From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 15 Feb 2007 10:22:46 +1100 From: David Gibson To: Segher Boessenkool Subject: Re: [PATCH 15/16] Add device tree for Ebony Message-ID: <20070214232246.GE16279@localhost.localdomain> References: <20070213060904.GA6214@localhost.localdomain> <20070213061026.5837FDDDE9@ozlabs.org> <9696D7A991D0824DBA8DFAC74A9C5FA302A1B705@az33exm25.fsl.freescale.net> <1171470754.4003.101.camel@zod.rchland.ibm.com> <6206de08b7f12175bebe669291c66334@kernel.crashing.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <6206de08b7f12175bebe669291c66334@kernel.crashing.org> Cc: linuxppc-dev@ozlabs.org, Yoder Stuart-B08248 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, Feb 14, 2007 at 06:58:04PM +0100, Segher Boessenkool wrote: > >> Did you mean to have UIC1 nested under UIC0 or should > >> they be at the same level? > > > > No, they are cascaded in hardware. I think having UIC1 under UCI0 is a > > correct representation. > > Only the interrupt routing is cascaded AFAICS, and > there is a separate interrupt tree to express that. In the case of the UICs, I don't see that there's anything "only" about the interrupt routing. They're DCR controlled, and are not on the normal bus. > >> Hmm. There are two "soc" devices here, one nested under the > >> first?? > >> > >> I'm assuming these are two levels of busses the opb bus is attached > >> to the plb bus. Is the "soc" device_type the right way to > >> do this? > > > > Right, OPB hangs off of PLB in this case. I dunno if "soc" is the > > right > > device type for them though. > > I would use device_type "plb" (or "plb4") and "opb" I think. > Similar to how PCI and ISA etc. busses are represented. Yeah, I've been pretty usnsure about this myself. Using "soc" was initially a hack to make the legacy serial detection stuff work, but I think Arnd's of_platform serial stuff will deal with that better. On the other hand, using separate device_type has no particular value, either. I wonder if we should have a general device_type for any non-probeable, memory-mapped bus. -- 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