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Date:   Tue, 13 Dec 2022 16:28:12 +0100
From:   Johan Hovold <johan@kernel.org>
To:     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, quic_shazhuss@quicinc.com
Subject: Re: [PATCH 1/4] arm64: dts: qcom: sc8280xp: rename i2c5 to i2c21
Message-ID: <Y5iaDP+nV9B59U2b@hovoldconsulting.com>
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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?

Johan