From mboxrd@z Thu Jan 1 00:00:00 1970 From: Archit Taneja Subject: Re: [RFC 2/4] ARM: dts: Add ctrl-core DT node for DRA7 Date: Mon, 21 Apr 2014 10:45:28 +0530 Message-ID: <5354A970.8040605@ti.com> References: <1397654063-8055-1-git-send-email-archit@ti.com> <1397654063-8055-2-git-send-email-archit@ti.com> <20140418171854.GJ5354@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from bear.ext.ti.com ([192.94.94.41]:41846 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751199AbaDUFQv (ORCPT ); Mon, 21 Apr 2014 01:16:51 -0400 In-Reply-To: <20140418171854.GJ5354@atomide.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Tony Lindgren Cc: t-kristo@ti.com, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org 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? Archit > > Depending what the range 0x4a002000 0x6d0 contains, you may > want to set it up as another syscon area. > > Regards, > > Tony From mboxrd@z Thu Jan 1 00:00:00 1970 From: archit@ti.com (Archit Taneja) Date: Mon, 21 Apr 2014 10:45:28 +0530 Subject: [RFC 2/4] ARM: dts: Add ctrl-core DT node for DRA7 In-Reply-To: <20140418171854.GJ5354@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> Message-ID: <5354A970.8040605@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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? Archit > > Depending what the range 0x4a002000 0x6d0 contains, you may > want to set it up as another syscon area. > > Regards, > > Tony