From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753818AbaIALe0 (ORCPT ); Mon, 1 Sep 2014 07:34:26 -0400 Received: from mailout3.samsung.com ([203.254.224.33]:16860 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753536AbaIALeW (ORCPT ); Mon, 1 Sep 2014 07:34:22 -0400 X-AuditID: cbfee68d-f79c46d000000b84-99-540459bb972a From: Pankaj Dubey To: "'Arnd Bergmann'" , "'Lee Jones'" Cc: linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org, kgene.kim@samsung.com, linux@arm.linux.org.uk, vikas.sajjan@samsung.com, joshi@samsung.com, naushad@samsung.com, thomas.ab@samsung.com, chow.kim@samsung.com, "'Tomasz Figa'" , broonie@kernel.org References: <1408694991-21615-1-git-send-email-pankaj.dubey@samsung.com> <20140901074918.GB6226@lee--X1> <4121644.3haxjiIdIo@wuerfel> In-reply-to: <4121644.3haxjiIdIo@wuerfel> Subject: RE: [PATCH] mfd: syscon: Decouple syscon interface from syscon devices Date: Mon, 01 Sep 2014 17:05:33 +0530 Message-id: <000c01cfc5d9$03866c30$0a934490$@samsung.com> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7bit X-Mailer: Microsoft Outlook 14.0 Thread-index: AQHpa/2m/d4/OY0ITARCUM8RI+G5jQGj941vAnXmlLmbmAms0A== Content-language: en-us X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrPIsWRmVeSWpSXmKPExsWyRsSkSnd3JEuIwbJpVhZ/Jx1jt5j68Amb xbJJd9ksvu/6wm7Ru+Aqm8X9r0cZLTY9vsZqcXnXHDaLGef3MVncvsxr8enof1aL9TNes1h0 LGO0uPlsO5MDn0dLcw+bx+9fkxg9Nq3qZPO4c20Pm8fmJfUefVtWMXp83iQXwB7FZZOSmpNZ llqkb5fAlXFmnV5Bv1jF1c5fTA2MPwW7GDk4JARMJJ521nUxcgKZYhIX7q1nA7GFBJYySpw5 rgERN5F49+glK0R8OqPE1CVBXYxcQPZfRomzR/pYQBJsAroST97PZQaxRQTcJS603WMCKWIW OM4ksez1f3aI7nZGie69HCA2p4CmxPavexhBbGEBf4kv9xaDNbMIqErsOtYHto1XwFLi8cnn jBC2oMSPyffAljELaEms33mcCcKWl9i85i0zxKUKEjvOvmaEOMJJ4trHP8wQNeISkx48ZAc5 SEJgKYfE1e/ToZYJSHybfIgFEhKyEpsOQM2RlDi44gbLBEaJWUhWz0KyehaS1bOQrFjAyLKK UTS1ILmgOCm9yFCvODG3uDQvXS85P3cTIzAdnP73rHcH4+0D1ocYBTgYlXh4H8xiDhFiTSwr rsw9xGgKdNFEZinR5Hxg0skriTc0NjOyMDUxNTYytzRTEudVlPoZLCSQnliSmp2aWpBaFF9U mpNafIiRiYNTqoFx1qucd37f1oSVbrEqePJvx9GQNb8i94sGf1p9fC/L5NlNt/i3326o+v/T /HrVzGyvf9Vcggd+igs9NuTtPVWiX+DBEDbHi+2G0vpv6dwvfsXcYVmb57IoYKHmottndOyX dKsprP4wn1d95mN1lyX/J7DfWzCF1a+Oi1tMh2/f0y9Lfx/bXeu7Q4mlOCPRUIu5qDgRAOkV 7FsCAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrNKsWRmVeSWpSXmKPExsVy+t9jQd3dkSwhBpuuG1j8nXSM3WLqwyds Fssm3WWz+L7rC7tF74KrbBb3vx5ltNj0+BqrxeVdc9gsZpzfx2Rx+zKvxaej/1kt1s94zWLR sYzR4uaz7UwOfB4tzT1sHr9/TWL02LSqk83jzrU9bB6bl9R79G1ZxejxeZNcAHtUA6NNRmpi SmqRQmpecn5KZl66rZJ3cLxzvKmZgaGuoaWFuZJCXmJuqq2Si0+ArltmDtDFSgpliTmlQKGA xOJiJX07TBNCQ9x0LWAaI3R9Q4LgeowM0EDCGsaMM+v0CvrFKq52/mJqYPwp2MXIySEhYCLx 7tFLVghbTOLCvfVsILaQwHRGialLgroYuYDsv4wSZ4/0sYAk2AR0JZ68n8sMYosIuEtcaLvH BFLELHCcSWLZ6//sEN3tjBLdezlAbE4BTYntX/cwgtjCAv4SX+4tBmtmEVCV2HWsD2wzr4Cl xOOTzxkhbEGJH5PvgS1jFtCSWL/zOBOELS+xec1bZohLFSR2nH3NCHGEk8S1j3+YIWrEJSY9 eMg+gVFoFpJRs5CMmoVk1CwkLQsYWVYxiqYWJBcUJ6XnGuoVJ+YWl+al6yXn525iBCecZ1I7 GFc2WBxiFOBgVOLhfTCLOUSINbGsuDL3EKMEB7OSCO/0UJYQId6UxMqq1KL8+KLSnNTiQ4ym QJ9OZJYSTc4HJsO8knhDYxNzU2NTSxMLEzNLJXHeA63WgUIC6YklqdmpqQWpRTB9TBycUg2M Rtv5hb9N18s6b/d9ieOkzOPl6n5NNfd/LE4QfXpFxV5wWo+Mx6YdwQs+bKspmf+77YT1EsmF fbs2+rAwx3lZKk8zuzjZNseZqywzK4qhJe3BSRM3w2qtD5U7Q6fJHXM8rd6rKD257fqEwAOC Plr3vr3b93HarJlyJ3fpvH95otw47axOpQWLEktxRqKhFnNRcSIAH/D+7k4DAAA= DLP-Filter: Pass X-MTR: 20000000000000000@CPGS X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Arnd, > -----Original Message----- > From: Arnd Bergmann [mailto:arnd@arndb.de] > Sent: Monday, September 01, 2014 4:07 PM > To: Lee Jones > Cc: Pankaj Dubey; linux-arm-kernel@lists.infradead.org; linux-samsung- > soc@vger.kernel.org; linux-kernel@vger.kernel.org; kgene.kim@samsung.com; > linux@arm.linux.org.uk; vikas.sajjan@samsung.com; joshi@samsung.com; > naushad@samsung.com; thomas.ab@samsung.com; chow.kim@samsung.com; > Tomasz Figa; broonie@kernel.org > Subject: Re: [PATCH] mfd: syscon: Decouple syscon interface from syscon devices > > On Monday 01 September 2014 08:49:18 Lee Jones wrote: > > On Fri, 22 Aug 2014, Pankaj Dubey wrote: > > > > > From: Tomasz Figa > > > > > > Currently a syscon entity can be only registered directly through a > > > platform device that binds to a dedicated driver. However in certain > > > use cases it is desirable to make a device used with another driver > > > a syscon interface provider. For example, certain SoCs (e.g. Exynos) > > > contain system controller blocks which perform various functions > > > such as power domain control, CPU power management, low power mode > > > control, but in addition contain certain IP integration glue, such > > > as various signal masks, coprocessor power control, etc. In such > > > case, there is a need to have a dedicated driver for such system > > > controller but also share registers with other drivers. The latter > > > is where the syscon interface is helpful. > > > > > > This patch decouples syscon object from syscon driver, so that it > > > can be registered from any driver in addition to the original > > > "syscon" platform driver. > > > > > > Signed-off-by: Tomasz Figa > > > Signed-off-by: Pankaj Dubey > > > --- > > > > > > RFC patch [1] was posted by Tomasz Figa. This patch addresses some > > > of comments given by Arnd to RFC patch, and further decouples syscon > > > from device model. It also gives flexibility of registering with > > > syscon at early stage using device_node object. > > > > It would be helpful if Arnd gave this revision his blessing (Ack). > > I never saw a reason why we don't take this all the way as discussed a few times: > Completely remove the dependency of syscon on having a platform driver for it, and > make it possible to just call > syscon_regmap_lookup_by_phandle() without having to register it first. > Please have a look at this thread [1], where we discussed the need of syscon as platform device. Looks like still there are users of syscon_regmap_lookup_by_pdevname (clps711x.c). So we can't make it completely independent of platform_device. [1] https://www.mail-archive.com/linux-samsung-soc@vger.kernel.org/msg35708.html > Arnd