From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 3 Sep 2007 20:12:34 +1000 From: David Gibson To: Segher Boessenkool Subject: Re: [RFC] AmigaOne device tree source v2 Message-ID: <20070903101234.GA12212@localhost.localdomain> References: <20070831175006.17240@gmx.net> <20070903013431.GG31499@localhost.localdomain> <1188808900.5972.133.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Sep 03, 2007 at 12:02:58PM +0200, Segher Boessenkool wrote: > >>> host@0 { > >> > >> The unit address (after the @) should be derived from the first range > >> listed in the 'reg' property. It's a bus address, not a slot number. > > > > Actually... on PCI, the unit address is often the slot number, or > > rather, "slot,function" with the second part ommited for non > > multifunction devices. > > Not slot number, but "device-id". Like, if you have actual > PCI plugin slots on your board, they likely have device ids > 16,17,...; but slot numbers 1, 2, 3 (little labels on the box). > > David's point is that unit addresses are not random numbers. You flatter me. But i'll happily make that point, now that my ignorance is slightly alleviated ;-). > >> All these devices should have unit addresses. > > > > ... which for ISA are generally in the form iPORT (8242@i60 for > > example) though I've seen the "i" ommited. Not terribly important I > > would say but better to follow the spec. > > Omitting the "i" is perfectly in line with the spec :-) > > >>> ide@7,1 { > >> > >> This will need a compatible property, at least. > > > > Actually, it's a PCI device, it can have a compatible property based on > > the generic PCI device compatible property generation as defined in the > > OF PCI binding. Since that's just derived from other fields, I suppose > > it can be omitted in a flat DT. It would be -nice- to have a more > > explicit cpmpatible property but in that case, not absolutely necessary > > since that device will be probed as PCI anyway. > > Yeah, PCI is a special case for Linux. Maybe add a "pciclass,XXXX" > compatible property though, for good measure. Anything else isn't > all that useful I think. Indeed, since PCI is probable, it's unclear whether these device nodes are even necessary at all. Depends on whether there's anything interesting in the omitted interrupt routing information. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson