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 268B4C4320A for ; Tue, 24 Aug 2021 17:40:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0F71B61245 for ; Tue, 24 Aug 2021 17:40:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242104AbhHXRlh (ORCPT ); Tue, 24 Aug 2021 13:41:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:45136 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241289AbhHXRif (ORCPT ); Tue, 24 Aug 2021 13:38:35 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6E4D061BFC; Tue, 24 Aug 2021 17:08:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629824881; bh=LivMo73117MtVQQLmxNYoM6hSBv5PnvQPonsUm8se1o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WPgECgNldFCBJI8j4yqETDrBnKJ6n0+98cCAiYHDGzxaePdtvALJ+iBm23YQYUo9/ Y5bvY6lDe+/sJHzrMvpWKt1hiu9ETGWdj/AoomeipeFew2BP3SvJh+ynSiQAqKrlt0 Q69BAVvYIKhPDKVr5ctfXADR+5CXmOuWkVeeP/CWVrpauPeGeBorc4wjC1XCSST5n8 x9ptTBV1jswU58QZOHgzFqMMwcVt8JLMq0nXRI3jwsOACQtH+ipZ/3KY/ukCfVDTAd ceB1Oo8i2iu1PMTX8YuXTKdPk4Uxuly6oUg/uyVRtitkmOgUU/C8H2S285bdWz+z+E W5XlJBu2TqnXw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dave Gerlach , Kevin Hilman , Tony Lindgren , Sasha Levin Subject: [PATCH 4.4 17/31] ARM: dts: am43x-epos-evm: Reduce i2c0 bus speed for tps65218 Date: Tue, 24 Aug 2021 13:07:29 -0400 Message-Id: <20210824170743.710957-18-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210824170743.710957-1-sashal@kernel.org> References: <20210824170743.710957-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.4.282-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.4.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.4.282-rc1 X-KernelTest-Deadline: 2021-08-26T17:07+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 a74b09f17a1a..e7cd99793bc6 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