Hi Rob
On 1/25/21 7:22 PM, Rob Herring wrote:
On Wed, Jan 13, 2021 at 09:48:13AM +0530, Anshuman Khandual wrote:
From: Suzuki K Poulose suzuki.poulose@arm.com
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 Cc: Rob Herring robh@kernel.org Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com Signed-off-by: Anshuman Khandual anshuman.khandual@arm.com
Documentation/devicetree/bindings/arm/ete.yaml | 71 ++++++++++++++++++++++++++ 1 file changed, 71 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 0000000..00e6a77 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/ete.yaml @@ -0,0 +1,71 @@ +# 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:
We use 'cpus' in a couple of other places, let's do that here for consistency.
This is following the existing CoreSight bindings for ETM. The same driver probes both. Also there can only ever be a single CPU for ete/etm. So, we would prefer to keep it aligned with the existing bindings to avoid causing confusion.
- description: |
Handle to the cpu this ETE is bound to.- $ref: /schemas/types.yaml#/definitions/phandle
- out-ports:
- description: |
Out put connections from the ETE to legacy CoreSight trace bus.Output
Will fix.
- $ref: /schemas/graph.yaml#/properties/ports
You have to define what each 'port' is if there can be more than 1. If there's only ever 1 then you just need 'port' though maybe all the coresight bindings require 'out-ports'. And the port nodes need a $ref to '/schemas/graph.yaml#/properties/port'.
All CoreSight components require an out-ports and/or in-ports. The ETM/ETE always has one port, but must be under out-ports in line with the CoreSight bindings.
Does this look more apt:
out-ports: description: | Output connection from the ETE to legacy CoreSight trace bus. poperties: port: $ref: /schemas/graph.yaml#/properties/port
Suzuki