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Date: Tue, 6 Feb 2024 18:09:58 -0600
From: Andrew Halaney <ahalaney@redhat.com>
To: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: neil.armstrong@linaro.org, 
	Krishna Kurapati <quic_kriskura@quicinc.com>, Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, 
	Rob Herring <robh+dt@kernel.org>, Bjorn Andersson <andersson@kernel.org>, 
	Konrad Dybcio <konrad.dybcio@linaro.org>, Conor Dooley <conor+dt@kernel.org>, linux-kernel@vger.kernel.org, 
	linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, quic_ppratap@quicinc.com, 
	quic_jackp@quicinc.com
Subject: Re: Re: [PATCH 3/3] arm64: dts: qcom: sa8540-ride: Enable first port
 of tertiary usb controller
Message-ID: <6q2ocvrujbli42rjddflyol74xianr7j47jwcgdnnmwjanv25d@uw2da7zulqqd>
References: <20240206114745.1388491-1-quic_kriskura@quicinc.com>
 <20240206114745.1388491-4-quic_kriskura@quicinc.com>
 <23824242-1b37-4544-ae9a-0a5a0582580e@linaro.org>
 <CAA8EJpqbXvKMQktGsxMFJnR+fXoOz8hFmm+E3ROPTjjiD0QLvg@mail.gmail.com>
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On Tue, Feb 06, 2024 at 03:30:32PM +0200, Dmitry Baryshkov wrote:
> On Tue, 6 Feb 2024 at 15:28, <neil.armstrong@linaro.org> wrote:
> >
> > On 06/02/2024 12:47, Krishna Kurapati wrote:
> > > From: Andrew Halaney <ahalaney@redhat.com>
> > >
> > > There is now support for the multiport USB controller this uses so
> > > enable it.
> > >
> > > The board only has a single port hooked up (despite it being wired up to
> > > the multiport IP on the SoC). There's also a USB 2.0 mux hooked up,
> > > which by default on boot is selected to mux properly. Grab the gpio
> > > controlling that and ensure it stays in the right position so USB 2.0
> > > continues to be routed from the external port to the SoC.
> 
> What is connected to the other port of the MUX?

/me blows off the dust on the schematic

It's a 1:2 mux, and one option is the out the board, the other
is a test point I believe if I'm reading things right, although its not
labeled so I'm not sure anyone would actually find it on the board.

> 
> > >
> > > Signed-off-by: Andrew Halaney <ahalaney@redhat.com>
> > > Co-developed-by: Krishna Kurapati <quic_kriskura@quicinc.com>
> > > Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
> > > ---
> > >   arch/arm64/boot/dts/qcom/sa8540p-ride.dts | 21 +++++++++++++++++++++
> > >   1 file changed, 21 insertions(+)
> > >
> > > diff --git a/arch/arm64/boot/dts/qcom/sa8540p-ride.dts b/arch/arm64/boot/dts/qcom/sa8540p-ride.dts
> > > index b04f72ec097c..eed1ddc29bc1 100644
> > > --- a/arch/arm64/boot/dts/qcom/sa8540p-ride.dts
> > > +++ b/arch/arm64/boot/dts/qcom/sa8540p-ride.dts
> > > @@ -503,6 +503,18 @@ &usb_2_qmpphy0 {
> > >       status = "okay";
> > >   };
> > >
> > > +&usb_2 {
> > > +     pinctrl-0 = <&usb2_en>;
> > > +     pinctrl-names = "default";
> > > +
> > > +     status = "okay";
> > > +};
> > > +
> > > +&usb_2_dwc3 {
> > > +     phy-names = "usb2-port0", "usb3-port0";
> > > +     phys = <&usb_2_hsphy0>, <&usb_2_qmpphy0>;
> > > +};
> > > +
> > >   &xo_board_clk {
> > >       clock-frequency = <38400000>;
> > >   };
> > > @@ -655,4 +667,13 @@ wake-pins {
> > >                       bias-pull-up;
> > >               };
> > >       };
> > > +
> > > +     usb2_en: usb2-en-state {
> > > +             /* TS3USB221A USB2.0 mux select */
> > > +             pins = "gpio24";
> > > +             function = "gpio";
> > > +             drive-strength = <2>;
> > > +             bias-disable;
> > > +             output-low;
> > > +     };
> > >   };
> >
> > Isn't gpio-hog the preferred way to describe that ?
> 
> That depends. As this pinctrl describes board configuration, I'd agree
> with Neil.

I unfortunately don't have the experience with gpio-hog to weigh in
here, but wouldn't be opposed to Krishna switching it if that's what's
recommended for this type of thing.

> 
> 
> -- 
> With best wishes
> Dmitry
>