From patchwork Tue Dec 11 15:17:09 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Priit Laes X-Patchwork-Id: 10724017 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 CC08791E for ; Tue, 11 Dec 2018 15:19:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B8D982B2CA for ; Tue, 11 Dec 2018 15:19:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AAA5A2B2D0; Tue, 11 Dec 2018 15:19:57 +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=-4.4 required=2.0 tests=BAYES_00,DKIM_ADSP_ALL, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 84DAA2B2CA for ; Tue, 11 Dec 2018 15:19:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=sm+S3FNq+J/zqjjc9VBzn+2hJbQID64EEu03vXNx4ls=; b=Z8Qq01mx4GN5U2 z6rNMRnabFsV1zrOzQDTv0MzwMLd7xaWkLD4//FtsG5yYduEzEtCcQO+iH3WX2AE+0nFub/+SjqcG Znb4lO+VeuCt9cm5wW3In54c7kHt+kdMg9CKWkC4WWXYTSHxqe0OR22vnn4IusIX1uQstukXkjzDE /vhjmqE/Eh36vxkQG/UUezT7/Fmn/nnrsDTE26on/2dIarrdQjcnLeqIhh5jSMAKxMHkffEoq/pnt A23jQru6HNbxJcU5uP9dNjKohND6+l4JfNdHIWCCaqndDBklXQVKkmGcWZ810/33hFbJT4Kd+Czy2 x+GrQk2IFcJO6A8TEvgA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gWjpA-0004tY-F8; Tue, 11 Dec 2018 15:19:52 +0000 Received: from plaes.org ([188.166.43.21]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gWjne-0003EL-8D for linux-arm-kernel@lists.infradead.org; Tue, 11 Dec 2018 15:18:26 +0000 Received: from localhost (unknown [213.204.46.240]) by plaes.org (Postfix) with ESMTPSA id 5DE9541289; Tue, 11 Dec 2018 15:17:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=plaes.org; s=mail; t=1544541441; bh=snlyZLidIJEaCnhVA6nQ3LGjhvn8FydspTFdTImmP0M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=c7MgmDx9DJLinzSnvgYeehR6oxBBjhN6sfII3g77a3+YcmFKIc2+DW71ABMJ7XZBO BPyrnGgsqFnp9MLtW3O21DWnFNhpW9CvtFyJJfy5xuVGqkhRPYUlG0PhMPrcNEOtTd 77rquDIP6CxjtiV6wfRbaLYrGrBr0LBRjeXw4Z3q6Nf6EBb8eN7A8rZ8rQaw9q72Cl 6UlrmOkbXazg76Hmym3D5tz0VVWkX1pHHBGYyQ+bJbJo4OidLk6InKxMWM5Avcs1Um KBlNg7Pnb+sTv6a3QT+6baskHeCOqaJT5k4JrEDAFC19kwfr5Gnu1CrSOM/LWrdf0E R7dxb9fA+W2ig== From: Priit Laes To: Lee Jones , Rob Herring , Mark Rutland , Chen-Yu Tsai , Maxime Ripard , Liam Girdwood , Mark Brown , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Olliver Schinagl , linux-sunxi Subject: [PATCH v2 5/8] dt-bindings: mfd: axp20x: Add software based soft_start for AXP209 LDO3 Date: Tue, 11 Dec 2018 17:17:09 +0200 Message-Id: <25e67fe9b5397aa5f11bdd7026e4ae6be51dd18b.1544512919.git-series.plaes@plaes.org> X-Mailer: git-send-email 2.19.2 In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181211_071819_064779_0A400320 X-CRM114-Status: GOOD ( 10.37 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Priit Laes Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP From: Olliver Schinagl In the past, there have been words on various lists that if LDO3 is disabled in u-boot, but enabled in the DTS, the axp209 driver would fail to continue/hang. Several enable/disable patches have been issues to devicetree's in both the kernel and u-boot to address this issue. What really happened however, was that the AXP209 shuts down without a notice and without setting an interrupt. This is caused when LDO3 gets overloaded, for example with large capacitors on the LDO3 output. Normally, we would expect that AXP209 would source 200 mA as per datasheet and set and trigger an interrupt when being overloaded. For some reason however, this does not happen. As a work-around, implement software-based 'regulator-soft-start' property for AXP209 LDO3 regulator, which is used to first bring up the LDO3 to the lowest possible voltage and then enable the LDO. After that, we can set the requested voltage as usual. Combining this setting with the regulator-ramp-delay allows LDO3 to come up slowly and staggered, potentially reducing overall inrush current. Signed-off-by: Olliver Schinagl Signed-off-by: Priit Laes --- Documentation/devicetree/bindings/mfd/axp20x.txt | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Documentation/devicetree/bindings/mfd/axp20x.txt b/Documentation/devicetree/bindings/mfd/axp20x.txt index c626605..2af4ff9 100644 --- a/Documentation/devicetree/bindings/mfd/axp20x.txt +++ b/Documentation/devicetree/bindings/mfd/axp20x.txt @@ -37,6 +37,9 @@ more information: - regulator-ramp-delay: sets the ramp up delay in uV/us AXP20x/DCDC2: 1600, 800 AXP20x/LDO3: 1600, 800 +- regulator-soft-start: enable the output at the lowest possible voltage and + only then set the desired voltage + AXP20x/LDO3: software-based implementation Optional properties: - x-powers,dcdc-freq: defines the work frequency of DC-DC in KHz