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Date:   Tue, 12 Apr 2022 16:59:55 -0700
From:   Matthias Kaehlcke <mka@chromium.org>
To:     Srinivasa Rao Mandadapu <quic_srivasam@quicinc.com>
Cc:     agross@kernel.org, bjorn.andersson@linaro.org, robh+dt@kernel.org,
        linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, quic_rohkumar@quicinc.com,
        srinivas.kandagatla@linaro.org, dianders@chromium.org,
        swboyd@chromium.org, judyhsiao@chromium.org,
        Venkata Prasad Potturu <quic_potturu@quicinc.com>
Subject: Re: [PATCH v7 2/2] arm64: dts: qcom: sc7280: add lpass lpi pin
 controller node
Message-ID: <YlYSe5/wm06oTJej@google.com>
References: <1649685184-8448-1-git-send-email-quic_srivasam@quicinc.com>
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 <YlSCWC47tITuW/BZ@google.com>
 <9bacee6d-ab44-2975-c523-38164d016af5@quicinc.com>
 <be8c6dae-20b1-3ba1-db3f-119da1e4ebfe@quicinc.com>
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On Tue, Apr 12, 2022 at 06:41:25PM +0530, Srinivasa Rao Mandadapu wrote:
> 
> On 4/12/2022 6:18 PM, Srinivasa Rao Mandadapu wrote:
> > 
> > On 4/12/2022 1:02 AM, Matthias Kaehlcke wrote:
> > Thanks for your time Matthias!!!
> > > On Mon, Apr 11, 2022 at 07:23:04PM +0530, Srinivasa Rao Mandadapu wrote:
> > > > Add LPASS LPI pinctrl node required for Audio functionality on sc7280
> > > > based platforms.
> > > > 
> > > > Signed-off-by: Srinivasa Rao Mandadapu <quic_srivasam@quicinc.com>
> > > > Co-developed-by: Venkata Prasad Potturu <quic_potturu@quicinc.com>
> > > > Signed-off-by: Venkata Prasad Potturu <quic_potturu@quicinc.com>
> > > > ---
> > > >   arch/arm64/boot/dts/qcom/sc7280-idp.dtsi |  84
> > > > ++++++++++++++++++++++++
> > > >   arch/arm64/boot/dts/qcom/sc7280.dtsi     | 107
> > > > +++++++++++++++++++++++++++++++
> > > >   2 files changed, 191 insertions(+)
> > > > 
> > > > diff --git a/arch/arm64/boot/dts/qcom/sc7280-idp.dtsi
> > > > b/arch/arm64/boot/dts/qcom/sc7280-idp.dtsi
> > > > index 4ba2274..ea751dc 100644
> > > > --- a/arch/arm64/boot/dts/qcom/sc7280-idp.dtsi
> > > > +++ b/arch/arm64/boot/dts/qcom/sc7280-idp.dtsi
> > > > @@ -238,6 +238,90 @@
> > > >       modem-init;
> > > >   };
> > > >   +&dmic01 {
> > > Shouldn't these nodes be in the PINCTRL section at their respective
> > > positions in alphabetical order?
> > 
> > These are not part of tlmm pin control section. These are part of
> > lpass_tlmm section.
> > 
> > In your previous comment you asked to remove &lpass_tlmm. Hence brought
> > out.
> > 
> > > 
> > > nit: since you are keeping the groups the group names are a bit
> > > generic IMO.
> > > e.g. it is fairly obvious that 'dmic01_clk' refers to a clock pin,
> > > however
> > > just 'dmic01' is a bit vague. You could consider adding the prefix
> > > 'lpass_'
> > > to the group names for more clarity.
> > as dmic01 has both clk and data section, I don't think keeping clk is
> > appropriate here.
> 
> As these nodes are part of SC7280, i.e. qcom specific chipset, I feel lpass_
> is redundant.

It helps to provide some context about the pins which might not be evident
from their short names like 'dmic01' or 'rx_swr'. A nice side effect is that
the pins/groups would grouped automatically together in alphabetic ordering.

In terms of 'redundancy' it is similar to 'qup_' prefix for the I2C/SPI/UART
pins.

> If we add lpass_ to all dmic nodes, some node names are too lengthy.

The longest would be like 'lpass_dmic01_sleep' or 'lpass_rx_swr_sleep', which
doesn't seem outrageous.

In any case it's not super important. If it bothers someone enough later
on they can always send a patch that changes it.