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Message-ID: <0b091595-1587-421d-bb00-c00ef729d143@linaro.org>
Date: Fri, 22 Mar 2024 15:23:21 +0000
From: Bryan O'Donoghue <bryan.odonoghue@...aro.org>
To: neil.armstrong@...aro.org, Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
Cc: Bjorn Andersson <andersson@...nel.org>,
Konrad Dybcio <konrad.dybcio@...aro.org>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Rob Herring <robh@...nel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
Conor Dooley <conor+dt@...nel.org>, linux-arm-msm@...r.kernel.org,
linux-usb@...r.kernel.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] dt-bindings: usb: qcom,pmic-typec: drop port
description
On 22/03/2024 15:09, neil.armstrong@...aro.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
CC1/CC2
Then we would not be abusing HS/SS/SBU for the port names - we'd be
extending the connector definition but also naming the ports/endpoints
appropriately associated with the data over the hw
---
bod
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