From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F924C4338F for ; Tue, 24 Aug 2021 17:32:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EB707610E8 for ; Tue, 24 Aug 2021 17:32:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241465AbhHXRc7 (ORCPT ); Tue, 24 Aug 2021 13:32:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:35160 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239733AbhHXRaD (ORCPT ); Tue, 24 Aug 2021 13:30:03 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8CF5561B48; Tue, 24 Aug 2021 17:05:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629824737; bh=TmRaknQ/+uPAoF/VnGCfCnrkIPRMKcViO2PEo6DbAVQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V80vRkHzUq72xXZXb+AEXq01nnu1mDag4DQT58Vp83MVieqJfDRTSGgWZ5MJx859u 3ApAwOh44hIxdg/X1qiKE0xlJGg7vZp0YeixFQqH9nWOdQaCdLSRT3cnJjTz+c+RWF YjWPw8k7kFwxQqlgFJXLgqS8PS0jkOlA5jWomj/1hGhrdFLNXhzfrfipVrOKciAhxH dWexd6aPTYxejIZcyB1KjJzNS/DnMxpQj8WcYrp/KJIawmn07nib0Q7upqQavX2Ez6 pz2ib6synx1j5zXT15qAvx2fWCKPzQBtasJfoMgcyR83Yrv2zWqt2ctaoTLl/+zh6U pVM8VqKY8OlrA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dave Gerlach , Kevin Hilman , Tony Lindgren , Sasha Levin Subject: [PATCH 4.14 40/64] ARM: dts: am43x-epos-evm: Reduce i2c0 bus speed for tps65218 Date: Tue, 24 Aug 2021 13:04:33 -0400 Message-Id: <20210824170457.710623-41-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210824170457.710623-1-sashal@kernel.org> References: <20210824170457.710623-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.14.245-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.14.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.14.245-rc1 X-KernelTest-Deadline: 2021-08-26T17:04+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dave Gerlach [ Upstream commit 20a6b3fd8e2e2c063b25fbf2ee74d86b898e5087 ] Based on the latest timing specifications for the TPS65218 from the data sheet, http://www.ti.com/lit/ds/symlink/tps65218.pdf, document SLDS206 from November 2014, we must change the i2c bus speed to better fit within the minimum high SCL time required for proper i2c transfer. When running at 400khz, measurements show that SCL spends 0.8125 uS/1.666 uS high/low which violates the requirement for minimum high period of SCL provided in datasheet Table 7.6 which is 1 uS. Switching to 100khz gives us 5 uS/5 uS high/low which both fall above the minimum given values for 100 khz, 4.0 uS/4.7 uS high/low. Without this patch occasionally a voltage set operation from the kernel will appear to have worked but the actual voltage reflected on the PMIC will not have updated, causing problems especially with cpufreq that may update to a higher OPP without actually raising the voltage on DCDC2, leading to a hang. Signed-off-by: Dave Gerlach Signed-off-by: Kevin Hilman Signed-off-by: Tony Lindgren Signed-off-by: Sasha Levin --- arch/arm/boot/dts/am43x-epos-evm.dts | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/boot/dts/am43x-epos-evm.dts b/arch/arm/boot/dts/am43x-epos-evm.dts index c4279b0b9f12..437e8d2dcc70 100644 --- a/arch/arm/boot/dts/am43x-epos-evm.dts +++ b/arch/arm/boot/dts/am43x-epos-evm.dts @@ -411,7 +411,7 @@ status = "okay"; pinctrl-names = "default"; pinctrl-0 = <&i2c0_pins>; - clock-frequency = <400000>; + clock-frequency = <100000>; tps65218: tps65218@24 { reg = <0x24>; -- 2.30.2