Messages in this thread | | | Subject | Re: [PATCH V2 06/11] dts: bindings: Document device tree bindings for ETE | From | Suzuki K Poulose <> | Date | Mon, 25 Jan 2021 23:28:10 +0000 |
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On 1/25/21 10:20 PM, Suzuki K Poulose wrote: > 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
Correction, the above should be :
+ out-ports: + type: object + description: | + Output connections from the ETE to legacy CoreSight trace bus. + properties: + port: + $ref: /schemas/graph.yaml#/properties/port
That works fine for me. Does that look fine ? Some day, we should convert the coresight dt bindings to yaml and import the out-ports/in-ports from the scheme :-)
Cheers Suzuki
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