From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753810AbcHWUFk (ORCPT ); Tue, 23 Aug 2016 16:05:40 -0400 Received: from mail-ua0-f173.google.com ([209.85.217.173]:35648 "EHLO mail-ua0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752228AbcHWUFj (ORCPT ); Tue, 23 Aug 2016 16:05:39 -0400 MIME-Version: 1.0 In-Reply-To: <147043320014.26915.7483025835695600714@sboyd-linaro> References: <20160707222114.1673-1-stephen.boyd@linaro.org> <20160707222114.1673-4-stephen.boyd@linaro.org> <20160718022355.GA8568@rob-hp-laptop> <147043320014.26915.7483025835695600714@sboyd-linaro> From: Stephen Boyd Date: Tue, 23 Aug 2016 13:00:00 -0700 Message-ID: Subject: Re: [PATCH v2 03/22] usb: ulpi: Support device discovery via device properties To: Rob Herring Cc: linux-usb@vger.kernel.org, linux-arm-kernel , Linux Kernel Mailing List , linux-arm-msm@vger.kernel.org, Andy Gross , Bjorn Andersson , Neil Armstrong , Arnd Bergmann , Felipe Balbi , Greg Kroah-Hartman , Heikki Krogerus , devicetree@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 5, 2016 at 2:40 PM, Stephen Boyd wrote: > Quoting Rob Herring (2016-07-17 19:23:55) >> On Thu, Jul 07, 2016 at 03:20:54PM -0700, Stephen Boyd wrote: >> > +------- >> > + >> > +usb { >> > + compatible = "vendor,usb-controller"; >> > + >> > + ulpi { >> > + phy { >> > + compatible = "vendor,phy"; >> > + ulpi-vendor = /bits/ 16 <0x1d6b>; >> > + ulpi-product = /bits/ 16 <0x0002>; >> > + }; >> > + }; >> >> I'm still having concerns about describing both phys and devices. If I >> have a controller with 2 ports and 2 devices attached, I'd have >> something like this under the USB controller: >> >> ulpi { >> phy@1 { >> }; >> phy@2 { >> }; >> }; > > My understanding is there would only be one status="ok" node on the ULPI > bus for the single phy that a usb controller would have. At the least, > the kernel's ULPI layer only seems to support one ULPI phy for a > controller right now. So even if there are two ports, it doesn't mean > there are two phys. > >> >> dev@1 { >> ... >> }; >> >> dev@2 { >> ... >> }; >> >> >> That doesn't seem the best, but I don't have a better suggestion. Maybe >> the device nodes need to go under the phy nodes? >> > > What if we moved the dev@1 and dev@2 to another sub node like "ports" or > "usb-devices"? Legacy code can support having those devices directly > underneath the usb controller, but future users would always need to put > them in a different sub-node so that we can easily differentiate the > different busses that a usb controller node may support? > > I'm not sure I see any need to relate the phy to the ports that are on > the controller, but if that is needed then perhaps you're right and we > should move the ports underneath the phy. USB core could be modified to > go through the legacy path or through the phy, if it even exists, to > find ports. > > Do we typically do this for other phy designs like sata or pci? The phy > always seemed like a parallel thing to the logical bus that the phy is > used for. Rob does this sound ok to you?