From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from an-out-0708.google.com (an-out-0708.google.com [209.85.132.242]) by ozlabs.org (Postfix) with ESMTP id 84D53DDE9E for ; Sun, 23 Mar 2008 01:50:49 +1100 (EST) Received: by an-out-0708.google.com with SMTP id c37so432261anc.78 for ; Sat, 22 Mar 2008 07:50:48 -0700 (PDT) Message-ID: Date: Sat, 22 Mar 2008 08:50:48 -0600 From: "Grant Likely" Sender: glikely@secretlab.ca To: "Paul Mackerras" Subject: Re: [PATCH 2/3] [POWERPC] Xilinx: of_serial support for Xilinx uart 16550. In-Reply-To: <18403.32257.725539.470771@cargo.ozlabs.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 References: <12060242324116-git-send-email-john.linn@xilinx.com> <20080320144402.3063517C005D@mail148-sin.bigfish.com> <18403.32257.725539.470771@cargo.ozlabs.ibm.com> Cc: linuxppc-dev@ozlabs.org, John Linn List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, Mar 21, 2008 at 3:21 AM, Paul Mackerras wrote: > Grant Likely writes: > > > Personally, I'm not fond of this approach. There is already some > > traction to using the reg-shift property to specify spacing, and I > > think it would be appropriate to also define a reg-offset property to > > handle the +3 offset and then let the xilinx 16550 nodes use those. > > Why do we need a reg-offset property when we can just add the offset > to the appropriate word(s) in the reg property? Primarily because the device creates 32 byte registers starting at 0; but they are also big-endian byte accessible so a byte read at offset 8 also works. reg-offset seems to be a better description of the hardware to me. Cheers, g. -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd.