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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CEF31C001E0 for ; Mon, 23 Oct 2023 11:43:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234402AbjJWLnq (ORCPT ); Mon, 23 Oct 2023 07:43:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46530 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234407AbjJWLn3 (ORCPT ); Mon, 23 Oct 2023 07:43:29 -0400 Received: from out30-101.freemail.mail.aliyun.com (out30-101.freemail.mail.aliyun.com [115.124.30.101]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9E30310F7; Mon, 23 Oct 2023 04:43:25 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R411e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045192;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0VukmBk1_1698061400; Received: from 30.97.48.63(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0VukmBk1_1698061400) by smtp.aliyun-inc.com; Mon, 23 Oct 2023 19:43:21 +0800 Message-ID: <33b514a0-2ea3-35d6-944c-03ce4c61a6c4@linux.alibaba.com> Date: Mon, 23 Oct 2023 19:43:36 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 Subject: Re: [PATCH V2 7/7] i2c: sprd: Add I2C_NACK_EN and I2C_TRANS_EN control bits To: Huangzheng Lai , Andi Shyti Cc: Orson Zhai , Chunyan Zhang , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, huangzheng lai , Xiongpeng Wu References: <20231023081158.10654-1-Huangzheng.Lai@unisoc.com> <20231023081158.10654-8-Huangzheng.Lai@unisoc.com> From: Baolin Wang In-Reply-To: <20231023081158.10654-8-Huangzheng.Lai@unisoc.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/23/2023 4:11 PM, Huangzheng Lai wrote: > The new I2C IP version on the UNISOC platform has added I2C_NACK_EN and > I2C_TRANS_EN control bits. To ensure that the I2C controller can initiate > transmission smoothly, these two bits need to be configured. What is the side impact for old hardwares that does not support these 2 bits? > Signed-off-by: Huangzheng Lai > --- > drivers/i2c/busses/i2c-sprd.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/i2c/busses/i2c-sprd.c b/drivers/i2c/busses/i2c-sprd.c > index dbdac89ad482..431c0db84d22 100644 > --- a/drivers/i2c/busses/i2c-sprd.c > +++ b/drivers/i2c/busses/i2c-sprd.c > @@ -33,6 +33,8 @@ > #define ADDR_RST 0x2c > > /* I2C_CTL */ > +#define I2C_NACK_EN BIT(22) > +#define I2C_TRANS_EN BIT(21) > #define STP_EN BIT(20) > #define FIFO_AF_LVL_MASK GENMASK(19, 16) > #define FIFO_AF_LVL 16 > @@ -366,7 +368,7 @@ static void sprd_i2c_enable(struct sprd_i2c *i2c_dev) > sprd_i2c_clear_irq(i2c_dev); > > tmp = readl(i2c_dev->base + I2C_CTL); > - writel(tmp | I2C_EN | I2C_INT_EN, i2c_dev->base + I2C_CTL); > + writel(tmp | I2C_EN | I2C_INT_EN | I2C_NACK_EN | I2C_TRANS_EN, i2c_dev->base + I2C_CTL); > } > > static int sprd_i2c_master_xfer(struct i2c_adapter *i2c_adap,