From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932613AbaIDAxU (ORCPT ); Wed, 3 Sep 2014 20:53:20 -0400 Received: from mail-pa0-f51.google.com ([209.85.220.51]:34918 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755150AbaIDAxT convert rfc822-to-8bit (ORCPT ); Wed, 3 Sep 2014 20:53:19 -0400 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT To: Stephen Boyd , "Tomeu Vizoso" From: Mike Turquette In-Reply-To: <5407A6B9.1080606@codeaurora.org> Cc: "Stephen Warren" , "Peter De Schrijver" , linux-kernel@vger.kernel.org, tomasz.figa@gmail.com, rabin@rab.in, "Thierry Reding" , "Javier Martinez Canillas" , linux-arm-kernel@lists.infradead.org References: <1409758148-20104-1-git-send-email-tomeu.vizoso@collabora.com> <1409758434-20810-1-git-send-email-tomeu.vizoso@collabora.com> <1409758434-20810-3-git-send-email-tomeu.vizoso@collabora.com> <5407A6B9.1080606@codeaurora.org> Message-ID: <20140904005305.11368.16931@quantum> User-Agent: alot/0.3.5 Subject: Re: [PATCH v9 5/6] clk: Add floor and ceiling constraints to clock rates Date: Wed, 03 Sep 2014 17:53:05 -0700 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Quoting Stephen Boyd (2014-09-03 16:39:37) > On 09/03/14 08:33, Tomeu Vizoso wrote: > > +int clk_set_ceiling_rate(struct clk *clk_user, unsigned long rate) > > +{ > > + struct clk_core *clk = clk_to_clk_core(clk_user); > > + > > + WARN(rate > 0 && rate < clk_user->floor_constraint, > > + "clk %s dev %s con %s: new ceiling %lu lower than existing floor %lu\n", > > + __clk_get_name(clk), clk_user->dev_id, clk_user->con_id, rate, > > + clk_user->floor_constraint); > > + > > + clk_user->ceiling_constraint = rate; > > + return clk_provider_set_rate(clk, clk_provider_get_rate(clk)); > > +} > > +EXPORT_SYMBOL_GPL(clk_set_ceiling_rate); > > Maybe I'm late to this patch series given that Mike applied it, but I > wonder why we wouldn't just have one API that takes a min and a max, > i.e. clk_set_rate_range(clk, min, max)? Then clk_set_rate() is a small > wrapper on top that just sets min and max to the same value. We certainly can have that. But being able to easily adjust a floor or ceiling value seems like a good thing to me, and that is what these functions do. If we decide to have a clk_set_rate_range (where we perhaps pass zero in for a value that we do not wish to constrain) then I imagine that clk_set_ceiling_rate and clk_set_floor_rate will simply become a wrapper for that function. No harm having it both ways. If one way of doing things falls out of favor we can always cull it and update all the users. Regards, Mike