From patchwork Thu Jul 25 09:45:40 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gregory CLEMENT X-Patchwork-Id: 11058355 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5970813A0 for ; Thu, 25 Jul 2019 09:46:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 49D502893F for ; Thu, 25 Jul 2019 09:46:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3E0882899C; Thu, 25 Jul 2019 09:46:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C2DB82893F for ; Thu, 25 Jul 2019 09:46:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729018AbfGYJp7 (ORCPT ); Thu, 25 Jul 2019 05:45:59 -0400 Received: from relay7-d.mail.gandi.net ([217.70.183.200]:49557 "EHLO relay7-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728748AbfGYJp6 (ORCPT ); Thu, 25 Jul 2019 05:45:58 -0400 X-Originating-IP: 92.137.69.152 Received: from localhost (alyon-656-1-672-152.w92-137.abo.wanadoo.fr [92.137.69.152]) (Authenticated sender: gregory.clement@bootlin.com) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id DE75820008; Thu, 25 Jul 2019 09:45:55 +0000 (UTC) From: Gregory CLEMENT To: Liam Girdwood , Mark Brown , linux-kernel@vger.kernel.org Cc: Rob Herring , devicetree@vger.kernel.org, Tony Lindgren , linux-omap@vger.kernel.org, Thomas Petazzoni , Gregory CLEMENT Subject: [PATCH 1/3] dt-bindings: regulator: twl6030: Add retain-on-reset property Date: Thu, 25 Jul 2019 11:45:40 +0200 Message-Id: <20190725094542.16547-2-gregory.clement@bootlin.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190725094542.16547-1-gregory.clement@bootlin.com> References: <20190725094542.16547-1-gregory.clement@bootlin.com> MIME-Version: 1.0 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP During reset the VMMC regulator doesn't reach 0V and only drops to 1.8V, furthermore the pulse width is under 200us whereas the SD specification expect 1ms. For this 2 reasons being able to no reset at all the VMMC during warm reset and keep the current voltage is a good workaround. The TWL6030 allows this but needs to be aware of it and this configuration should also be shared with the bootloader. This is the purpose of this new property: ti,retain-on-reset Signed-off-by: Gregory CLEMENT --- .../devicetree/bindings/regulator/twl-regulator.txt | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/Documentation/devicetree/bindings/regulator/twl-regulator.txt b/Documentation/devicetree/bindings/regulator/twl-regulator.txt index 74a91c4f8530..549f80436deb 100644 --- a/Documentation/devicetree/bindings/regulator/twl-regulator.txt +++ b/Documentation/devicetree/bindings/regulator/twl-regulator.txt @@ -71,3 +71,10 @@ Example: regulator-min-microvolt = <1000000>; regulator-max-microvolt = <3000000>; }; + +For twl6030 regulators/LDOs: + + - ti,retain-on-reset: Does not turn off the supplies during warm + reset. Could be needed for VMMC, as TWL6030 + reset sequence for this signal does not comply + with the SD specification.