From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755443AbeDWOeE (ORCPT ); Mon, 23 Apr 2018 10:34:04 -0400 Received: from mailout2.w1.samsung.com ([210.118.77.12]:36774 "EHLO mailout2.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754962AbeDWOeA (ORCPT ); Mon, 23 Apr 2018 10:34:00 -0400 DKIM-Filter: OpenDKIM Filter v2.11.0 mailout2.w1.samsung.com 20180423143357euoutp02958ae2ee684715b19546da9d2709b15f~oF0ATcJOI2202422024euoutp02c X-AuditID: cbfec7f2-5ffe19c000011644-a0-5addeed240c5 From: Maciej Purski To: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Cc: Mark Brown , Fabio Estevam , Tony Lindgren , Liam Girdwood , Rob Herring , Mark Rutland , Marek Szyprowski , Doug Anderson , Bartlomiej Zolnierkiewicz , Maciej Purski Subject: [PATCH v7 0/6] Add coupled regulators mechanism Date: Mon, 23 Apr 2018 16:33:36 +0200 Message-id: <1524494022-22260-1-git-send-email-m.purski@samsung.com> X-Mailer: git-send-email 2.7.4 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrJIsWRmVeSWpSXmKPExsWy7djP87qX3t2NMjg0Tc9i44z1rBZTHz5h s5h/5ByrxdllB9ksHl71t/h2pYPJ4vKuOWwWC17eYrFYe+Quu8XS6xeZLFr3HmG32H/Fy4HH Y828NYwe375OYvGY3XCRxWPnrLvsHptWdbJ59G1ZxejxeZNcAHsUl01Kak5mWWqRvl0CV8aN rz+YCq7KV1w6vYu1gbFFsouRk0NCwERi5tTDjF2MXBxCAisYJbp+z2SFcD4zSixbcYsdpqrl x1omiMQyRonN3w5AVf1nlPj77BlQFQcHm4CWxJr2eJAGEQEbibc3DoCNZRboZ5aY3NTKApIQ FrCQWHl+GjOIzSKgKrHjXw8riM0r4CJx/M1rFohtchI3z3UygzRLCMxhk+ieOZURIuEiMWX5 LmYIW1ji1fEtUOfJSFye3A3VXC1x8esuNgi7RqLx9gaoGmuJz5O2gPUyC/BJTNo2nRnkaAkB XomONiGIEg+J99umQ5U7Shy79QDMFhKIlXjb2sMygVFyASPDKkbx1NLi3PTUYsO81HK94sTc 4tK8dL3k/NxNjMAIPv3v+KcdjF8vJR1iFOBgVOLh3aF7N0qINbGsuDL3EKMEB7OSCO/DN0Ah 3pTEyqrUovz4otKc1OJDjNIcLErivHEadVFCAumJJanZqakFqUUwWSYOTqkGxubUPrcV3FWr tbYsS9x65tWla66vJOWzPC63Fqifusc9//B526qqLzrreh9e36ndGXM4oSVtVvYVpePrPbaL /etxuFbQUs7fz7urallu0e/vW1VYtkXF9p6yF8tt1A1Nnx6+5uinplO77HLvLOsRsr35WML1 uO4acxvBmZ6fr6zYdHvbfNNOcyWW4oxEQy3mouJEADkg6lTcAgAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprALMWRmVeSWpSXmKPExsVy+t/xy7oX392NMvjQpGSxccZ6VoupD5+w Wcw/co7V4uyyg2wWD6/6W3y70sFkcXnXHDaLBS9vsVisPXKX3WLp9YtMFq17j7Bb7L/i5cDj sWbeGkaPb18nsXjMbrjI4rFz1l12j02rOtk8+rasYvT4vEkugD2KyyYlNSezLLVI3y6BK+PG 1x9MBVflKy6d3sXawNgi2cXIySEhYCLR8mMtUxcjF4eQwBJGiV+vXrNDOI1MEp92/QdyODjY BLQk1rTHgzSICNhIvL1xgBGkhllgIrPEwsVXWEESwgIWEivPT2MGsVkEVCV2/OsBi/MKuEgc f/OaBWKbnMTNc53MExi5FjAyrGIUSS0tzk3PLTbSK07MLS7NS9dLzs/dxAgMp23Hfm7Zwdj1 LvgQowAHoxIP7w7du1FCrIllxZW5hxglOJiVRHgfvgEK8aYkVlalFuXHF5XmpBYfYpTmYFES 5z1vUBklJJCeWJKanZpakFoEk2Xi4JRqYGyfzTh5b1BF6nGzDbVfnF/r2PR3hSUtNalou7VS 0u5hUPQZFvldZsVXli/cLmTGnmRUNvHEmuxpIYrL1WdN+vg69X3UT80wXmnmavVDJfyTxbSn zMrwrrgTq7fviumm27xHviemHQ+f5D5d9UBg8Oakoqagn5ZVq68HPbh3NseSu/GWiOKyk0os xRmJhlrMRcWJAJDpdNAjAgAA X-CMS-MailID: 20180423143353eucas1p1d417b5995e380f6a7b168a98a76ecf40 X-Msg-Generator: CA CMS-TYPE: 201P X-CMS-RootMailID: 20180423143353eucas1p1d417b5995e380f6a7b168a98a76ecf40 X-RootMTR: 20180423143353eucas1p1d417b5995e380f6a7b168a98a76ecf40 References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi all, this patchset adds a new mechanism to the framework - regulators' coupling. On Odroid XU3/4 and other Exynos5422 based boards there is a case, that different devices on the board are supplied by different regulators with non-fixed voltages. If one of these devices temporarily requires higher voltage, there might occur a situation that the spread between devices' voltages is so high, that there is a risk of changing 'high' and 'low' states on the interconnection between devices powered by those regulators. Algorithmicaly the problem was solved by: Inderpal Singh Doug Anderson The discussion on that subject can be found here: https://lkml.org/lkml/2014/4/29/28 Therefore this patchset is an attempt to apply the idea to regulators core as concluded in the discussion by Mark Brown and Doug Anderson. This feature is required to enable support for generic CPUfreq and devfreq drivers for the mentioned boards. The current assumption is that an uncoupled regulator is a special case of a coupled one, so they should share a common voltage setting path. The previous version caused locking problems on some boards. The discussion can be found here: https://lkml.org/lkml/2018/3/5/965 Current idea, which should solve the locking issues is making it possible to try to lock a mutex multiple times by a single task just like it is done in clk/clk.c. This should handle all possible coupling-supply combinations except coupling with a supply. The previous patchset should have fixed the locking issue encountered by Fabio, but unfortunately it hasn't fixed Tony's problems with mmc. I hope this patch fixes it, as the regulator enable path should remain the same. I'd be very grateful for any feedback from Fabio Estevam or Tony Lindgren. Best regards, Maciej Purski --- Changes in v7: - do not call regulator_balance_voltage(), when enabling a non-coupled regulator - rebase against linux-next 20180423 Changes in v6: - change locking model - fix build errors on non-of architectures - update bindings Changes in v5: - rebase against current Mark Brown's regulators next Changes in v4: - make paths for coupled and uncoupled regulators common - coupling descriptors are now always present in regulator_dev - fail to probe if data inconsistency is detected - retry to resolve coupling regultors in late init call - rebase on top of linux-next 20180119 - fix commit messages - split patches to make the patchset easier to review Changes in v3: - move dts parsing code to of_regulator.c, in order to the so, add a new commit in which of_regulator_find_by_node() is moved to of_regulator.c as well - improve error messages - move max_spread variable to constraints - perform resolving of coupled regulators under a list mutex - remove useless locking functions - some minor refactorization - improve commit messages Changes in RFC v2: - allow coupling n regulators (in fact up to constant value, now set to 10) - change algorithm to be more readable - introduce better locking - add more comments - split first patch into two - update commit messages - change sequence of the patches Maciej Purski (6): regulator: core: Make locks re-entrant regulator: bindings: Add properties for coupled regulators regulator: core: Parse coupled regulators properties regulator: core: Resolve coupled regulators regulator: core: Add voltage balancing mechanism regulator: core: Change voltage setting path .../devicetree/bindings/regulator/regulator.txt | 5 + drivers/regulator/core.c | 553 ++++++++++++++++++--- drivers/regulator/internal.h | 28 +- drivers/regulator/of_regulator.c | 151 ++++++ include/linux/regulator/driver.h | 20 + include/linux/regulator/machine.h | 4 + 6 files changed, 681 insertions(+), 80 deletions(-) -- 2.7.4