From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELuQOWdyJQhxz7iGTV6jVcvDGk7HRFvqo/YXKXWlveko/S9UxJh3TxBWJZw4HmeOAIfBm69o ARC-Seal: i=1; a=rsa-sha256; t=1521133725; cv=none; d=google.com; s=arc-20160816; b=cU1LE/yetXmeeioHb6MbtjOtmKOQFZO4D1Kkl8hWQyv+B1dVt39Iiz5btRnh7sQ32Z ZEp+VfnMMVcH+Tqjh+StHzItTES5Speg7Nq21IqEJxJysbTpND3dP5KFDGd8HM6knRUL LsCBxDaCiHlcHtLVueAKgcrAws0dmZ6aZ8qQarfxX3MltXFILUZSrNQnqDP9e8HwB9k2 PhOVsCAWdnwhouJb6tRC3Nck0G4oktNNWRSvo7FEfVXEf3JAeKH0NJIG0Tk1DPB7/43f ILR5hOrowoZmQUirBu1QYHLWRP7QVSOFLb/eknUMsL8+cnQUSSVycUavM4igTIi3eQVd RT/A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:from:references:cc:to:subject :dkim-signature:arc-authentication-results; bh=HKqPeMji2jAvcuDk+UO1drK+B6FDBDR7i04lDkoiqew=; b=X3tQrPp/w3u+DiNK8066gnbcT8IiblTJWQ5XkbfVCvhLQjEROarxViJDWXKkvaq2aE KXqguF5mz1snprFmLQyHoq+BolhgXYHjXGMLD+RWqRUytTSp+U8ZO0fMB75E0u4yO1WP FMv6s4FuY2K5lF7QwU1IElJRJjEpNoQd35WRcqcLtw+nKQbLJByKHi1BemBlq+TDeYB0 LM4QTMkRlPXXXpQz7gkoE8e4hPBDZwb2L8YsRouAMC+iE6iHp4M3LFRddwl693xYEyDy /eFmOSof3oKAo65rlo8Wt18+G1pjEvJ00FKnTE3ydxt93nJH4RSZykFe8Oa54HuZGVzB YO4g== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@ti.com header.s=ti-com-17Q1 header.b=hCMSHl/T; spf=pass (google.com: domain of rogerq@ti.com designates 198.47.19.17 as permitted sender) smtp.mailfrom=rogerq@ti.com; dmarc=pass (p=QUARANTINE sp=NONE dis=NONE) header.from=ti.com Authentication-Results: mx.google.com; dkim=pass header.i=@ti.com header.s=ti-com-17Q1 header.b=hCMSHl/T; spf=pass (google.com: domain of rogerq@ti.com designates 198.47.19.17 as permitted sender) smtp.mailfrom=rogerq@ti.com; dmarc=pass (p=QUARANTINE sp=NONE dis=NONE) header.from=ti.com Subject: Re: [PATCH v5 1/6] dt-bindings: add bindings for USB physical connector To: Robin Murphy , Andrzej Hajda , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" CC: Mark Rutland , Felipe Balbi , Archit Taneja , , Laurent Pinchart , Bartlomiej Zolnierkiewicz , Greg Kroah-Hartman , , , , Inki Dae , Chanwoo Choi , Rob Herring , Krzysztof Kozlowski , , Marek Szyprowski References: <20180227071134.28063-1-a.hajda@samsung.com> <20180227071134.28063-2-a.hajda@samsung.com> <12da0d00-9ab3-3752-793b-e487666f35a3@ti.com> <1c3f8cde-4f9a-306f-b4f9-c0bdc76caf1f@arm.com> From: Roger Quadros Message-ID: Date: Thu, 15 Mar 2018 19:08:32 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <1c3f8cde-4f9a-306f-b4f9-c0bdc76caf1f@arm.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-GB Content-Transfer-Encoding: 8bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcSW1wb3J0YW50Ig==?= X-GMAIL-THRID: =?utf-8?q?1594728151455116260?= X-GMAIL-MSGID: =?utf-8?q?1595024316871487594?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On 15/03/18 13:46, Robin Murphy wrote: > On 12/03/18 10:41, Roger Quadros wrote: > [...] >>>>> @@ -0,0 +1,75 @@ >>>>> +USB Connector >>>>> +============= >>>>> + >>>>> +USB connector node represents physical USB connector. It should be >>>>> +a child of USB interface controller. >>>>> + >>>>> +Required properties: >>>>> +- compatible: describes type of the connector, must be one of: >>>>> +    "usb-a-connector", >>>>> +    "usb-b-connector", >>>>> +    "usb-c-connector". >>>> compatible should be just "usb-connector" >>>> >>>> Type should be a property >>>> >>>> type: type of usb connector "A", "B", "AB", "C" >>>> AB is for dual-role connectors. >>> >>> I have proposed such property (and size also) in my first RFC [1]. Rod >>> did not like it :) >>> >>> [1]: https://marc.info/?l=devicetree&m=150660411515233&w=2 >>> >> >> This is what Rob says here https://patchwork.kernel.org/patch/9976043/ >> "We did "type" for hdmi-connector, but I think I'd really prefer >> compatible be used to distinguish as least where it may matter to s/w. >> In the HDMI case, they all are pretty much the same, just different >> physical size." >> >> So the question is. Does it matter to this particular software implementation >> if it is type A,B,C connector? >> If yes, how? >> >> Type A will never have any alternate function. It is always dedicated to USB. > > In USB spec terms, at least. In reality there are things like the cool trick Rockchip SoCs do whereby they can expose the debug UART Rx/Tx through the OTG port's D+/D- pins, and that is on a type A connector in many products. I'm guessing that's probably beyond the scope of this binding, though. > >> Also does the size "full", "micro", "mini" matter to software? > > If it means the user can look in sysfs to easily correlate logical ports with physical connectors that's certainly handy (e.g. on something like Odroid-XU where the two USB3 ports are brought out to an A and a micro-AB connector respectively). But this logic fails if both connectors are the same type/size. This is where the label comes in handy. The labels can be unique and end user can identify the port using that. > > Robin. -- cheers, -roger Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki