Messages in this thread | | | Subject | Re: [PATCH V3 06/14] dts: bindings: Document device tree bindings for ETE | From | Suzuki K Poulose <> | Date | Thu, 18 Feb 2021 22:51:56 +0000 |
| |
On 2/18/21 6:33 PM, Rob Herring wrote: > On Wed, Feb 10, 2021 at 12:33:44PM +0000, Suzuki K Poulose wrote: >> 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. > > Okay, fair enough. > >> >>>> + 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 > > No, 'ports' as a child of in-ports is not correct. There should only be > 'port(@[0-9a-f]+)?' nodes. That's why you need the above $ref added. The > $ref doesn't define the node name is 'ports', but what a 'ports' or > 'foo-ports' contains.
Sorry, it is my bad. We don't expect ports{} under in-ports. So your suggestion is the accurate one. I will respin.
> >> } >> >> 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. > > Yes, maybe, but I'm not sure something common is going to help here. > You'll still have to describe what each 'port' node does in each device > specific binding.
For CoreSight components the end-point of the ports are system specific. i.e, it could be anything on the other end. There is no fixed end-point connection.
e.g, ETM could be connected to a Replicator or a Funnel. Same as here above for ETE. Thus the driver must parse the endpoints and make the connection path from devices to other devices.
Anyways, will come to that in a different series.
I will fix the in-ports/out-ports for the next version.
Thanks for your guidance.
Cheers Suzuki
> > Rob >
| |