Re: [PATCH 05/13] dt-bindings: perf: stm32: introduce DDRPERFM dt-bindings

[Clement LE GOFFIC <clement.legoffic@foss.st.com>]

On 6/23/25 11:48, Krzysztof Kozlowski wrote:
> On 23/06/2025 11:27, Clément Le Goffic wrote:
>> DDRPERFM is the DDR Performance Monitor embedded in STM32MPU SoC.
>> It allows to monitor DDR events that come from the DDR Controller
>> such as read or write events.
>>
> 
> A nit, subject: drop second/last, redundant "bindings". The
> "dt-bindings" prefix is already stating that these are bindings.
> See also:
> https://elixir.bootlin.com/linux/v6.7-rc8/source/Documentation/devicetree/bindings/submitting-patches.rst#L18
Oops, you're right thank you

>> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
>> ---
>>   .../devicetree/bindings/perf/st,stm32-ddr-pmu.yaml | 93 ++++++++++++++++++++++
>>   1 file changed, 93 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/perf/st,stm32-ddr-pmu.yaml b/Documentation/devicetree/bindings/perf/st,stm32-ddr-pmu.yaml
>> new file mode 100644
>> index 000000000000..35d34782865b
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/perf/st,stm32-ddr-pmu.yaml
>> @@ -0,0 +1,93 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/perf/st,stm32-ddr-pmu.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +maintainers:
>> +  - Clément Le Goffic <clement.legoffic@foss.st.com>
>> +
>> +title: STMicroelectronics STM32 DDR Performance Monitor (DDRPERFM)
>> +
>> +properties:
>> +  compatible:
>> +    enum:
>> +      - st,stm32mp131-ddr-pmu
>> +      - st,stm32mp151-ddr-pmu
> 
> These are compatible, aren't they?

Yes they are

>> +      - st,stm32mp251-ddr-pmu
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  clocks:
>> +    description: Reference clock for the DDR Performance Monitor
> 
> Drop description, obvious.

Ok

> 
>> +    maxItems: 1
>> +
>> +  resets:
>> +    description: Reset control for the DDR Performance Monitor
> 
> Drop description, obvious.

Ok

> 
> 
>> +    maxItems: 1
>> +
>> +  access-controllers:
>> +    minItems: 1
>> +    maxItems: 2
>> +
>> +  st,dram-type:
>> +    description: |
>> +      This property is used to specify the type of DRAM memory connected to the
>> +      associated memory controller. It is required for the DDR Performance Monitor
>> +      to correctly interpret the performance data.
>> +      0 = LPDDR4,
>> +      1 = LPDDR3,
>> +      2 = DDR4,
>> +      3 = DDR3
>> +    $ref: /schemas/types.yaml#/definitions/uint32
> 
> No, use standard JEDEC memory bindings (memory controllers) if you need
> to describe the memory, otherwise you duplicate that binding and
> duplicate the memory information.

Ok didn't know about it, I'll take a look

Best regard,
Clément

>> +    enum: [0, 1, 2, 3]
>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +
>> +allOf:
>> +  - if:
>> +      properties:
>> +        compatible:
>> +          contains:
>> +            enum:
>> +              - st,stm32mp131-ddr-pmu
>> +              - st,stm32mp151-ddr-pmu
>> +    then:
>> +      required:
>> +        - clocks
>> +        - resets
>> +
>> +  - if:
>> +      properties:
>> +        compatible:
>> +          contains:
>> +            const: st,stm32mp251-ddr-pmu
>> +    then:
>> +      required:
>> +        - access-controllers
>> +        - st,dram-type
>> +
>> +additionalProperties: false
> Best regards,
> Krzysztof