Document the device tree bindings for Embedded Trace Extensions. ETE can be connected to legacy coresight components and thus could optionally contain a connection graph as described by the CoreSight bindings.
Cc: devicetree@vger.kernel.org Cc: Mathieu Poirier mathieu.poirier@linaro.org Cc: Mike Leach mike.leach@linaro.org Reviewed-by: Rob Herring robh@kernel.org Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com --- .../devicetree/bindings/arm/ete.yaml | 75 +++++++++++++++++++ MAINTAINERS | 1 + 2 files changed, 76 insertions(+) create mode 100644 Documentation/devicetree/bindings/arm/ete.yaml
diff --git a/Documentation/devicetree/bindings/arm/ete.yaml b/Documentation/devicetree/bindings/arm/ete.yaml new file mode 100644 index 000000000000..7f9b2d1e1147 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/ete.yaml @@ -0,0 +1,75 @@ +# SPDX-License-Identifier: GPL-2.0-only or BSD-2-Clause +# Copyright 2021, Arm Ltd +%YAML 1.2 +--- +$id: "http://devicetree.org/schemas/arm/ete.yaml#" +$schema: "http://devicetree.org/meta-schemas/core.yaml#" + +title: ARM Embedded Trace Extensions + +maintainers: + - Suzuki K Poulose suzuki.poulose@arm.com + - Mathieu Poirier mathieu.poirier@linaro.org + +description: | + Arm Embedded Trace Extension(ETE) is a per CPU trace component that + allows tracing the CPU execution. It overlaps with the CoreSight ETMv4 + architecture and has extended support for future architecture changes. + The trace generated by the ETE could be stored via legacy CoreSight + components (e.g, TMC-ETR) or other means (e.g, using a per CPU buffer + Arm Trace Buffer Extension (TRBE)). Since the ETE can be connected to + legacy CoreSight components, a node must be listed per instance, along + with any optional connection graph as per the coresight bindings. + See bindings/arm/coresight.txt. + +properties: + $nodename: + pattern: "^ete([0-9a-f]+)$" + compatible: + items: + - const: arm,embedded-trace-extension + + cpu: + description: | + Handle to the cpu this ETE is bound to. + $ref: /schemas/types.yaml#/definitions/phandle + + out-ports: + description: | + Output connections from the ETE to legacy CoreSight trace bus. + $ref: /schemas/graph.yaml#/properties/ports + properties: + port: + description: Output connection from the ETE to legacy CoreSight Trace bus. + $ref: /schemas/graph.yaml#/properties/port + +required: + - compatible + - cpu + +additionalProperties: false + +examples: + +# An ETE node without legacy CoreSight connections + - | + ete0 { + compatible = "arm,embedded-trace-extension"; + cpu = <&cpu_0>; + }; +# An ETE node with legacy CoreSight connections + - | + ete1 { + compatible = "arm,embedded-trace-extension"; + cpu = <&cpu_1>; + + out-ports { /* legacy coresight connection */ + port { + ete1_out_port: endpoint { + remote-endpoint = <&funnel_in_port0>; + }; + }; + }; + }; + +... diff --git a/MAINTAINERS b/MAINTAINERS index aa84121c5611..2a20a36c724a 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1761,6 +1761,7 @@ F: Documentation/ABI/testing/sysfs-bus-coresight-devices-* F: Documentation/devicetree/bindings/arm/coresight-cpu-debug.txt F: Documentation/devicetree/bindings/arm/coresight-cti.yaml F: Documentation/devicetree/bindings/arm/coresight.txt +F: Documentation/devicetree/bindings/arm/ete.yaml F: Documentation/trace/coresight/* F: drivers/hwtracing/coresight/* F: include/dt-bindings/arm/coresight-cti-dt.h