Re: [PATCH v1 1/4] dt-bindings: iio: adc: Add MediaTek MT6359 PMIC AUXADC

[Krzysztof Kozlowski <krzk@kernel.org>]

On 04/06/2024 10:55, AngeloGioacchino Del Regno wrote:
> Il 01/06/24 17:32, Krzysztof Kozlowski ha scritto:
>> On 30/05/2024 11:34, AngeloGioacchino Del Regno wrote:
>>> Add a new binding for the MT6350 Series (MT6357/8/9) PMIC AUXADC,
>>> providing various ADC channels for both internal temperatures and
>>> voltages, audio accessory detection (hp/mic/hp+mic and buttons,
>>> usually on a 3.5mm jack) other than some basic battery statistics
>>> on boards where the battery is managed by this PMIC.
>>>
>>> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
>>> ---
>>>   .../iio/adc/mediatek,mt6359-auxadc.yaml       | 43 +++++++++++++++++++
>>>   .../iio/adc/mediatek,mt6357-auxadc.h          | 21 +++++++++
>>>   .../iio/adc/mediatek,mt6358-auxadc.h          | 22 ++++++++++
>>>   .../iio/adc/mediatek,mt6359-auxadc.h          | 22 ++++++++++
>>>   4 files changed, 108 insertions(+)
>>>   create mode 100644 Documentation/devicetree/bindings/iio/adc/mediatek,mt6359-auxadc.yaml
>>>   create mode 100644 include/dt-bindings/iio/adc/mediatek,mt6357-auxadc.h
>>>   create mode 100644 include/dt-bindings/iio/adc/mediatek,mt6358-auxadc.h
>>>   create mode 100644 include/dt-bindings/iio/adc/mediatek,mt6359-auxadc.h
>>>
>>> diff --git a/Documentation/devicetree/bindings/iio/adc/mediatek,mt6359-auxadc.yaml b/Documentation/devicetree/bindings/iio/adc/mediatek,mt6359-auxadc.yaml
>>> new file mode 100644
>>> index 000000000000..dd6c331905cf
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/iio/adc/mediatek,mt6359-auxadc.yaml
>>> @@ -0,0 +1,43 @@
>>> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
>>> +%YAML 1.2
>>> +---
>>> +$id: http://devicetree.org/schemas/iio/adc/mediatek,mt6359-auxadc.yaml#
>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>> +
>>> +title: MediaTek MT6350 series PMIC AUXADC
>>> +
>>> +maintainers:
>>> +  - AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
>>> +
>>> +description:
>>> +  The Auxiliary Analog/Digital Converter (AUXADC) is an ADC found
>>> +  in some MediaTek PMICs, performing various PMIC related measurements
>>> +  such as battery and PMIC internal voltage regulators temperatures,
>>> +  accessory detection resistance (usually, for a 3.5mm audio jack)
>>> +  other than voltages for various PMIC internal components.
>>> +
>>> +properties:
>>> +  compatible:
>>> +    enum:
>>> +      - mediatek,mt6357-auxadc
>>> +      - mediatek,mt6358-auxadc
>>> +      - mediatek,mt6359-auxadc
>>> +
>>> +  "#io-channel-cells":
>>> +    const: 1
>>> +
>>> +additionalProperties: false
>>
>> If there is going to be a re-spin, please move this below required: block.
>>
> 
> Yep, will do. Fixed up for v2.
> 
>>> +
>>> +required:
>>> +  - compatible
>>> +  - "#io-channel-cells"
>>> +
>>> +examples:
>>> +  - |
>>> +    pmic {
>>> +        pmic_adc: adc {
>>> +            compatible = "mediatek,mt6359-auxadc";
>>> +            #io-channel-cells = <1>;
>>> +        };
>>
>> This suggests that you should grow (make complete) the parent PMIC example.
> 
> Uhm, should I instead add that to bindings/mfd/mediatek,mt6357.yaml and avoid
> growing the parent example?

No. You should avoid this example and grow the parent example. Not avoid
parent example...

> 
>    adc:
>      type: object
>      $ref: /schemas/iio/adc/mediatek,mt6359-auxadc.yaml
>      unevaluatedProperties: false
> 
>>
>> Actually having this as a separate node is not really needed. Why it
>> cannot be just part of the MFD/parent node?
>>
> 
> (glossary: PWRAP = PMIC [SPI] WRAPper)
> 
> The top node is the PWRAP, an IP that is (mostly) used to dispatch commands to
> the PMIC, but the AUXADC is not integrated into the PWRAP, but into the PMIC.

Eh? mediatek,mt6357.yaml says it is a PMIC...

> 
> Declaring the AUXADC as a PWRAP child would therefore be an incorrect description
> of the hardware.
> 
> P.S.: not necessary, but to "complete the circle" ... note that the PWRAP can be
>        skipped on some SoCs/firmwares/configurations, even though afaik that's only
>        mostly for debugging purposes, it's not granted that you have pwrap between
>        SoC and PMIC on all SoCs/fws/confs, even though, all of the boards that are
>        supported upstream do have it and do require it.

Best regards,
Krzysztof


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