On 20/08/2024 08:36, JieGan wrote: > On Mon, Aug 19, 2024 at 11:51:41AM +0200, Krzysztof Kozlowski wrote: >> 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. >> > In Coresight platform driver, the of_coresight_get_port_parent function is used to retrieve the parent of the 'ports' node. > The function is specifically hard-coded to recognize 'in-ports' and 'out-ports'. I think that's the limitation for > 'ports' property. > > https://elixir.bootlin.com/linux/v6.11-rc4/source/drivers/hwtracing/coresight/coresight-platform.c#L147 That's a limitation of coresight platform driver, not bindings. Fix your drivers. Best regards, Krzysztof
