Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752904AbdCOUX3 (ORCPT ); Wed, 15 Mar 2017 16:23:29 -0400 Received: from mail-pf0-f193.google.com ([209.85.192.193]:35205 "EHLO mail-pf0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751198AbdCOUX1 (ORCPT ); Wed, 15 Mar 2017 16:23:27 -0400 Date: Wed, 15 Mar 2017 15:23:24 -0500 From: Rob Herring To: Marek Vasut Cc: Artur Jedrysek , "devicetree@vger.kernel.org" , "linux-mtd@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Cyrille Pitchen , David Woodhouse , Brian Norris , Boris Brezillon , Richard Weinberger , Mark Rutland Subject: Re: [v2, 4/4] dt-bindings: mtd: Add Octal SPI support to Cadence QSPI. Message-ID: <20170315202324.44k43sjn5qnobins@rob-hp-laptop> References: <1488959932-6657-1-git-send-email-jartur@cadence.com> <1488960326-13858-1-git-send-email-jartur@cadence.com> <132a4818-11d1-263f-aae4-bac4e76c14c8@gmail.com> <7d303436-77cf-fb11-30b6-c59014950ae6@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7d303436-77cf-fb11-30b6-c59014950ae6@gmail.com> User-Agent: Mutt/1.6.2-neo (2016-08-21) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2703 Lines: 66 On Fri, Mar 10, 2017 at 01:52:31PM +0100, Marek Vasut wrote: > On 03/10/2017 01:03 PM, Artur Jedrysek wrote: > > > >> From: Marek Vasut [mailto:marek.vasut@gmail.com] > >> Sent: 10 March 2017 04:39 > >> On 03/08/2017 09:05 AM, Artur Jedrysek wrote: > >>> This patch updates Cadence QSPI Device Tree documentation to include > >>> information about new compatible used to indicate, whether or not > >>> Octal SPI transfers are supported by the device. > >>> > >>> Signed-off-by: Artur Jedrysek > >>> --- > >>> Changelog: > >>> v2: Use new compatible, instead of boolean property, to indicate > >>> Octal SPI support. > >>> --- > >>> Documentation/devicetree/bindings/mtd/cadence-quadspi.txt | 4 +++- > >>> 1 file changed, 3 insertions(+), 1 deletion(-) > >>> > >>> diff --git a/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt > >> b/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt > >>> index f248056..41d1e98 100644 > >>> --- a/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt > >>> +++ b/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt > >>> @@ -1,7 +1,9 @@ > >>> * Cadence Quad SPI controller > >>> > >>> Required properties: > >>> -- compatible : Should be "cdns,qspi-nor". > >>> +- compatible : Should be "cdns,{qspi|ospi}-nor". > >> > >> Please explicitly list all compatibles , ie. > >> Should be "cdns,qspi-nor" or "cdns,ospi-nor". > >> > > > > Two possible options are also explicitly listed right below. I did that > > in the way it was done in other driver for Cadence IP: > > /Documentation/devicetree/bindings/net/macb.txt > > Should I remove all of that and replace it with both options, separated > > by an "or" word? > > Wait for Rob to confirm. As Marek suggested, but with one valid combination per line. I don't think checkpatch.pl will work with it as is. > > >> But I think the ospi is backward compatible with qspi, right ? So the > >> binding for ospi should list both, ie. > >> compatible = "cdns,ospi-nor", "cdns,qspi-nor"; > >> > > > > Yes, the ospi is backwards compatible with qspi. However, the sole point > > of introducing new compatible was to differentiate between them (which > > was previously done using a boolean flag, but that was criticized). > > Listing both bindings for ospi would only help for kernels not > > containing driver update being subject of this patch series, as both > > ospi and qspi are handled by the same driver - just with a slight > > difference. I apologize if I got something wrong here. > > You got it right, I was just curious about the compatibility. You are assuming every OS/user everywhere is updated. It doesn't hurt to have the backwards compatibility. Rob