From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH v3] Axi-usb: Add support for 64-bit addressing. Date: Wed, 25 May 2016 20:29:40 +0200 Message-ID: <5392766.vCAWrASuOA@wuerfel> References: <1464067268-35299-1-git-send-email-navam@xilinx.com> <20160525173419.GA7510@rob-hp-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <20160525173419.GA7510@rob-hp-laptop> Sender: linux-kernel-owner@vger.kernel.org To: Rob Herring Cc: Nava kishore Manne , "pawel.moll@arm.com" , "mark.rutland@arm.com" , "ijc+devicetree@hellion.org.uk" , "galak@codeaurora.org" , Michal Simek , Soren Brinkmann , "balbi@ti.com" , "gregkh@linuxfoundation.org" , Hyun Kwon , Radhey Shyam Pandey , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" List-Id: devicetree@vger.kernel.org On Wednesday, May 25, 2016 12:34:19 PM CEST Rob Herring wrote: > On Tue, May 24, 2016 at 11:47:31AM +0000, Nava kishore Manne wrote: > > > > > > > -----Original Message----- > > > From: Arnd Bergmann [mailto:arnd@arndb.de] > > > Sent: Tuesday, May 24, 2016 2:21 PM > > > To: Nava kishore Manne > > > Cc: robh+dt@kernel.org; pawel.moll@arm.com; mark.rutland@arm.com; > > > ijc+devicetree@hellion.org.uk; galak@codeaurora.org; Michal Simek > > > ; Soren Brinkmann ; > > > balbi@ti.com; gregkh@linuxfoundation.org; Hyun Kwon > > > ; Nava kishore Manne ; Radhey > > > Shyam Pandey ; devicetree@vger.kernel.org; linux- > > > arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org > > > Subject: Re: [PATCH v3] Axi-usb: Add support for 64-bit addressing. > > > > > > On Tuesday, May 24, 2016 10:51:08 AM CEST Nava kishore Manne wrote: > > > > diff --git a/Documentation/devicetree/bindings/usb/udc-xilinx.txt > > > > b/Documentation/devicetree/bindings/usb/udc-xilinx.txt > > > > index 47b4e39..09df757 100644 > > > > --- a/Documentation/devicetree/bindings/usb/udc-xilinx.txt > > > > +++ b/Documentation/devicetree/bindings/usb/udc-xilinx.txt > > > > @@ -1,18 +1,23 @@ > > > > Xilinx USB2 device controller > > > > > > > > Required properties: > > > > -- compatible : Should be "xlnx,usb2-device-4.00.a" > > > > +- compatible : Should be "xlnx,usb2-device-4.00.a" or > > > > + "xlnx,usb2-device-5.00" > > > > - reg : Physical base address and size of the USB2 > > > > device registers map. > > > > - interrupts : Should contain single irq line of USB2 device > > > > controller > > > > - xlnx,has-builtin-dma : if DMA is included > > > > +- dma-ranges : Should be as the following > > > > + > > > > > > A USB host should not have any children that are DMA capable, I think, so > > > this property doesn't make sense here. It should be part of the parent bus. > > > > > Will send next version (v4) by removing this property from the DT. > > > > > > +- xlnx,addrwidth : Should be the dma addressing size in bits(ex: 64 > > > bits) > > > > > > I'm still unconvinced about the property definition here. What are the > > > possible options for the IP block? I don't think I ever saw a reply from you to > > > my earlier questions. > > > > > > > Sorry Let me clearly explain > > > > From the IP version 5.0 onwards The IP support both 32-bit and 64-bit addressing. > > But the older version of the IP's supports only 32-bit addressing. > > > > This addrwidth property differentiates the address width for the new IP (I mean 5.0 version on wards) > > For older IP it will be always 32-bit. > > Then I think you should have a simple boolean property for 64-bit > configuration. I think matching on the version number is slightly better, as we have the version already and it identifies whether the register exists. Having a boolean property of course works as well, it just duplicates that information. Arnd