH v6 2/3] dt-bindings: arm: Add support for Coresight dummy trace

From: Hao Zhang
Date: Fri Jun 02 2023 - 04:43:11 EST


This patch add support for Coresight dummy source and dummy sink trace.

Signed-off-by: Hao Zhang <quic_hazha@xxxxxxxxxxx>
---
.../arm/arm,coresight-dummy-sink.yaml | 73 +++++++++++++++++++
.../arm/arm,coresight-dummy-source.yaml | 71 ++++++++++++++++++
2 files changed, 144 insertions(+)
create mode 100644 Documentation/devicetree/bindings/arm/arm,coresight-dummy-sink.yaml
create mode 100644 Documentation/devicetree/bindings/arm/arm,coresight-dummy-source.yaml

diff --git a/Documentation/devicetree/bindings/arm/arm,coresight-dummy-sink.yaml b/Documentation/devicetree/bindings/arm/arm,coresight-dummy-sink.yaml
new file mode 100644
index 000000000000..cb78cfa56702
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/arm,coresight-dummy-sink.yaml
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: GPL-2.0-only or BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/arm,coresight-dummy-sink.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM Coresight Dummy sink component
+
+description: |
+ CoreSight components are compliant with the ARM CoreSight architecture
+ specification and can be connected in various topologies to suit a particular
+ SoCs tracing needs. These trace components can generally be classified as
+ sinks, links and sources. Trace data produced by one or more sources flows
+ through the intermediate links connecting the source to the currently selected
+ sink.
+
+ The Coresight dummy sink component is for the specific coresight sink devices
+ kernel don't have permission to access or configure, e.g., CoreSight EUD on
+ Qualcomm platforms. It is a mini-USB hub implemented to support the USB-based
+ debug and trace capabilities. For this device, a dummy driver is needed to
+ register it as Coresight sink device in kernel side, so that path can be
+ created in the driver. Then the trace flow would be transferred to EUD via
+ coresight link of AP processor. It provides Coresight API for operations on
+ dummy source devices, such as enabling and disabling them. It also provides
+ the Coresight dummy source paths for debugging.
+
+ The primary use case of the coresight dummy sink is to build path in kernel
+ side for dummy sink component.
+
+maintainers:
+ - Mike Leach <mike.leach@xxxxxxxxxx>
+ - Suzuki K Poulose <suzuki.poulose@xxxxxxx>
+ - James Clark <james.clark@xxxxxxx>
+ - Mao Jinlong <quic_jinlmao@xxxxxxxxxxx>
+ - Hao Zhang <quic_hazha@xxxxxxxxxxx>
+
+properties:
+ compatible:
+ enum:
+ - arm,coresight-dummy-sink
+
+ in-ports:
+ $ref: /schemas/graph.yaml#/properties/ports
+
+ properties:
+ port:
+ description: Input connection from the Coresight Trace bus to
+ dummy sink, such as Embedded USB debugger(EUD).
+
+ $ref: /schemas/graph.yaml#/properties/port
+
+required:
+ - compatible
+ - in-ports
+
+additionalProperties: false
+
+examples:
+ # Minimum dummy sink definition. Dummy sink connect to coresight replicator.
+ - |
+ sink {
+ compatible = "arm,coresight-dummy-sink";
+
+ in-ports {
+ port {
+ eud_in_replicator_swao: endpoint {
+ remote-endpoint = <&replicator_swao_out_eud>;
+ };
+ };
+ };
+ };
+
+...
diff --git a/Documentation/devicetree/bindings/arm/arm,coresight-dummy-source.yaml b/Documentation/devicetree/bindings/arm/arm,coresight-dummy-source.yaml
new file mode 100644
index 000000000000..5fedaed49a1f
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/arm,coresight-dummy-source.yaml
@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: GPL-2.0-only or BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/arm,coresight-dummy-source.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM Coresight Dummy source component
+
+description: |
+ CoreSight components are compliant with the ARM CoreSight architecture
+ specification and can be connected in various topologies to suit a particular
+ SoCs tracing needs. These trace components can generally be classified as
+ sinks, links and sources. Trace data produced by one or more sources flows
+ through the intermediate links connecting the source to the currently selected
+ sink.
+
+ The Coresight dummy source component is for the specific coresight source
+ devices kernel don't have permission to access or configure. For some SOCs,
+ there would be Coresight source trace components on sub-processor which
+ are conneted to AP processor via debug bus. For these devices, a dummy driver
+ is needed to register them as Coresight source devices, so that paths can be
+ created in the driver. It provides Coresight API for operations on dummy
+ source devices, such as enabling and disabling them. It also provides the
+ Coresight dummy source paths for debugging.
+
+ The primary use case of the coresight dummy source is to build path in kernel
+ side for dummy source component.
+
+maintainers:
+ - Mike Leach <mike.leach@xxxxxxxxxx>
+ - Suzuki K Poulose <suzuki.poulose@xxxxxxx>
+ - James Clark <james.clark@xxxxxxx>
+ - Mao Jinlong <quic_jinlmao@xxxxxxxxxxx>
+ - Hao Zhang <quic_hazha@xxxxxxxxxxx>
+
+properties:
+ compatible:
+ enum:
+ - arm,coresight-dummy-source
+
+ out-ports:
+ $ref: /schemas/graph.yaml#/properties/ports
+
+ properties:
+ port:
+ description: Output connection from the source to Coresight
+ Trace bus.
+ $ref: /schemas/graph.yaml#/properties/port
+
+required:
+ - compatible
+ - out-ports
+
+additionalProperties: false
+
+examples:
+ # Minimum dummy source definition. Dummy source connect to coresight funnel.
+ - |
+ source {
+ compatible = "arm,coresight-dummy-source";
+
+ out-ports {
+ port {
+ dummy_riscv_out_funnel_swao: endpoint {
+ remote-endpoint = <&funnel_swao_in_dummy_riscv>;
+ };
+ };
+ };
+ };
+
+...
--
2.17.1