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=ham 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 01683C43214 for ; Tue, 10 Aug 2021 14:19:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DC1D760F02 for ; Tue, 10 Aug 2021 14:19:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240970AbhHJOUB (ORCPT ); Tue, 10 Aug 2021 10:20:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:54656 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242675AbhHJOSF (ORCPT ); Tue, 10 Aug 2021 10:18:05 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9962A61158; Tue, 10 Aug 2021 14:16:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1628605004; bh=+SZmIis+xGQqa80afTUIFbXPIBLY3A8koq5bqvSl9xs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZJuSMFBBMj/JtZ1SV0493L3aP4iBcj4mO7rzVvgsxoYqY7sA3z76znihjEpabRK+c HnDF4KRy+G3PH8N+HxULgzDAgaU1D3DTV3xmryoz6bsLAH9SO4ftUaIx/hQlTI+vSO EctUX/QC3zxG/Xi8beU/VolLChIxAw+a3b1mp8mpzvbnpaY/CB7qkgmwxtXJIk6f55 Yt70OgqbSVStkZTobiuYED7FlfTDcYOw3c5fRytYCQmZOeSUjoyvdU/fozFzLBjeGx YbRpwybTIPfclIhjt+iv5LEw8JvcvKPkVLQdwoJPTqCajCHVb6LAnNBJcfKZgh8GBh Du0ddIydiod+w== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dave Gerlach , Kevin Hilman , Tony Lindgren , Sasha Levin , linux-omap@vger.kernel.org, devicetree@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 02/10] ARM: dts: am43x-epos-evm: Reduce i2c0 bus speed for tps65218 Date: Tue, 10 Aug 2021 10:16:33 -0400 Message-Id: <20210810141641.3118360-2-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210810141641.3118360-1-sashal@kernel.org> References: <20210810141641.3118360-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: devicetree@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 @@ &i2c0 { status = "okay"; pinctrl-names = "default"; pinctrl-0 = <&i2c0_pins>; - clock-frequency = <400000>; + clock-frequency = <100000>; tps65218: tps65218@24 { reg = <0x24>; -- 2.30.2