From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pw0-f42.google.com (mail-pw0-f42.google.com [209.85.160.42]) by ozlabs.org (Postfix) with ESMTP id 83344B802F for ; Sat, 13 Mar 2010 10:04:49 +1100 (EST) Received: by pwi10 with SMTP id 10so1080904pwi.15 for ; Fri, 12 Mar 2010 15:04:47 -0800 (PST) MIME-Version: 1.0 Sender: glikely@secretlab.ca In-Reply-To: <20100312223647.GM11655@yookeroo> References: <4B934CCA.8030608@freemail.hu> <4B95458A.4000304@freemail.hu> <4B95F298.5040000@freemail.hu> <4B9889AC.4080309@freemail.hu> <20100311062331.GI11655@yookeroo> <4B99DE95.8010304@freemail.hu> <20100312223647.GM11655@yookeroo> From: Grant Likely Date: Fri, 12 Mar 2010 16:04:27 -0700 Message-ID: Subject: Re: Freescale MPC5554 device tree (was: cross-compiling Linux for PowerPC e200 core?) To: Grant Likely , =?ISO-8859-1?Q?N=E9meth_M=E1rton?= , linuxppc-dev@ozlabs.org Content-Type: text/plain; charset=ISO-8859-1 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, Mar 12, 2010 at 3:36 PM, David Gibson wrote: > On Fri, Mar 12, 2010 at 05:14:56AM -0700, Grant Likely wrote: >> 2010/3/11 N=E9meth M=E1rton : > [snip] >> > + >> > + =A0 =A0 =A0 cpus { >> > + =A0 =A0 =A0 =A0 =A0 =A0 =A0 #address-cells =3D <1>; >> > + =A0 =A0 =A0 =A0 =A0 =A0 =A0 #size-cells =3D <0>; >> > + >> > + =A0 =A0 =A0 =A0 =A0 =A0 =A0 cpu@0 { >> > + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 device_type =3D "cpu"; >> > + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 compatible =3D "PowerPC,= 5554"; >> >> I'd rather see the same convention used here as for all the other >> compatible values in this file. =A0ie: >> >> compatible =3D "fsl,mpc5554-e200z6", "fsl,powerpc-e200z6"; >> >> Dave, what do you think? > > Well, you could add those too, but "PowerPC,5554" should probably > remain. > > The historical background here is that in the original OF spec, driver > matching was done on node name, and only then on compatible. > Essentially the node name was treated as an implicit first entry in > the compatible list. =A0The the generic names convention came along, and > instead name became a human readable generic type for the device > ("ethernet", "i2c", etc..). > > That convention has been widely used since long before flat trees > existed, but for some reason it was never really used for cpu nodes; > they remained as "PowerPC,XXXX" or whatever. =A0Because the varying > names of cpu nodes was sometimes awkward to deal with in bootloaders, > we decided it would be sensible to apply the generic names convention > here too, so "cpu@X". =A0But then, the previous node name, which was > treated as being prepended to compatible, should now explicitly be put > into compatible. In this particular case, we're talking about a part that has never previously been described in a device tree. So, since this is something entirely new, what is the value in preserving the PowerPC,XXXX style when there isn't any code that will be relying on it? g. --=20 Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd.