From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benoit Cousson Subject: Re: [PATCH] ARM: OMAP2+: timer: remove CONFIG_OMAP_32K_TIMER Date: Mon, 12 Nov 2012 12:01:00 +0100 Message-ID: <50A0D6EC.2040608@ti.com> References: <1352299344-8011-1-git-send-email-grinberg@compulab.co.il> <509AD478.1050904@ti.com> <509B666F.6080507@compulab.co.il> <509BFFDF.9040605@ti.com> <79CD15C6BA57404B839C016229A409A83EB68799@DBDE01.ent.ti.com> <509C050C.6010201@ti.com> <79CD15C6BA57404B839C016229A409A83EB71352@DBDE01.ent.ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from devils.ext.ti.com ([198.47.26.153]:33994 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751751Ab2KLLBX (ORCPT ); Mon, 12 Nov 2012 06:01:23 -0500 In-Reply-To: <79CD15C6BA57404B839C016229A409A83EB71352@DBDE01.ent.ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "Hiremath, Vaibhav" Cc: "Hunter, Jon" , Igor Grinberg , Tony Lindgren , "Hilman, Kevin" , Paul Walmsley , "linux-omap@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "Shilimkar, Santosh" Hi Vaibhav, On 11/12/2012 11:38 AM, Hiremath, Vaibhav wrote: > On Fri, Nov 09, 2012 at 00:46:28, Hunter, Jon wrote: >> >> On 11/08/2012 12:59 PM, Hiremath, Vaibhav wrote: >>> On Fri, Nov 09, 2012 at 00:24:23, Hunter, Jon wrote: >>>> >>>> On 11/08/2012 01:59 AM, Igor Grinberg wrote: >>>> >>>> [snip] >>>> >>>>> There is no reliable way to determine which source should be used in runtime >>>>> for boards that do not have the 32k oscillator wired. >>>> >>>> So thinking about this some more and given that we are moving away from >>>> board files, if a board does not provide a 32kHz clock source, then this >>>> should be reflected in the device-tree source file for that board. >>>> Hence, at boot time we should be able to determine if a 32kHz clock >>>> source can be used. >>>> >>> >>> Let me feed some more thoughts here :) >>> >>> The way it is being detected currently is based on timer idle status bit. >>> I am worried that, this is the only option we have. >> >> Why not use device-tree to indicate the presence of a 32k clock source? >> This seems like a board level configuration and so device-tree seems to >> be the perfect place for this IMO. >> > > I think I agree with you, but for this to happen in clean way, its time to > start populating clock-nodes in DT, don't you think? Something like, > > > clocks { > rtc_clk: clk@X { > compatible = "crystal-32k, per-32k, xyz"; > clock-frequency = <32768>; > }; > ... > }; > > Timer { > > ref-clock = <&rtc_clk>; > }; > > What do you think? That's indeed the proper way to do it, since this is a pure board level parameter and we do have the binding to express that. We just have to add that in the DTS:-) Regards, Benoit