From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arun Ramamurthy Subject: Re: [PATCH 1/2] phy: usbphy: Add dt documentation for Broadcom Cygnus USB PHY driver Date: Wed, 18 Feb 2015 16:46:48 -0800 Message-ID: <54E53278.70705@broadcom.com> References: <1424200821-16368-1-git-send-email-arun.ramamurthy@broadcom.com> <2797126.uqvyZJisPk@wuerfel> <54E3AD2E.8050902@broadcom.com> <11865413.8NsXkQ6AUR@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <11865413.8NsXkQ6AUR@wuerfel> Sender: linux-kernel-owner@vger.kernel.org To: Arnd Bergmann , linux-arm-kernel@lists.infradead.org Cc: Mark Rutland , devicetree@vger.kernel.org, Scott Branden , Pawel Moll , Ian Campbell , Ray Jui , linux-kernel@vger.kernel.org, Kishon Vijay Abraham I , Jonathan Richardson , Rob Herring , bcm-kernel-feedback-list@broadcom.com, Dmitry Torokhov , Kumar Gala , Anatol Pomazau , stern@rowland.harvard.edu List-Id: devicetree@vger.kernel.org On 15-02-18 07:15 AM, Arnd Bergmann wrote: > On Tuesday 17 February 2015 13:05:50 Arun Ramamurthy wrote: >> On 15-02-17 12:53 PM, Arnd Bergmann wrote: >>> On Tuesday 17 February 2015 12:00:49 Arun Ramamurthy wrote: >>>> Arnd, I patched the ehci and ohci driver to accept multiple phys so they >>>> require different names and cannot both be "usb". That patch was >>>> accepted by Alen Stern but I did not update the bindings documentation. >>>> I will send out another patch for that. Could we go with the naming >>>> scheme of "usb" + "p" + port number or do you have other suggestions? >>> >>> I don't have a good idea, but I think it would be best if the first >>> phy could remain named "usb" for compatibility with the existing binding. >>> >> The patch was written in a way that all the existing and new drivers can >> continue to use "usb" if they are using only one phy so that we remain >> compatible. The names need to be different only if more than one phy is >> specified. In such cases i don't think the first phy should be "usb" as >> it would be confusing to have >> phy-names = "usb","usbp1" > > I see your patch now, as 7e7a0e67f2c ("usb: ehci-platform: add support for > multiple phys per controller"), and I'm not too happy about the way you > did this. > We already concluded that there should have been a binding change > to go along with this, and that would have caught the fact that you > circumvent the API here by reading the phy names manually. That > part should never have made it into the kernel. > > I think we can do this either by defining specific names for the > phy, or by changing the generic PHY binding to allow anonymous > phy references (leaving out "phy-names" entirely), and adding a > proper API for that. > Thanks Arnd, I will wait for Alan's comments before proceeding. I am happy to patch the ehci-platform driver to use a new api instead of devm_phy_get if that is the best option. >> Should I run this by Alan Stern? > > I've added him to Cc here. He clearly didn't know the background about > the DT binding change, and should not need to, but he may have an opinion > on what names we should use. > >>> What is the reason for having two phys in your case? Are these >>> identical phy devices connected to a single controller or do they >>> server different purposes? >>> >> Yes, we have three identical phys connected to a single host controller >> and one of the phys is also connected to the device controller > > Ok, no problem with that, let's just make sure we come up with a > good binding for it. > > Arnd >