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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95155C433FE for ; Tue, 19 Oct 2021 22:10:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 720D16134F for ; Tue, 19 Oct 2021 22:10:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229826AbhJSWMp (ORCPT ); Tue, 19 Oct 2021 18:12:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57482 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229611AbhJSWMn (ORCPT ); Tue, 19 Oct 2021 18:12:43 -0400 Received: from mail-pg1-x52b.google.com (mail-pg1-x52b.google.com [IPv6:2607:f8b0:4864:20::52b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9B079C061765 for ; Tue, 19 Oct 2021 15:10:30 -0700 (PDT) Received: by mail-pg1-x52b.google.com with SMTP id c4so13617864pgv.11 for ; Tue, 19 Oct 2021 15:10:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=gcH42ft4PL5Uc/1EXoL8Dp6lDCUUCAQKKLWYXAKG1cg=; b=gLWWTkEYbZJ9S5wn4tB9utjlf9XVjePkQgnPtpzqwjV5+Tgd9KNtnGEhYWs+gca1Lh rNxbvgYEXhl0I3xqP+Cmu1u86u6h2HL6+AWpTA1fXMnsiEkM3o5cQaKyjsu7nhg3rY91 gjfn5RrgwxY3j3wjOSMw4nbZQW+p1PmXD32HA= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=gcH42ft4PL5Uc/1EXoL8Dp6lDCUUCAQKKLWYXAKG1cg=; b=ZptAbB7fJr/3EyujEcWmuOL+yICc/FoXwVhqBTZPBi44tqaK0HMMCnlwIXYV8xsmOs 3IEP+4are2e8UNlDnhDfKCOE8HdAMAAMqejQdz0hJKh8ft3keN6s58ZBcDZBNVZmRJDT zfn9dvXUi6HPwHdjWn12QSDza1QSaypaiCS8TOJxA3rRPag7MWZnNxeq7lLE0Tw2mJhT rdf73BWPp6ercmDCYoR13Pvk1oO0w/aFd+1xuZegRmg5j1861CsDfUxZh6KPx7bq3SBy a8dHcvj+50PZY554GatgT2WdaoBVuVBVrbSV+VpfeulNzVJh6xEFetEVyEFMYEFwVYCS 6gkQ== X-Gm-Message-State: AOAM530GD00RZLNW946AT00nxHed65X7oePQdG2t7IA+JMc+2rILC0Hz ov2k8Ii07HapcFeLPLXiWhOXtQ== X-Google-Smtp-Source: ABdhPJz8FQqhb8sxAUF9c1/0TkQZqd983/XaDEdJ60GExi3IhnaND//4FpVJC7NyexgDMDDuQ7+QWQ== X-Received: by 2002:a63:7f0e:: with SMTP id a14mr24338961pgd.390.1634681430017; Tue, 19 Oct 2021 15:10:30 -0700 (PDT) Received: from localhost ([2620:15c:202:201:6c1f:a561:f56:7d16]) by smtp.gmail.com with UTF8SMTPSA id n207sm203903pfd.143.2021.10.19.15.10.26 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 19 Oct 2021 15:10:29 -0700 (PDT) Date: Tue, 19 Oct 2021 15:10:25 -0700 From: Matthias Kaehlcke To: Fabrice Gasnier Cc: Greg Kroah-Hartman , Doug Anderson , Rob Herring , Alan Stern , Frank Rowand , Mathias Nyman , Felipe Balbi , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Peter Chen , LKML , Linux USB List , Bastien Nocera , Ravi Chandra Sadineni , Michal Simek , Roger Quadros , Krzysztof Kozlowski , Stephen Boyd , Al Cooper , Al Viro , Alexandre Belloni , Alexandre TORGUE - foss , Andrew Lunn , Andrey Zhizhikin , Andy Gross , Arnd Bergmann , Aswath Govindraju , Bjorn Andersson , Catalin Marinas , Dmitry Baryshkov , Dmitry Osipenko , Dong Aisheng , Enric Balletbo i Serra , Fabio Estevam , Florian Fainelli , Gregory Clement , Grygorii Strashko , Guido =?utf-8?Q?G=C3=BCnther?= , Jagan Teki , Jens Axboe , Johan Hovold , Krzysztof Kozlowski , Lad Prabhakar , Lionel DEBIEVE , Manivannan Sadhasivam , Marek Szyprowski , Mark Brown , Martin =?utf-8?Q?J=C3=BCcker?= , Nishanth Menon , Olivier MOYSAN , Pawel Laszczak , Robert Richter , Russell King , Sebastian Hesselbarth , Shawn Guo , Thomas Gleixner , Tony Lindgren , Vinod Koul , Viresh Kumar , Will Deacon , William Cohen , Linux ARM , linux-arm-msm , linux-omap , linux-samsung-soc , =?utf-8?Q?=C5=81ukasz?= Stelmach Subject: Re: [PATCH v16 0/7] usb: misc: Add onboard_usb_hub driver Message-ID: References: <20210813195228.2003500-1-mka@chromium.org> <03f28680-35eb-25f4-5041-f3a56144da24@foss.st.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <03f28680-35eb-25f4-5041-f3a56144da24@foss.st.com> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Tue, Oct 19, 2021 at 06:04:06PM +0200, Fabrice Gasnier wrote: > On 10/15/21 8:39 AM, Greg Kroah-Hartman wrote: > > On Thu, Oct 14, 2021 at 02:38:55PM -0700, Doug Anderson wrote: > >> Hi, > >> > >> On Tue, Sep 21, 2021 at 10:09 AM Matthias Kaehlcke wrote: > >>> > >>> Hi Greg, > >>> > >>> are there any actions pending or can this land in usb-testing? > >>> > >>> I confirmed that this series can be rebased on top of v5.15-rc2 > >>> without conflicts. > >> > >> I'm quite interested to know what the next action items are, too. This > >> is one of the very few patches we have for trogdor (excluding MIPI > >> camera, which is a long story) that we're carrying downstream, so I'm > >> keenly interested in making sure it's unblocked (if, indeed, it's > >> blocked on anything). > >> > >> If folks feel that this needs more review eyes before landing again > >> then I'll try to find some time in the next week or two. If it's just > >> waiting for the merge window to open/close so it can have maximal bake > >> time, that's cool too. Please yell if there's something that I can do > >> to help, though! :-) > > > > I would love more review-eyes on this please. > > > > Hi, > > I noticed this series some time ago, and wanted to take a closer look. > > The same issue this series address is seen on stm32 board for instance. > (arch/arm/boot/dts/stm32mp15xx-dkx.dtsi). On board HUB (not described in > the DT) is supplied by an always-on regulator. > So it could could be interesting/useful to address the same case , > on stm32 boards, where USB2 (ehci-platform driver) is used currently. > > I noticed a few things, especially on the dt-bindings. I've some > questions here. > > In this series, RTS5411 is used. The dt-bindings documents it as a child > node of the USB controller. E.g. > > &usb { > usb_hub_2_0: hub@1 { > ... > }; > > usb_hub_3_0: hub@2 { > }; > } > > I had a quick look at RTS5411 datasheet. It looks like there's an i2c > interface too. > - I guess the I2C interface isn't used in your case ? > (I haven't checked what it could be used for...) Correct, the i2c interface isn't used on my board. Also the binding isn't completely new, it is based on the generic USB binding (https://www.kernel.org/doc/Documentation/devicetree/bindings/usb/usb-device.txt) > In the stm32 boards (stm32mp15xx-dkx), there's an usb2514b chip > - that also could be wired on I2C interface (0R mount option) > - unused on stm32 boards by default > > usb2514b chip already has a dt-bindings (with compatible), and a driver: > - drivers/usb/misc/usb251xb.c > - Documentation/devicetree/bindings/usb/usb251xb.txt > > It is defined more as an i2c chip, so I'd expect it as an i2c child, > e.g. like: > > &i2c { > usb2514b@2c { > compatible = "microchip,usb2514b"; > ... > }; > }; > > > This way, I don't see how it could be used together with onboard_usb_hub > driver ? (But I may have missed it) Indeed, you can either use the i2c driver for the hub or the onboard_usb_hub driver, but not both at the same time. The i2c driver requires the hub to be powered before communicating with it over i2c, hence the power sequence should not be delegated to the onboard_usb_hub driver. > Is it possible to use a phandle, instead of a child node ? The child node is part of the generic USB binding. The onboard_usb_hub driver needs it to find the USB device(s) that correspond to the hub, to optionally power the hub off during system suspend when no wakeup capable devices are connected. > However, in the stm32mp15xx-dkx case, i2c interface isn't wired/used by > default. So obviously the i2c driver isn't used. In this case, could the > "microchip,usb2514b" be listed in onboard_usb_hub driver ? > (wouldn't it be redundant ?) You would use the compatible string of the generic USB binding, i.e. "usbVID,PID", which would have to be added to the onboard_usb_hub driver. > In this case it would be a child node of the usb DT node... Maybe that's > more a question for Rob: would it be "legal" regarding existing > dt-bindings ? The USB node is always there implicitly (the USB device exists), the only difference is that the node is added explicitly (plus additional properties). There was a somewhat related long-winded discussion with Rob on an earlier version of the driver/binding: https://lore.kernel.org/linux-usb/1613055380.685661.519681.nullmailer@robh.at.kernel.org/