Re: [PATCH v3 1/5] dt-bindings: usb: convert ti,hd3ss3220 bindings to json-schema

From: Wesley Cheng <wcheng@codeaurora.org>
To: Biju Das <biju.das.jz@bp.renesas.com>,
	Rob Herring <robh+dt@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@bp.renesas.com>,
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
	Heikki Krogerus <heikki.krogerus@linux.intel.com>,
	"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Chris Paterson <Chris.Paterson2@renesas.com>,
	Biju Das <biju.das@bp.renesas.com>,
	"linux-renesas-soc@vger.kernel.org" 
	<linux-renesas-soc@vger.kernel.org>
Subject: Re: [PATCH v3 1/5] dt-bindings: usb: convert ti,hd3ss3220 bindings to json-schema
Date: Fri, 2 Oct 2020 18:04:05 -0700	[thread overview]
Message-ID: <5855e79f-0f97-6f8a-2738-93424d2ed3a0@codeaurora.org> (raw)
In-Reply-To: <TYBPR01MB5309C832C9DE7B1B5E5FBCA886360@TYBPR01MB5309.jpnprd01.prod.outlook.com>

>>>
>>> Hi Biju,
>>>
>>> I'm involved in a separate thread[1] and I just wanted to get your
>>> inputs on how you understood the port and endpoint assignments for the
>>> USB type C connectors in different designs.
>>>
>>> Since the hd3ss3220 does the type C lane detect and has an integrated
>>> lane select mux, what is the ss_ep being used for?
>>
>> In our case, Type C Connector --> HS lines directly connected to SoC, where
>> as the SS lines connected  to HD3SS3220 Mux and output of mux is
>> Connected to SoC.
>>
>> This mux driver detects state change on the CC lines, reading the
>> orientation/role and communicating this information to SoC for assigning
>> roles using USB role switch framework.
>>
>> Case 1:-  Model connector node as the child node of the mux.
>>
>> The bindings for this case [1] is not complaint to typec connector bindings,
>> since it is missing port@0 node.
>> [1] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-
>> next.git/tree/Documentation/devicetree/bindings/usb/ti,hd3ss3220.txt?h=n
>> ext-20200917
>>
>> typec Connector bindings requires port@0 should be HS and port@1 should
>> be SS as per the discussion [2],  so I need to remodel connector node as
>> separate one.
>> [2] https://patchwork.kernel.org/patch/11669423/
>>
>> Case 2:-  Model connector node as a separate one based on the hardware
>> design
>>
>> Type c connector port@0  --> SoC  (hs ep) Type c connector  port@1 -->
>> connected to USB3.0 Mux -->  SoC( for usb3 role switch)
>>
>> Here the input of the Mux is connected to TypeC connector and Output of
>> the mux is connected to the SoC, which is inline with hardware design.
>> The full example of this model here [3]
>> [3] https://patchwork.kernel.org/patch/11733263/
>>
>> In both our designs, looks like, type c connector connected to SS MUX and
>> output of SS Mux is Connected to SoC for role switch. Am I missing some
>> thing?
>> So may be we need to update the connector bindings for this use case. What
>> do you think?
> 
> FYI, I have posted v4 with changes in usb connector bindings.
> 
> [1] https://patchwork.kernel.org/patch/11787677/
> [2] https://patchwork.kernel.org/patch/11787679/
> 
Hi Biju,

Great, thanks! Let me take a look :).

Thanks

Regards,
Wesley Cheng

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