From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [RFC 3/8] mfd:syscon: Introduce claim/read/write/release APIs Date: Wed, 8 May 2013 21:48:10 +0200 Message-ID: <201305082148.10933.arnd@arndb.de> References: <1368022187-1633-1-git-send-email-srinivas.kandagatla@st.com> <201305081650.23264.arnd@arndb.de> <518A8C1D.3090600@st.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <518A8C1D.3090600-qxv4g6HH51o@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: srinivas.kandagatla-qxv4g6HH51o@public.gmane.org Cc: linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Viresh Kumar , Will Deacon , Jiri Slaby , Russell King , sameo-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, Nicolas Pitre , linux-serial-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jason Cooper , devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, Rob Herring , Stuart Menefy , Stephen Warren , dong.aisheng-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Greg Kroah-Hartman , Mark Brown , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-serial@vger.kernel.org On Wednesday 08 May 2013, Srinivas KANDAGATLA wrote: > the pinctrl driver calls syconf_claim(np, "st,alt-control) to get a > field and then do a read/write on the field. > > Just in pinctrl driver we use around 50-100 sysconf registers scatters > across different groups. > > Without these new APIs, its very difficult to pass this information to > the drivers. But are those necessarily things you would configure using DT? If there are so many registers that are shared between mutliple subsystems, maybe using drivers/mfd/syscon for that is taking things further than you should, since it is unlike what any of the other SoC families need from syscon. Can you describe how your syscon registers are laid out? Which subsystems beside pinctrl need to directly interact with it? Is there any logical structure in it or do you just have tons of bits scattered around an MMIO area? Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Wed, 8 May 2013 21:48:10 +0200 Subject: [RFC 3/8] mfd:syscon: Introduce claim/read/write/release APIs In-Reply-To: <518A8C1D.3090600@st.com> References: <1368022187-1633-1-git-send-email-srinivas.kandagatla@st.com> <201305081650.23264.arnd@arndb.de> <518A8C1D.3090600@st.com> Message-ID: <201305082148.10933.arnd@arndb.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wednesday 08 May 2013, Srinivas KANDAGATLA wrote: > the pinctrl driver calls syconf_claim(np, "st,alt-control) to get a > field and then do a read/write on the field. > > Just in pinctrl driver we use around 50-100 sysconf registers scatters > across different groups. > > Without these new APIs, its very difficult to pass this information to > the drivers. But are those necessarily things you would configure using DT? If there are so many registers that are shared between mutliple subsystems, maybe using drivers/mfd/syscon for that is taking things further than you should, since it is unlike what any of the other SoC families need from syscon. Can you describe how your syscon registers are laid out? Which subsystems beside pinctrl need to directly interact with it? Is there any logical structure in it or do you just have tons of bits scattered around an MMIO area? Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753994Ab3EHTsg (ORCPT ); Wed, 8 May 2013 15:48:36 -0400 Received: from moutng.kundenserver.de ([212.227.126.171]:62290 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750900Ab3EHTse (ORCPT ); Wed, 8 May 2013 15:48:34 -0400 From: Arnd Bergmann To: srinivas.kandagatla@st.com Subject: Re: [RFC 3/8] mfd:syscon: Introduce claim/read/write/release APIs Date: Wed, 8 May 2013 21:48:10 +0200 User-Agent: KMail/1.12.2 (Linux/3.8.0-18-generic; KDE/4.3.2; x86_64; ; ) Cc: dong.aisheng@linaro.org, sameo@linux.intel.com, Rob Landley , Grant Likely , Rob Herring , Russell King , Linus Walleij , "Greg Kroah-Hartman" , Jiri Slaby , Stuart Menefy , Shawn Guo , Olof Johansson , Jason Cooper , Stephen Warren , Maxime Ripard , Nicolas Pitre , Will Deacon , Dave Martin , Marc Zyngier , Viresh Kumar , Mark Brown , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, linux-serial@vger.kernel.org References: <1368022187-1633-1-git-send-email-srinivas.kandagatla@st.com> <201305081650.23264.arnd@arndb.de> <518A8C1D.3090600@st.com> In-Reply-To: <518A8C1D.3090600@st.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Message-Id: <201305082148.10933.arnd@arndb.de> X-Provags-ID: V02:K0:g8WINxm89xGqgFQiyf2Olm68b44TMxp7scISWosllyN q99vyr3n6Wc704bjtfWlkyjv9FLsUSJSWzpv8uX+uVoSdXY8xz DG/vV0tufdlucnrtxLBOCsrcO+XLh7qM7cDMkEbGjZ8DeOSuWT Oa+xLerOiAjX4PE2T0ud031+Rpy2zGg5PllqfULZp+vaNmZmmw gxwqH6bZRWnFJ5nRrQPpu8Izvigh/tPnuuS9b0GC/UDVaaLuJm xzOV9rPL/PMmcYFqwMJFfvZEhsdZ5RcriUWQHeM2rAOSa9bHvJ 1y99TvkfdD4o3Ug7815adpfbqF+F14l+ehuEUTs5qu/30gnLaj HArHcKiIuTFs4OSzSdDI= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 08 May 2013, Srinivas KANDAGATLA wrote: > the pinctrl driver calls syconf_claim(np, "st,alt-control) to get a > field and then do a read/write on the field. > > Just in pinctrl driver we use around 50-100 sysconf registers scatters > across different groups. > > Without these new APIs, its very difficult to pass this information to > the drivers. But are those necessarily things you would configure using DT? If there are so many registers that are shared between mutliple subsystems, maybe using drivers/mfd/syscon for that is taking things further than you should, since it is unlike what any of the other SoC families need from syscon. Can you describe how your syscon registers are laid out? Which subsystems beside pinctrl need to directly interact with it? Is there any logical structure in it or do you just have tons of bits scattered around an MMIO area? Arnd