Messages in this thread | | | Subject | Re: [PATCH V3 06/14] dts: bindings: Document device tree bindings for ETE | From | Suzuki K Poulose <> | Date | Wed, 10 Feb 2021 12:33:44 +0000 |
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Hi Rob
On 2/9/21 7:00 PM, Rob Herring wrote: > On Wed, Jan 27, 2021 at 02:25:30PM +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> >> --- >> Changes in V3: >> >> - Fixed all DT yaml semantics problems >> >> Documentation/devicetree/bindings/arm/ete.yaml | 74 ++++++++++++++++++++++++++ >> 1 file changed, 74 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..edc1fe2 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/arm/ete.yaml >> @@ -0,0 +1,74 @@ >> +# 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've already established 'cpus' for this purpose. >
Please see : https://lkml.kernel.org/r/9417218b-6eda-373b-a2cb-869089ffc7cd@arm.com for my response in the previous version to this and the one with out-ports.
>> + description: | >> + Handle to the cpu this ETE is bound to. >> + $ref: /schemas/types.yaml#/definitions/phandle >> + >> + out-ports: >> + type: object > > Replace with: $ref: /schemas/graph.yaml#/properties/ports
So, just to confirm again : The CoreSight graph bindings expect the input ports and output ports grouped under in-ports{} and out-ports{} respectively to avoid having to specify the direction of the ports in the individual "port" nodes. i.e
in-ports {
property: ports OR property: port
required: OneOf: ports port }
out-ports {
# same as above }
So thats why I added out-ports as a new object, where the ports/port could be a child node.
Ideally the definition of out-ports /in-ports should go to a common schema for CoreSight bindings, when we move to Yaml for the existing bindings, which will follow in a separate series, later.
> >> + description: | >> + Output connections from the ETE to legacy CoreSight trace bus. >> + properties: >> + port: >> + $ref: /schemas/graph.yaml#/properties/port > > Actually, if only 1 port ever, you can drop 'out-ports' and just have > 'port'. Not sure though if the coresight stuff depends on 'out-ports'. >
Cheers Suzuki
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