Re: [PATCH 1/4] arm64: dts: qcom: sc8280xp: rename i2c5 to i2c21

From: Johan Hovold <johan@kernel.org>
To: Konrad Dybcio <konrad.dybcio@linaro.org>
Cc: Brian Masney <bmasney@redhat.com>,
	andersson@kernel.org, krzysztof.kozlowski+dt@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
Date: Tue, 13 Dec 2022 16:32:43 +0100	[thread overview]
Message-ID: <Y5ibG29yKQgD54Dn@hovoldconsulting.com> (raw)
In-Reply-To: <114e960f-3b63-8c8f-9d4a-87173049d730@linaro.org>

On Tue, Dec 13, 2022 at 04:29:04PM +0100, Konrad Dybcio wrote:
> 
> 
> On 13.12.2022 16:17, Johan Hovold wrote:
> > On Tue, Dec 13, 2022 at 03:54:05PM +0100, Johan Hovold wrote:
> >> On Mon, Dec 12, 2022 at 01:23:11PM -0500, Brian Masney wrote:
> >>> According to the downstream 5.4 kernel sources for the sa8540p,
> >>> i2c@894000 is labeled i2c bus 21, not 5. The interrupts and clocks
> >>> also match. Let's go ahead and correct the name that's used in the
> >>> three files where this is listed.
> >>>
> >>> Signed-off-by: Brian Masney <bmasney@redhat.com>
> >>> Fixes: 152d1faf1e2f3 ("arm64: dts: qcom: add SC8280XP platform")
> >>> Fixes: ccd3517faf183 ("arm64: dts: qcom: sc8280xp: Add reference device")
> >>> Fixes: 32c231385ed43 ("arm64: dts: qcom: sc8280xp: add Lenovo Thinkpad X13s devicetree")
> >>
> >>> diff --git a/arch/arm64/boot/dts/qcom/sc8280xp.dtsi b/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
> >>> index 109c9d2b684d..875cc91324ce 100644
> >>> --- a/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
> >>> +++ b/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
> >>> @@ -827,7 +827,7 @@ qup2_uart17: serial@884000 {
> >>>  				status = "disabled";
> >>>  			};
> >>>  
> >>> -			qup2_i2c5: i2c@894000 {
> >>> +			qup2_i2c21: i2c@894000 {
> >>
> >> 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.
> > 
> > It appears sc8280xp is the only qcom platform using a qup prefix (even
> > if some older platform use a blsp equivalent), and we're not even using
> > it consistently as we, for example, have both
> > 
> > 	qup2_uart17, and
> > 	qup2_i2c5
> > 
> > (where the former should have been qup2_uart1).
> > 
> > So either we fix up the current labels or just drop the qup prefixes and
> > use a flat naming scheme (e.g. uart17 and i2c21).

> Oh, I didn't notice that! I suppose sticking with i2cN as we've been
> doing ever since i2c-geni was introduced sounds like the best option..

Yeah, sounds good to me.

Johan