From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932155AbcGBAUf (ORCPT ); Fri, 1 Jul 2016 20:20:35 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:59610 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932106AbcGBAUc (ORCPT ); Fri, 1 Jul 2016 20:20:32 -0400 Date: Fri, 1 Jul 2016 17:20:30 -0700 From: Stephen Boyd To: Jongsung Kim Cc: Michael Turquette , Rob Herring , Maxime Ripard , linux-clk@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Chanho Min Subject: Re: [PATCH v2] clk: fixed-factor: add optional dt-binding clock-flags Message-ID: <20160702002030.GF27880@codeaurora.org> References: <20160621005910.GN1521@codeaurora.org> <1466741572-58802-1-git-send-email-neidhard.kim@lge.com> <20160628205518.GF3737@rob-hp-laptop> <146714872010.89261.1969853552594659808@resonance> <5773736D.3060405@lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <5773736D.3060405@lge.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/29, Jongsung Kim wrote: > On 2016년 06월 29일 06:18, Michael Turquette wrote: > > Quoting Rob Herring (2016-06-28 13:55:18) > >> On Fri, Jun 24, 2016 at 01:12:52PM +0900, Jongsung Kim wrote: > >>> There is no way to set additional flags for a DT-initialized fixed- > >>> factor-clock, and it can be problematic i.e., when the clock rate > >>> needs to be changed. [1][2] > >>> > >>> This patch introduces an optional dt-binding named "clock-flags" to > >>> be used for passing any needed flags from dts. > >> I don't think we want this in DT. If we did, the flags would need some > >> documentation about what the flags mean. > > Flags are specific to Linux implementation, so I agree with Rob. Better > > to create a compatible string for your hardware that bakes in the flags. > > Thank you for your comment, Mike. This conversation starts from lacking method to set CLK_SET_RATE_PARENT from DT. I understand compatible string can be a solution. But.. if someone starts talking about lacking method to set another flag, i.e., CLK_SET_PARENT_GATE, then we'll need another compatible string list. > How do you think about defining possible required subset of the flags and using some more neutral flag-names acceptable in DT? Do you actually have an IC on the board that is doing some fixed factor calculation? Or is this a clk driver design where we are listing out each piece of an SoC's clk controller in DT? -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project