From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752672Ab3BOQpu (ORCPT ); Fri, 15 Feb 2013 11:45:50 -0500 Received: from avon.wwwdotorg.org ([70.85.31.133]:40863 "EHLO avon.wwwdotorg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751440Ab3BOQpt (ORCPT ); Fri, 15 Feb 2013 11:45:49 -0500 Message-ID: <511E6639.1090909@wwwdotorg.org> Date: Fri, 15 Feb 2013 09:45:45 -0700 From: Stephen Warren User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 To: Peter De Schrijver CC: Hiroshi Doyu , Russell King , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Rob Herring , "linux-tegra@vger.kernel.org" , "devicetree-discuss@lists.ozlabs.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [v2 1/4] ARM: tegra20: create a DT header defining CLK IDs References: <1360868369-20093-1-git-send-email-hdoyu@nvidia.com> <1360868369-20093-2-git-send-email-hdoyu@nvidia.com> <511D45E0.1080105@wwwdotorg.org> <20130215092407.GO3073@tbergstrom-lnx.Nvidia.com> In-Reply-To: <20130215092407.GO3073@tbergstrom-lnx.Nvidia.com> X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/15/2013 02:24 AM, Peter De Schrijver wrote: > On Thu, Feb 14, 2013 at 09:15:28PM +0100, Stephen Warren wrote: >> On 02/14/2013 11:59 AM, Hiroshi Doyu wrote: >>> To replace magic number in tegra_car: >>> >>> - clocks = <&tegra_car 28>; >>> + clocks = <&tegra_car CLK_HOST1X>; >> >>> diff --git a/arch/arm/boot/dts/tegra20-car.h b/arch/arm/boot/dts/tegra20-car.h >> >> Sorry, forgot a couple small comments the last time around. >> >> This file should probably have some header indicating which binding it >> describes, rather like the GPIO header in my patch series. >> >>> +#define CLK_CPU 0 >> >> I'd suggest naming that TEGRA20_CLK_CPU, so that the various different >> clock headers don't conflict. It's not too likely that more than one of >> the /Tegra/ clock headers will be included at once, but it doesn't seem >> that unlikely that a board file could end up having a Tegra clock header >> included plus various other clock headers for some other chip that has >> some clock outputs. >> > > I would suggest removing this clock. It's not actually implemented in the CCF > and rather useless. If you would gate the CPU clock from the CPU by writing to > this register, how would you ungate it? :) Note that this would gate the clock > to all CPUs. (Note that my comment was re: all clocks, not just that one clock) Can't the PMC or flow-controller ungate the clock based on some event? Either way, that clock definition exists in HW, right? So I don't think there's actually any harm in including the definition in the binding even if we never implement/use it.