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Message-ID: <03252ccd-e200-a112-b4dd-ba9fbf25c480@quicinc.com>
Date:   Tue, 13 Dec 2022 21:04:39 +0530
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Subject: Re: [PATCH 1/4] arm64: dts: qcom: sc8280xp: rename i2c5 to i2c21
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To:     Johan Hovold <johan@kernel.org>, Brian Masney <bmasney@redhat.com>
CC:     <andersson@kernel.org>, <krzysztof.kozlowski+dt@linaro.org>,
        <konrad.dybcio@linaro.org>, <robh+dt@kernel.org>,
        <johan+linaro@kernel.org>, <linux-arm-msm@vger.kernel.org>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <ahalaney@redhat.com>, <echanude@redhat.com>
References: <20221212182314.1902632-1-bmasney@redhat.com>
 <20221212182314.1902632-2-bmasney@redhat.com>
 <Y5iSDehp72mQPc+h@hovoldconsulting.com> <Y5iWeTk2zOp9rInx@x1>
 <Y5iaDP+nV9B59U2b@hovoldconsulting.com>
From:   Shazad Hussain <quic_shazhuss@quicinc.com>
In-Reply-To: <Y5iaDP+nV9B59U2b@hovoldconsulting.com>
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On 12/13/2022 8:58 PM, Johan Hovold wrote:
> On Tue, Dec 13, 2022 at 10:12:57AM -0500, Brian Masney wrote:
>> On Tue, Dec 13, 2022 at 03:54:05PM +0100, Johan Hovold wrote:
>>> Note that the node is labelled qup2_i2c5 and not qup_i2c5.
>>>
>>> That is, the QUP nodes are labelled using two indices, and specifically
>>>
>>> 	qup2_i2c5
>>>
>>> would be another name for
>>>
>>> 	qup_i2c21
>>>
>>> if we'd been using such a flat naming scheme (there are 8 engines per
>>> QUP).
>>>
>>> So there's nothing wrong with how these nodes are currently named, but
>>> mixing the two scheme as you are suggesting would not be correct.
>>
>> Hi Johan,
>>
>> What would I use for the name in the aliases section? Right now I have:
>>
>>      aliases {
>>          i2c18 = &qup2_i2c18;
>>      }
>>
>> So qup2_i2c18 becomes qup2_i2c2. Would I use the flat naming scheme for
>> the alias like so?
>>
>>      aliases {
>>          i2c18 = &qup2_i2c2;
>>      }
> 
> Or perhaps the i2c controllers should use a zero-based index instead of
> being named after the serial engines (e.g. as we do for the console
> uart).
> 
> How are they named in the schematics?
> 

We should use from 0 to N.

Shazad

> Johan