From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: [PATCH 03/11] x86/dtb: Add a device tree for CE4100 Date: Tue, 30 Nov 2010 13:50:11 +1100 Message-ID: <1291085411.32570.320.camel@pasglop> References: <1290706801-7323-1-git-send-email-bigeasy@linutronix.de> <1290706801-7323-4-git-send-email-bigeasy@linutronix.de> <1290808645.32570.158.camel@pasglop> <20101128160449.GC30784@www.tglx.de> <1290984809.32570.208.camel@pasglop> <20101129130720.7d060e1c@udp111988uds.am.freescale.net> <1291061128.32570.298.camel@pasglop> <4CF40DF4.9060204@firmworks.com> <1291063470.32570.312.camel@pasglop> <20101129234735.4ce3a933@lxorguk.ukuu.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20101129234735.4ce3a933-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org To: Alan Cox Cc: sodaville-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, Sebastian Andrzej Siewior , x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Scott Wood , devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org List-Id: devicetree@vger.kernel.org On Mon, 2010-11-29 at 23:47 +0000, Alan Cox wrote: > > That may not be wise. Your real bus heirarchy may not be architecturally > defined on some systems so you can't incorporate it into code, nor is it > necessarily a heirarchy - eg some of the Geodes. Ok, so I'd suggest doing something like: - pci is below the corresponding atom node - isa is a child of pci The later is a useful representation even if it doesn't correspond to reality. From an address representation perspective, ISA can be considered somewhat as a substractive decoding child of PCI (again even if that's not 100% true), which simplifies the representation in the device-tree a bit, and allows to still have things like VGA devices on the PCI segment that decode IO ports in the ISA range. Cheers, Ben.