From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [RFC 2/4] ARM: dts: Add ctrl-core DT node for DRA7 Date: Mon, 21 Apr 2014 08:10:34 -0700 Message-ID: <20140421151034.GA23945@atomide.com> References: <1397654063-8055-1-git-send-email-archit@ti.com> <1397654063-8055-2-git-send-email-archit@ti.com> <20140418171854.GJ5354@atomide.com> <5354A970.8040605@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mho-03-ewr.mailhop.org ([204.13.248.66]:60838 "EHLO mho-01-ewr.mailhop.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751287AbaDUPKk (ORCPT ); Mon, 21 Apr 2014 11:10:40 -0400 Content-Disposition: inline In-Reply-To: <5354A970.8040605@ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Archit Taneja Cc: t-kristo@ti.com, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org * Archit Taneja [140420 22:16]: > Hi, > > On Friday 18 April 2014 10:48 PM, Tony Lindgren wrote: > >* Archit Taneja [140416 06:20]: > >>Add DT node for the ctrl-core sub module of the DRA7 control module. We map the > >>CTRL_MODULE_CORE address region up to 0x4a002d60, this region contains register > >>fields which configure clocks. The remainder of the registers are related to > >>pad configurations or cross-bar configurations, and therefore aren't mapped. > > > >Can you please check if this can just use the existing > >regmap syscon mapping: > > > >syscon = <&dra7_ctrl_general>; > > > >See how the drivers/regulator/pbias-regulator.c is using the > >syscon to initialize a regulator and then omap_hsmmc.c just does > >the standard regulator calls. > > The thing is that this bit needs to be set before the the DSS hwmods are > reset, and that happens very early. If we don't do this, DSS won't reset > properly, and not get back to an idle state. > > I am not sure where I can configure the syscon register early enough that it > happens before the hwmods are reset. With a syscon mapping, I guess we would > access the register when the DSS driver is probed. But that's too late for > us. > > Ideally, it would be much better to have a syscon mapping. Do you have any > suggestions how this can be achieved very early in boot? It's best to move the reset and initialization of DSS happen later. I believe we already are resetting only some of the hwmods early on. Regards, Tony