From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932486AbaCQRs0 (ORCPT ); Mon, 17 Mar 2014 13:48:26 -0400 Received: from smtp.codeaurora.org ([198.145.11.231]:37139 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756287AbaCQRsY (ORCPT ); Mon, 17 Mar 2014 13:48:24 -0400 Message-ID: <53273566.20208@codeaurora.org> Date: Mon, 17 Mar 2014 13:48:22 -0400 From: Christopher Covington User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 To: Kumar Gala CC: Stephen Boyd , David Brown , "linux-kernel@vger.kernel.org" , "linux-arm-msm@vger.kernel.org" , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] ARM: dts: msm8974: Move arch-timer out of soc node References: <1394573058-18561-1-git-send-email-sboyd@codeaurora.org> <5327316B.6040007@codeaurora.org> <26E59402-2F50-4E42-AAF2-AF321CB51799@codeaurora.org> In-Reply-To: <26E59402-2F50-4E42-AAF2-AF321CB51799@codeaurora.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Kumar, On 03/17/2014 01:33 PM, Kumar Gala wrote: > > On Mar 17, 2014, at 12:31 PM, Christopher Covington wrote: > >> Hi Stephen, >> >> On 03/11/2014 05:24 PM, Stephen Boyd wrote: >>> The architected timer is not a register addressable piece of >>> hardware. Instead it's accessed through cp15 accessors. Move it >>> to the root of the devicetree to reflect this. >> >> I find this confusing, perhaps due to overloading of the word "register". >> Aren't CP15's a class of coprocessor _registers_? Could it perhaps be clearer >> to talk about memory-mapped versus CP15-mapped timers? >> >> Is "soc" documented somewhere or is it just a name for a container? Assuming >> the latter, it's not obvious to me why being a child of a system on chip node >> would imply having memory mapped registers. > > “soc” is a container, since its compatible = "simple-bus”, this implies > memory mapped register access for nodes inside of it. That makes sense. Thanks for explaining it. Christopher -- Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by the Linux Foundation.