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Message-ID: <15611981-19b3-5124-83da-7f9a699ef62f@linaro.org>
Date:   Mon, 26 Sep 2022 17:32:54 +0200
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Subject: Re: [PATCH] ARM: dts: qcom-pma8084: fix vadc channel node names
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To:     Luca Weiss <luca@z3ntu.xyz>, linux-arm-msm@vger.kernel.org,
        neil.armstrong@linaro.org
Cc:     ~postmarketos/upstreaming@lists.sr.ht, phone-devel@vger.kernel.org,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@somainline.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20220925202143.123208-1-luca@z3ntu.xyz>
 <98960452-9f48-7b4d-9aa6-55c0002ad1b4@linaro.org> <2647127.mvXUDI8C0e@g550jk>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <2647127.mvXUDI8C0e@g550jk>
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On 26/09/2022 16:57, Luca Weiss wrote:
> Hi Neil,
> 
> On Montag, 26. September 2022 10:27:54 CEST Neil Armstrong wrote:
>> On 25/09/2022 22:21, Luca Weiss wrote:
>>> Node names for the channel are supposed to be adc-chan@REG.
>>>
>>> Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
>>> ---
>>>
>>>   arch/arm/boot/dts/qcom-pma8084.dtsi | 17 +++++++++++------
>>>   1 file changed, 11 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/arch/arm/boot/dts/qcom-pma8084.dtsi
>>> b/arch/arm/boot/dts/qcom-pma8084.dtsi index e77602e9f95c..7ad573c7b4ac
>>> 100644
>>> --- a/arch/arm/boot/dts/qcom-pma8084.dtsi
>>> +++ b/arch/arm/boot/dts/qcom-pma8084.dtsi
>>> @@ -64,22 +64,27 @@ pma8084_vadc: adc@3100 {
>>>
>>>   			#size-cells = <0>;
>>>   			#io-channel-cells = <1>;
>>>
>>> -			die_temp {
>>> +			adc-chan@8 {
>>>
>>>   				reg = <VADC_DIE_TEMP>;
>>>   			
>>>   			};
>>>
>>> -			ref_625mv {
>>> +
>>> +			adc-chan@9 {
>>>
>>>   				reg = <VADC_REF_625MV>;
>>>   			
>>>   			};
>>>
>>> -			ref_1250v {
>>> +
>>> +			adc-chan@10 {
>>>
>>>   				reg = <VADC_REF_1250MV>;
>>>   			
>>>   			};
>>>
>>> -			ref_buf_625mv {
>>> +
>>> +			adc-chan@12 {
>>>
>>>   				reg = <VADC_SPARE1>;
>>>   			
>>>   			};
>>>
>>> -			ref_gnd {
>>> +
>>> +			adc-chan@14 {
>>>
>>>   				reg = <VADC_GND_REF>;
>>>   			
>>>   			};
>>>
>>> -			ref_vdd {
>>> +
>>> +			adc-chan@15 {
>>>
>>>   				reg = <VADC_VDD_VADC>;
>>>   			
>>>   			};
>>>   		
>>>   		};
>>
>> I don't see where this is required, bindings doesn't mandate this naming:
>>
>> patternProperties:
>>
>>     "^.*@[0-9a-f]+$":
> 
> They don't require the "adc-chan" part (although dt nodes are supposed to have 
> common names and adc-chan is used for adc for that; and dt node names are not 
> supposed to have underscores), but this validation error happens without this 
> commit:
> 
> <snip>/arch/arm/boot/dts/qcom-apq8084-ifc6540.dtb: pma8084@0: adc@3100: 
> 'oneOf' conditional failed, one must be fixed:
>         '#address-cells', '#size-cells', 'die_temp', 'ref_1250v', 'ref_625mv', 
> 'ref_buf_625mv', 'ref_gnd', 'ref_vdd' do not match any of the regexes: 
> 'pinctrl-[0-9]+'
>         'die_temp', 'ref_1250v', 'ref_625mv', 'ref_buf_625mv', 'ref_gnd', 
> 'ref_vdd' do not match any of the regexes: '^.*@[0-9a-f]+$', 'pinctrl-[0-9]+'
>         'qcom,spmi-iadc' was expected
>         From schema: <snip>/Documentation/devicetree/bindings/mfd/qcom,spmi-
> pmic.yaml
> 
> So while e.g. ref-vdd@15 would also work, adc-chan@15 is more correct.

The commit msg is not precise here. What the nodes are missing is unit
address (required by VADC bindings) and replace of underscore (coding
style). I think bindings do not require the adc-chan and we could apply
here rule from DT spec that node name should reflect it's
purpose/function, so die-temp@xxxx could be fine. Other places use
already adc-chan, so consistency could be an argument. But anyway commit
msg is not really describing why you are doing this.

Best regards,
Krzysztof