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Message-ID: <e71a38a9-7a92-4156-a7f0-52f71d461d61@collabora.com>
Date: Mon, 10 Jun 2024 10:00:55 +0200
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Subject: Re: [PATCH v2 1/5] dt-bindings: iio: adc: Add MediaTek MT6359 PMIC
 AUXADC
To: Rob Herring <robh@kernel.org>
Cc: jic23@kernel.org, lars@metafoo.de, krzk+dt@kernel.org,
 conor+dt@kernel.org, matthias.bgg@gmail.com, lee@kernel.org,
 andy@kernel.org, nuno.sa@analog.com, bigunclemax@gmail.com,
 dlechner@baylibre.com, marius.cristea@microchip.com,
 marcelo.schmitt@analog.com, fr0st61te@gmail.com, mitrutzceclan@gmail.com,
 mike.looijmans@topic.nl, marcus.folkesson@gmail.com,
 linux-iio@vger.kernel.org, devicetree@vger.kernel.org,
 linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
 linux-mediatek@lists.infradead.org, andy.shevchenko@gmail.com,
 kernel@collabora.com
References: <20240604123008.327424-1-angelogioacchino.delregno@collabora.com>
 <20240604123008.327424-2-angelogioacchino.delregno@collabora.com>
 <20240605235239.GA3455504-robh@kernel.org>
From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
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In-Reply-To: <20240605235239.GA3455504-robh@kernel.org>
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Il 06/06/24 01:52, Rob Herring ha scritto:
> On Tue, Jun 04, 2024 at 02:30:04PM +0200, 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.
>>
>> Also add the necessary dt-binding headers for devicetree consumers.
>>
>> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
>> ---
>>   .../iio/adc/mediatek,mt6359-auxadc.yaml       | 33 +++++++++++++++++++
>>   .../iio/adc/mediatek,mt6357-auxadc.h          | 21 ++++++++++++
>>   .../iio/adc/mediatek,mt6358-auxadc.h          | 22 +++++++++++++
>>   .../iio/adc/mediatek,mt6359-auxadc.h          | 22 +++++++++++++
>>   4 files changed, 98 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..6497c416094d
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/iio/adc/mediatek,mt6359-auxadc.yaml
>> @@ -0,0 +1,33 @@
>> +# 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
> 
> Why do you need a node here? Just add #io-channel-cells to the parent
> node.
> 

Because some boards will want to avoid probing the related driver, as that will
trigger a reset and this may not play well with ECs (namely, some Chromebooks),
which are reading the same AUXADC block.

If I avoid using a new node, instead of just using `status`, I'll have to add a
"mediatek,disable-auxadc" property to the parent node, which isn't pretty...

Cheers,
Angelo

>> +
>> +required:
>> +  - compatible
>> +  - "#io-channel-cells"
>> +
>> +additionalProperties: false