From patchwork Mon Apr 1 23:29:29 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Vasut X-Patchwork-Id: 2373391 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id E0AA93FD40 for ; Mon, 1 Apr 2013 23:32:27 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UMoAY-0002Bb-HR; Mon, 01 Apr 2013 23:29:42 +0000 Received: from mail-out.m-online.net ([2001:a60:0:28:0:1:25:1]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UMoAT-00028p-V0 for linux-arm-kernel@lists.infradead.org; Mon, 01 Apr 2013 23:29:38 +0000 Received: from frontend1.mail.m-online.net (frontend1.mail.intern.m-online.net [192.168.8.180]) by mail-out.m-online.net (Postfix) with ESMTP id 3ZfqWz2wq7z3hhl9; Tue, 2 Apr 2013 01:29:35 +0200 (CEST) X-Auth-Info: eA/NBT1t8kYrv31ns0GqVbPpfjq18UbEDQWdebY/UoQ= Received: from mashiro.lan (unknown [195.140.253.167]) by smtp-auth.mnet-online.de (Postfix) with ESMTPA id 3ZfqWz1MT6zbc6m; Tue, 2 Apr 2013 01:29:35 +0200 (CEST) From: Marek Vasut To: linux-arm-kernel@lists.infradead.org Subject: [PATCH] ARM: mxs: Slow down the I2C clock speed Date: Tue, 2 Apr 2013 01:29:29 +0200 Message-Id: <1364858969-17745-1-git-send-email-marex@denx.de> X-Mailer: git-send-email 1.7.10.4 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130401_192938_152110_27396FF4 X-CRM114-Status: GOOD ( 10.02 ) X-Spam-Score: -1.9 (-) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-1.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Marek Vasut , Fabio Estevam , Shawn Guo , linux-i2c@vger.kernel.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Slow down the I2C clock speed on M28 and SPS1 as it turns out the I2C block in i.MX28 can not operate stable enough with the bus running at 400kHz. Note that the driver used by Freescale runs the bus at 250kHz when 400kHz speed is selected, but the mainline Linux kernel runs the bus at actual 400kHz and that's where it is occasionally unstable. Play safe and run the bus at 100kHz. Signed-off-by: Marek Vasut Cc: Fabio Estevam Cc: Shawn Guo --- arch/arm/boot/dts/imx28-m28evk.dts | 1 - arch/arm/boot/dts/imx28-sps1.dts | 1 - 2 files changed, 2 deletions(-) diff --git a/arch/arm/boot/dts/imx28-m28evk.dts b/arch/arm/boot/dts/imx28-m28evk.dts index 5f0ba99..5aa44e0 100644 --- a/arch/arm/boot/dts/imx28-m28evk.dts +++ b/arch/arm/boot/dts/imx28-m28evk.dts @@ -177,7 +177,6 @@ i2c0: i2c@80058000 { pinctrl-names = "default"; pinctrl-0 = <&i2c0_pins_a>; - clock-frequency = <400000>; status = "okay"; sgtl5000: codec@0a { diff --git a/arch/arm/boot/dts/imx28-sps1.dts b/arch/arm/boot/dts/imx28-sps1.dts index e6cde8a..6c6a544 100644 --- a/arch/arm/boot/dts/imx28-sps1.dts +++ b/arch/arm/boot/dts/imx28-sps1.dts @@ -70,7 +70,6 @@ i2c0: i2c@80058000 { pinctrl-names = "default"; pinctrl-0 = <&i2c0_pins_a>; - clock-frequency = <400000>; status = "okay"; rtc: rtc@51 {