Received-SPF: pass (google.com: domain of linux-kernel+bounces-111978-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Precedence: bulk
MIME-Version: 1.0
References: <20240322-typec-fix-example-v1-0-6b01c347419e@linaro.org>
 <20240322-typec-fix-example-v1-1-6b01c347419e@linaro.org> <230eab52-9751-43fd-8e47-fbfe12410e44@linaro.org>
 <CAA8EJprD3fM966pLV4QXPUu=bFTn24fvPMKOaGqtqkAbdz7sOQ@mail.gmail.com>
 <5ea4a187-1971-4970-a289-826d96c0351a@linaro.org> <c0f1e898-7638-4b7b-a938-9e31e5b57e57@linaro.org>
 <0b091595-1587-421d-bb00-c00ef729d143@linaro.org> <CAA8EJpqvwhafFoD_=GO4E93JBQA2A+xY0rG14pgPm=xgJ9Yz_Q@mail.gmail.com>
 <20240322183614.GA1233803-robh@kernel.org>
In-Reply-To: <20240322183614.GA1233803-robh@kernel.org>
From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Date: Fri, 22 Mar 2024 21:08:18 +0200
Message-ID: <CAA8EJppgbsa3bmCo5jbWZW7FgUtyBFS_0zBfvcRjuvjLdv7YkQ@mail.gmail.com>
Subject: Re: [PATCH 1/2] dt-bindings: usb: qcom,pmic-typec: drop port description
To: Rob Herring <robh@kernel.org>
Cc: "Bryan O'Donoghue" <bryan.odonoghue@linaro.org>, neil.armstrong@linaro.org, 
	Bjorn Andersson <andersson@kernel.org>, Konrad Dybcio <konrad.dybcio@linaro.org>, 
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>, 
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, Conor Dooley <conor+dt@kernel.org>, 
	linux-arm-msm@vger.kernel.org, linux-usb@vger.kernel.org, 
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"

On Fri, 22 Mar 2024 at 20:36, Rob Herring <robh@kernel.org> wrote:
>
> On Fri, Mar 22, 2024 at 05:49:00PM +0200, Dmitry Baryshkov wrote:
> > On Fri, 22 Mar 2024 at 17:23, Bryan O'Donoghue
> > <bryan.odonoghue@linaro.org> wrote:
> > >
> > > On 22/03/2024 15:09, neil.armstrong@linaro.org wrote:
> > > >> TBH I think we should drop this HS, SS stuff from the connector
> > > >> definition - there's nothing to say in a h/w definition anywhere HS
> > > >> must be a port or indeed SS - not all hardware knows or cares about
> > > >> different HS/SS signalling.
> > > >
> > > > It matches the USB-C connector electrical characteristics, which by spec
> > > > has, at least:
> > > > - High-Speed USB Line
> > > > - up to 4 differential high-speed lanes that can be switched to DP, USB2
> > > > or PCIe
> > > > - SideBand line (SBU)
> > > >
> > > > And those 3 components can be handled by 3 different HW in the SoC, so
> > > > each one has a dedicated port.
> > > >
> > > > Remember DT describes the HW, not the SW implementation.
> > > >
> > > > Neil
> > >
> > > Yes, you're right about that.
> > >
> > > I suppose
> > >
> > > 1. Orientation switches should be defined as coming from a port on the
> > >     connector associated with the CC pins.
> > >     port@3:
> > >     orientation-switch port name goes here
> > >
> > > 2. Data-role switches...
> > >     Again the CC pins
> > >
> > > https://community.silabs.com/s/article/what-s-the-role-of-cc-pin-in-type-c-solution?language=en_US
> > >
> > > Maybe the right-thing-to-do is to add another port for the CC pins -
> > > which would still describe the hardware characteristics but would
> > > _accurately_ name the thing which does the data-role/orientation switching
> >
> > It's true that we don't describe CC lines. However In most of the
> > cases CC lines are handled by the Type-C port manager directly. So
> > there will be a connection from usb-c-connector to the pmic-typec
> > itself (which looks pretty redundant).
>
> The thought at the time this was designed was that would be the parent
> node of the connector. That's perhaps too simple.

Yep. In both our cases the TCPM is a parent of the usb-c-connector.


-- 
With best wishes
Dmitry