From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 972CCC001DE for ; Sat, 5 Aug 2023 19:08:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230274AbjHETIo (ORCPT ); Sat, 5 Aug 2023 15:08:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52970 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230267AbjHETIm (ORCPT ); Sat, 5 Aug 2023 15:08:42 -0400 Received: from mail-wm1-x331.google.com (mail-wm1-x331.google.com [IPv6:2a00:1450:4864:20::331]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 49209128 for ; Sat, 5 Aug 2023 12:08:39 -0700 (PDT) Received: by mail-wm1-x331.google.com with SMTP id 5b1f17b1804b1-3fe4a89e8c4so12629355e9.3 for ; Sat, 05 Aug 2023 12:08:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1691262518; x=1691867318; h=content-transfer-encoding:in-reply-to:from:references:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=ci5g0L3lDWd1ad2I5/zlL521QTxiIlvqfwBSNYlhmm4=; b=isPu0U9HvnEnti01C5gZ605dboA1zdGghYeSHbU+qURewel+VxA8vdz+KyFpIwV5R4 EDcdvy7us+eu6CxPGBEeM2K8Zll06tSQ2J4bn+fvsX3MtW3aDZUekGcfmZWTOamzGlLJ bhv6EyBF2NzKgC6QeLCydlZJLjYcWHU5LRQoRUCyBXcNEz6JjdPqUats00fr4EFxcG/Q lcO+dZEy1GA28aXrKudcK/Wz+Q8Aqd24+Ix6/crJoy0a+j8Fw6CuzxMYgl7FHi6yc2jd EvCvTIOI0Pq7bQVqZ1MYg0zdUvWahAJkcZD356ei92WJU0Y/9E8G5WQcfcac3BsODUIZ nv9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691262518; x=1691867318; h=content-transfer-encoding:in-reply-to:from:references:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=ci5g0L3lDWd1ad2I5/zlL521QTxiIlvqfwBSNYlhmm4=; b=bNYvOa/qlAM7JNUE6qh2x6P+wJiwuGQeDGRGyyivbU2pUuwm/MomnY6PxeqvAtd0Sa nPnI+OEwsl9aLB1AQ6H7GRd+MDMw27DcxcBxWWDADvHO/64BkPWp7DkI/c34hKnp+Tgd xQ0X0zyBu3zWkCuA5d8+J9kWSE3IScBIV2uyPmsvpA+W+6BLZsBkdcm3G9ZgtESye+Lf oP2lSDWz/2fDVnhbEPzh/VVaO5TGu/ozRkByMsmzFwn8zCg93nWl5tlekcCEa0Jflv8T krcE7TEEMLEmmVqxjhS4Bmf1DSScqpK8f9FnMU1Lh66Yd7Xh5t/JzR5lUS+RdbgGeBV+ SlUg== X-Gm-Message-State: AOJu0Yy8tfFjT3szfo4KrD96JeSfM8jOK9PIpOjo+yAhrzrYi0fE7hMu ztoz+3m7KYWhVbEidD68AqcBjg== X-Google-Smtp-Source: AGHT+IGxR6lIQII7VnRB6Dnh3BPr2qdoP2ijfkvBwAnBE1qeXZ9OkTLEgGNFZbvuH4nuQC2KiUZv0A== X-Received: by 2002:a05:600c:450:b0:3fc:62c:8275 with SMTP id s16-20020a05600c045000b003fc062c8275mr3405325wmb.35.1691262517660; Sat, 05 Aug 2023 12:08:37 -0700 (PDT) Received: from [192.168.1.20] ([178.197.222.245]) by smtp.gmail.com with ESMTPSA id e13-20020a05600c218d00b003fe2bea77ccsm5705999wme.5.2023.08.05.12.08.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 05 Aug 2023 12:08:37 -0700 (PDT) Message-ID: Date: Sat, 5 Aug 2023 21:08:35 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.14.0 Subject: Re: [PATCH v1 1/3] dt-bindings: usb: Add HPE GXP UDCG Controller Content-Language: en-US To: "Yu, Richard" , "Verdun, Jean-Marie" , "Hawkins, Nick" , "gregkh@linuxfoundation.org" , "robh+dt@kernel.org" , "krzysztof.kozlowski+dt@linaro.org" , "conor+dt@kernel.org" , "linux-usb@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" References: <20230706215910.78772-1-richard.yu@hpe.com> <20230706215910.78772-2-richard.yu@hpe.com> <9f1bd0f1-d93e-243a-4622-721319fd1235@linaro.org> From: Krzysztof Kozlowski In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/08/2023 20:07, Yu, Richard wrote: > >>> +title: HPE GXP USB Virtual EHCI controller > >> The word "virtual" in bindings pretty often raises questions, because we >> describe usually real hardware, not virtual. Some explanation in >> description would be useful. > > Here we are working with virtual devices that are created and have no Unfortunately I do not know what are virtual devices which do not exist physically. I have serious doubts that they fit Devicetree purpose... > physical presence. We have modeled our code off of ASPEED's VHUB > implementation to comply with the implementation in OpenBMC. > >>> + The HPE GXP USB Virtual EHCI Controller implements 1 set of USB EHCI >>> + register and several sets of device and endpoint registers to support >>> + the virtual EHCI's downstream USB devices. >>> + > > >> If this is EHCI controller, then I would expect here reference to usb-hcd. > > We will remove references to EHCI in code and documentation. It has been > modeled to following ASPEEDs approach as mentioned above. > >>> + hpe,vehci-downstream-ports: >>> + description: Number of downstream ports supported by the GXP > > >> Why do you need this property in DT and what exactly does it represent? >> You have one device - EHCI controller - and on some boards it is further >> customized? Even though it is the same device? > > That is correct. We can configure this VHUB Controller to have one to > 8 virtual ports. This is similar to the aspeed virtual USB HUB > "aspeed,vhub-downstream-ports" moving forward in the next patch > we are going to use "hpe,vhub-downstream-ports" Moving forward you need to address this lack of physical presence... Aren't these different devices and you just forgot to customize the compatible? Best regards, Krzysztof