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=-9.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 20207C65BAE for ; Thu, 13 Dec 2018 04:32:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D18A620879 for ; Thu, 13 Dec 2018 04:32:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544675528; bh=Fbreh+Pfju7J2aX8+cIBYG7Wo3PHBgAYxf3fpn0Ea40=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=MU9EuYxxDA98DJzq/T8E09gsZY1PE7/bGm93Xfjxv2ExGWFPhX8JITJE8UWhXkm+P mRS9XjgNb3Yw/VnJ46IDD4iwIQbAxnhwfSdb7KACUzk4GP97FWjtpiDGJyeKXuRew7 quvFqBGY7fOBnvpXXwxAztUd3atpXtS/UZ/nefsI= DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D18A620879 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728978AbeLMEcG (ORCPT ); Wed, 12 Dec 2018 23:32:06 -0500 Received: from mail.kernel.org ([198.145.29.99]:44884 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728924AbeLMEb5 (ORCPT ); Wed, 12 Dec 2018 23:31:57 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8215820879; Thu, 13 Dec 2018 04:31:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544675517; bh=Fbreh+Pfju7J2aX8+cIBYG7Wo3PHBgAYxf3fpn0Ea40=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BHXJXET+BVNrDkEpj/EwmvakftDz6b1RCEJgaBkdcycgotJuNPRQkBbZIr2VnFLIq jSKkyfLC1FKu+h9helaiiroz4TEZIrzR2v9E25Vu2zEDxUUveawMLd1u+9HgAhXmuE KoWHkcJ0ieqKYC4XuU+RdHrWOuKLsF4FCfG4BWJg= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Masahiro Yamada , Wolfram Sang , Sasha Levin , linux-i2c@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 39/41] i2c: uniphier-f: fix violation of tLOW requirement for Fast-mode Date: Wed, 12 Dec 2018 23:30:52 -0500 Message-Id: <20181213043054.75891-39-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181213043054.75891-1-sashal@kernel.org> References: <20181213043054.75891-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Masahiro Yamada [ Upstream commit ece27a337d42a3197935711997f2880f0957ed7e ] Currently, the clock duty is set as tLOW/tHIGH = 1/1. For Fast-mode, tLOW is set to 1.25 us while the I2C spec requires tLOW >= 1.3 us. tLOW/tHIGH = 5/4 would meet both Standard-mode and Fast-mode: Standard-mode: tLOW = 5.56 us, tHIGH = 4.44 us Fast-mode: tLOW = 1.39 us, tHIGH = 1.11 us Signed-off-by: Masahiro Yamada Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/busses/i2c-uniphier-f.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-uniphier-f.c b/drivers/i2c/busses/i2c-uniphier-f.c index a403e8579b65..bc26ec822e26 100644 --- a/drivers/i2c/busses/i2c-uniphier-f.c +++ b/drivers/i2c/busses/i2c-uniphier-f.c @@ -470,9 +470,26 @@ static void uniphier_fi2c_hw_init(struct uniphier_fi2c_priv *priv) uniphier_fi2c_reset(priv); + /* + * Standard-mode: tLOW + tHIGH = 10 us + * Fast-mode: tLOW + tHIGH = 2.5 us + */ writel(cyc, priv->membase + UNIPHIER_FI2C_CYC); - writel(cyc / 2, priv->membase + UNIPHIER_FI2C_LCTL); + /* + * Standard-mode: tLOW = 4.7 us, tHIGH = 4.0 us, tBUF = 4.7 us + * Fast-mode: tLOW = 1.3 us, tHIGH = 0.6 us, tBUF = 1.3 us + * "tLow/tHIGH = 5/4" meets both. + */ + writel(cyc * 5 / 9, priv->membase + UNIPHIER_FI2C_LCTL); + /* + * Standard-mode: tHD;STA = 4.0 us, tSU;STA = 4.7 us, tSU;STO = 4.0 us + * Fast-mode: tHD;STA = 0.6 us, tSU;STA = 0.6 us, tSU;STO = 0.6 us + */ writel(cyc / 2, priv->membase + UNIPHIER_FI2C_SSUT); + /* + * Standard-mode: tSU;DAT = 250 ns + * Fast-mode: tSU;DAT = 100 ns + */ writel(cyc / 16, priv->membase + UNIPHIER_FI2C_DSUT); uniphier_fi2c_prepare_operation(priv); -- 2.19.1