From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from baldur.buserror.net ([165.227.176.147]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1eKtJe-00075r-KB for linux-mtd@lists.infradead.org; Fri, 01 Dec 2017 21:57:56 +0000 Message-ID: <1512165311.10062.3.camel@buserror.net> From: Scott Wood To: Prabhakar Kushwaha , "linux-mtd@lists.infradead.org" , "devicetree-discuss@lists.ozlabs.org" Cc: "dedekind1@gmail.com" , "computersforpeace@gmail.com" Date: Fri, 01 Dec 2017 15:55:11 -0600 In-Reply-To: References: <1511954855-8593-1-git-send-email-prabhakar.kushwaha@nxp.com> <1512105209.10062.1.camel@buserror.net> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: Re: [PATCH] Documentation: binding: Update endianness usage List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2017-12-01 at 08:42 +0000, Prabhakar Kushwaha wrote: > > -----Original Message----- > > From: Scott Wood [mailto:oss@buserror.net] > > Sent: Friday, December 01, 2017 10:43 AM > > To: Prabhakar Kushwaha ; linux- > > mtd@lists.infradead.org; devicetree-discuss@lists.ozlabs.org > > Cc: dedekind1@gmail.com; computersforpeace@gmail.com > > Subject: Re: [PATCH] Documentation: binding: Update endianness usage > > > > On Wed, 2017-11-29 at 16:57 +0530, Prabhakar Kushwaha wrote: > > > IFC controller version < 2.0 support IFC register access as > > > big endian. These controller version also require IFC NOR signals to > > > be connected in reverse order with NOR flash. > > > > > > IFC >= 2.0 is other way around. > > > > > > So updating IFC binding to take care of both using endianness field. > > > > > > Signed-off-by: Prabhakar Kushwaha > > > --- > > >  Documentation/devicetree/bindings/memory-controllers/fsl/ifc.txt | 6 > > > ++++-- > > >  1 file changed, 4 insertions(+), 2 deletions(-) > > > > > > diff --git a/Documentation/devicetree/bindings/memory- > > > controllers/fsl/ifc.txt b/Documentation/devicetree/bindings/memory- > > > controllers/fsl/ifc.txt > > > index 89427b0..824a2ca 100644 > > > --- a/Documentation/devicetree/bindings/memory-controllers/fsl/ifc.txt > > > +++ b/Documentation/devicetree/bindings/memory-controllers/fsl/ifc.txt > > > @@ -18,8 +18,10 @@ Properties: > > >                interrupt (NAND_EVTER_STAT).  If there is only one, > > >                that interrupt reports both types of event. > > > > > > -- little-endian : If this property is absent, the big-endian mode will > > > -                  be in use as default for registers. > > > +- little-endian or big-endin : It represents how IFC registers  to be > > > accessed. > > > + It also represents connection between > > > controller > > > and > > > + NOR flash. If this property is absent, the big- > > > endian > > > + mode will be in use as default. > > > > "endin"? > > > > If big endian is the default, is this change really > > necessary?  Particularly > > since the big endian chips are older and thus have existing device trees. > > > > Earlier endianness information was only used for "how to"  access IFC-NAND > register access. > Now this info  will also be used for defining swap requirement of NOR > flash.  Is this a difference between LS1021A and PPC-based chips? > "If this property is absent,  the big-  endian mode will be in use as > default ". This line can be removed.  > Please let me know your view on this.  No, it cannot be removed because there are existing device trees with IFC nodes that don't have either property. -Scott