On 19/08/2024 10:51, JieGan wrote: > On Mon, Aug 19, 2024 at 08:25:33AM +0200, Krzysztof Kozlowski wrote: >> On 19/08/2024 03:49, JieGan wrote: >>> On Sun, Aug 18, 2024 at 08:28:34AM -0600, Rob Herring wrote: >>>> On Mon, Aug 12, 2024 at 10:41:39AM +0800, Jie Gan wrote: >>>>> Add binding file to specify how to define a Coresight TMC >>>>> Control Unit device in device tree. >>>>> >>>>> It is responsible for controlling the data filter function >>>>> based on the source device's Trace ID for TMC ETR device. >>>>> The trace data with that Trace id can get into ETR's buffer >>>>> while other trace data gets ignored. >>>>> >>>>> Signed-off-by: Jie Gan <quic_jiegan@xxxxxxxxxxx> >>>>> --- >>>>> .../bindings/arm/qcom,coresight-ctcu.yaml | 79 +++++++++++++++++++ >>>>> 1 file changed, 79 insertions(+) >>>>> create mode 100644 Documentation/devicetree/bindings/arm/qcom,coresight-ctcu.yaml >>>>> >>>>> diff --git a/Documentation/devicetree/bindings/arm/qcom,coresight-ctcu.yaml b/Documentation/devicetree/bindings/arm/qcom,coresight-ctcu.yaml >>>>> new file mode 100644 >>>>> index 000000000000..7a9580007942 >>>>> --- /dev/null >>>>> +++ b/Documentation/devicetree/bindings/arm/qcom,coresight-ctcu.yaml >>>>> @@ -0,0 +1,79 @@ >>>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) >>>>> +%YAML 1.2 >>>>> +--- >>>>> +$id: http://devicetree.org/schemas/arm/qcom,coresight-ctcu.yaml# >>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml# >>>>> + >>>>> +title: CoreSight TMC Control Unit >>>>> + >>>>> +maintainers: >>>>> + - Yuanfang Zhang <quic_yuanfang@xxxxxxxxxxx> >>>>> + - Mao Jinlong <quic_jinlmao@xxxxxxxxxxx> >>>>> + - Jie Gan <quic_jiegan@xxxxxxxxxxx> >>>>> + >>>>> +description: >>>>> + The Coresight TMC Control unit controls various Coresight behaviors. >>>>> + It works as a helper device when connected to TMC ETR device. >>>>> + It is responsible for controlling the data filter function based on >>>>> + the source device's Trace ID for TMC ETR device. The trace data with >>>>> + that Trace id can get into ETR's buffer while other trace data gets >>>>> + ignored. >>>> >>>> Nowhere is TMC defined. >>> The Coresight TMC control unit(CTCU) connected to Coresight TMC device via replicator and >>> works as a helper device to TMC device. >> >> Did you understand the feedback or just responding with whatever to get >> rid of reviewers? > > Sorry for the insufficient clarity in my response, I am just misunderstood the feedback and try > to explain the relationship between TMC and CTCU device. > > I will add the TMC description to explain what TMC is as shown below: > The Trace Memory Controller(TMC) is used for Embedded Trace Buffer(ETB), Embedded Trace FIFO(ETF) > and Embedded Trace Router(ETR) configurations. The configuration mode (ETB, ETF, ETR) is > discovered at boot time when the device is probed. Thanks. > >> >>> >>> The in-ports listed below illustrate their connection to TMC devices. >>> >>>> >>>>> + >>>>> +properties: >>>>> + compatible: >>>>> + enum: >>>>> + - qcom,sa8775p-ctcu >>>>> + >>>>> + reg: >>>>> + maxItems: 1 >>>>> + >>>>> + clocks: >>>>> + maxItems: 1 >>>>> + >>>>> + clock-names: >>>>> + items: >>>>> + - const: apb >>>>> + >>>>> + in-ports: >>>> >>>> Use 'ports' unless you have both in and out ports. >>> The ‘in-ports’ and ‘out-ports’ properties will be parsed by ‘of_coresight_get_port_parent’ >>> and their relationships to other devices will be stored in the coresight_platform_data structure. >>> >>> for example: >>> struct coresight_platform_data { >>> int nr_inconns; >>> int nr_outconns; >>> struct coresight_connection **out_conns; >>> struct coresight_connection **in_conns; >>> }; >>> >>> https://elixir.bootlin.com/linux/v6.11-rc4/source/drivers/hwtracing/coresight/coresight-platform.c#L147 >> >> and? If you respond with some unrelated argument, we will respond with >> the same: Use 'ports' unless you have both in and out ports. > > Sorry for the insufficient response. > > The Coresight driver prefers using ‘in-ports’ and ‘out-ports’ instead of the ‘ports’ property, as each > Coresight component needs to specify its input and output directions. > > The Coresight system operates by integrating all Coresight components and construting its data flow path > based on the defined directions. > > Consequently, the data flow direction cannot be determined when utilizing the ‘ports’ property in the > Coresight system. It can be determined. Driver knows that there are only in-ports, so you cannot have here other direction. Maybe the drivers have somehow this hard-coded? But that's a bit annoying limitation. Best regards, Krzysztof
