linux-kernel - Re: [PATCH v2 3/5] dt-bindings: phy: qcom,sc8280xp-qmp-usb43dp-phy: Document static lanes mapping

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <455375d4-c558-4d0e-9284-23905c8d0bac@linaro.org>
Date: Tue, 2 Sep 2025 13:59:04 +0200
From: Neil Armstrong <neil.armstrong@...aro.org>
To: Konrad Dybcio <konrad.dybcio@....qualcomm.com>,
 Andrzej Hajda <andrzej.hajda@...el.com>, Robert Foss <rfoss@...nel.org>,
 Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
 Jonas Karlman <jonas@...boo.se>, Jernej Skrabec <jernej.skrabec@...il.com>,
 Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
 Maxime Ripard <mripard@...nel.org>, Thomas Zimmermann <tzimmermann@...e.de>,
 David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>,
 Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
 Conor Dooley <conor+dt@...nel.org>, Vinod Koul <vkoul@...nel.org>,
 Kishon Vijay Abraham I <kishon@...nel.org>,
 Bjorn Andersson <andersson@...nel.org>,
 Konrad Dybcio <konradybcio@...nel.org>
Cc: dri-devel@...ts.freedesktop.org, devicetree@...r.kernel.org,
 linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org,
 linux-phy@...ts.infradead.org
Subject: Re: [PATCH v2 3/5] dt-bindings: phy: qcom,sc8280xp-qmp-usb43dp-phy:
 Document static lanes mapping

On 02/09/2025 13:50, Konrad Dybcio wrote:
> On 9/2/25 11:00 AM, Neil Armstrong wrote:
>> The QMP USB3/DP Combo PHY hosts an USB3 phy and a DP PHY on top
>> of a combo glue to route either lanes to the 4 shared physical lanes.
>>
>> The routing of the lanes can be:
>> - 2 DP + 2 USB3
>> - 4 DP
>> - 2 USB3
>>
>> The layout of the lanes was designed to be mapped and swapped
>> related to the USB-C Power Delivery negociation, so it supports
>> a finite set of mappings inherited by the USB-C Altmode layouts.
>>
>> Nevertheless those QMP Comby PHY can be statically used to
>> drive a DisplayPort connector, DP->HDMI bridge, USB3 A Connector,
>> etc... without an USB-C connector and no PD events.
>>
>> Add a property that documents the static lanes mapping to
>> each underlying PHY to allow supporting boards directly
>> connecting USB3 and DisplayPort lanes to the QMP Combo
>> lanes.
>>
>> Signed-off-by: Neil Armstrong <neil.armstrong@...aro.org>
>> ---
>>   .../phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml         | 29 ++++++++++++++++++++++
>>   1 file changed, 29 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml
>> index c8bc512df08b5694c8599f475de78679a4438449..12511a462bc6245e0b82726d053d8605148c5047 100644
>> --- a/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml
>> +++ b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml
>> @@ -76,6 +76,35 @@ properties:
>>     mode-switch: true
>>     orientation-switch: true
>>   
>> +  qcom,static-lanes-mapping:
>> +    $ref: /schemas/types.yaml#/definitions/uint32-array
>> +    minItems: 4
>> +    items:
>> +      enum:
>> +        - 0 # Unconnected (PHY_NONE)
>> +        - 4 # USB3 (PHY_TYPE_USB3)
>> +        - 6 # DisplayPort (PHY_TYPE_DP)
>> +    description:
>> +      Describes the static mapping of the Combo PHY lanes, when not used
>> +      a in a Type-C dynamic setup using USB-C PD Events to change the mapping.
>> +      The 4 lanes can either routed to the underlying DP PHY or the USB3 PHY.
>> +      Only 2 of the lanes can be connected to the USB3 PHY, but the 4 lanes can
>> +      be connected to the DP PHY.
>> +      The numbers corresponds to the PHY Type the lanes are connected to.
>> +      The possible combinations are
>> +        <0 0 0 0> when none are connected
>> +        <4 4 0 6> USB3 and DP single lane
>> +        <4 4 6 6> USB3 and DP
>> +        <6 6 4 4> DP and USB3
>> +        <6 0 4 4> DP and USB3 single lane
>> +        <4 4 0 0> USB3 Only
>> +        <0 0 4 4> USB3 Only
>> +        <6 0 0 0> DP single lane
>> +        <0 0 0 6> DP single lane
>> +        <6 6 0 0> DP 2 lanes
>> +        <0 0 6 6> DP 2 lanes
>> +        <6 6 6 6> DP 4 lanes
> 
> Would
> 
> oneOf:
>    - [0, 0, 0, 0]
>    - ...
> 
> or something similar work here?

I need to check, but I may need to do that instead:
oneOf:
   - items:
       - 0
       - 0
       - 0
       - 0
   - items:
       - 4
       - 4
       - 6
       - 6
...

But I want to be extra sure this is the right path before

Neil

> 
> Konrad