From patchwork Tue Aug 4 11:44:52 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?RWRkaWUgSHVhbmcgKOm7g+aZuuWCkSk=?= X-Patchwork-Id: 6936701 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id EEC4FC05AC for ; Tue, 4 Aug 2015 11:48:59 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1403220443 for ; Tue, 4 Aug 2015 11:48:59 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2511320450 for ; Tue, 4 Aug 2015 11:48:58 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZMafJ-0005Nc-3A; Tue, 04 Aug 2015 11:45:53 +0000 Received: from [210.61.82.184] (helo=mailgw02.mediatek.com) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZMafE-0005IA-BQ; Tue, 04 Aug 2015 11:45:49 +0000 X-Listener-Flag: 11101 Received: from mtkhts07.mediatek.inc [(172.21.101.69)] by mailgw02.mediatek.com (envelope-from ) (mhqrelay.mediatek.com ESMTP with TLS) with ESMTP id 1852197158; Tue, 04 Aug 2015 19:45:07 +0800 Received: from mtkslt208.mediatek.inc (10.21.15.95) by mtkhts07.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 14.3.181.6; Tue, 4 Aug 2015 19:45:06 +0800 From: Eddie Huang To: Wolfram Sang Subject: [PATCH 1/2] i2c: mediatek: Reset DMA engine in hardware init function Date: Tue, 4 Aug 2015 19:44:52 +0800 Message-ID: <1438688693-60275-2-git-send-email-eddie.huang@mediatek.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1438688693-60275-1-git-send-email-eddie.huang@mediatek.com> References: <1438688693-60275-1-git-send-email-eddie.huang@mediatek.com> MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150804_044548_684511_BC9873D5 X-CRM114-Status: GOOD ( 16.17 ) X-Spam-Score: -1.1 (-) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Xudong Chen , srv_heupstream@mediatek.com, Sascha Hauer , Liguo Zhang , linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-i2c@vger.kernel.org, Matthias Brugger , Eddie Huang , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Reset DMA in hardware init function to avoid unknown hardware state before do any I2C operation. Signed-off-by: Liguo Zhang Signed-off-by: Eddie Huang --- drivers/i2c/busses/i2c-mt65xx.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c index 9920eef..055159d 100644 --- a/drivers/i2c/busses/i2c-mt65xx.c +++ b/drivers/i2c/busses/i2c-mt65xx.c @@ -1,6 +1,8 @@ /* * Copyright (c) 2014 MediaTek Inc. - * Author: Xudong Chen + * Author: + * Xudong Chen + * Liguo Zhang * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as @@ -59,6 +61,7 @@ #define I2C_DMA_START_EN 0x0001 #define I2C_DMA_INT_FLAG_NONE 0x0000 #define I2C_DMA_CLR_FLAG 0x0000 +#define I2C_DMA_HARD_RST 0x0002 #define I2C_DEFAULT_SPEED 100000 /* hz */ #define MAX_FS_MODE_SPEED 400000 @@ -81,6 +84,7 @@ enum DMA_REGS_OFFSET { OFFSET_INT_FLAG = 0x0, OFFSET_INT_EN = 0x04, OFFSET_EN = 0x08, + OFFSET_RST = 0x0c, OFFSET_CON = 0x18, OFFSET_TX_MEM_ADDR = 0x1c, OFFSET_RX_MEM_ADDR = 0x20, @@ -262,6 +266,10 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c) I2C_CONTROL_CLK_EXT_EN | I2C_CONTROL_DMA_EN; writew(control_reg, i2c->base + OFFSET_CONTROL); writew(I2C_DELAY_LEN, i2c->base + OFFSET_DELAY_LEN); + + writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST); + udelay(50); + writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST); } /*