From patchwork Thu Jun 1 16:31:12 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hugo Villeneuve X-Patchwork-Id: 102093 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:994d:0:b0:3d9:f83d:47d9 with SMTP id k13csp472852vqr; Thu, 1 Jun 2023 09:53:55 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ5s50HLUoEVFbNVbw6t6rTdxtD1fLvGfDrN1RDN5usi9thzp5HbpRNtdWK/BeDAp5OXHJzI X-Received: by 2002:a05:6a00:842:b0:64d:3227:b806 with SMTP id q2-20020a056a00084200b0064d3227b806mr8597162pfk.33.1685638434856; Thu, 01 Jun 2023 09:53:54 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1685638434; cv=none; d=google.com; s=arc-20160816; b=ltrJeg0YdRWYj2TmiAZNFssKRz+Q7d4bud9LkK6jTqdW/bZIYx1R/DsomS9MNhlLt6 Flz5f3vmQiVji6/foOIJkt8D8YQFgoUiX3uOsj642KEJYvQsiJFmoS8Z2FvwQ2WSmiTb XhOInmLE4qTlGynPAxbOdsV8IDqg/JhJsMXqAG9WouRSw5ZlSd+d199uuoF4DR8rH0Tz 987fc3JfPdrwFMu69c69QD1ephP+FFkcOUoy9pmg36LgYxeoBVkMGr/ceNBaso2cw7M2 Qw1DfpwOdh1YHPKjgCSNaVXSFHft3Df+2aXrF9i7ooyIrcj+JTgEEmkYo4jYgouANhHo 8ipg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:subject:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:cc:to:from:dkim-signature; bh=fISA+M83zRFEgKAdJUAq2HgGHBk9L99uymCON8uLsVo=; b=Ac1H2xjK5PzXFijVttW8QDPk0X/I9jf88XGEUImL4FGY7OR6R0rRlpiyjbPyj8DLuS kCWUO+NLmd9hP+wkWX+nYvYD0+Hna1g7WRK4PdG6zUqiEazJZsn/jnButMkBkpteIfFK Jzh6YICkS924UFQvstMRpU3vdrNEg6M3qEfYfrnA9lG8WOLJIyw/fAdk10j8HYcX2Om7 XdJkWhFIB6ph9go94ajP/FpvXp3MF7gIxrPKusBGIhzbIGSuSCm4Qv9Fa6m1aqdMdd6b /MqRQoVNY67VjYr3snRIMVr0psK+WkymxdBkKRGZ4D1lqcez0COyF1BkjGmIw64h1QOl f2OA== ARC-Authentication-Results: i=1; mx.google.com; dkim=fail header.i=@hugovil.com header.s=x header.b=NcOSLRdg; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id h13-20020a056a00000d00b0064f78c32b89si5744554pfk.95.2023.06.01.09.53.42; Thu, 01 Jun 2023 09:53:54 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=fail header.i=@hugovil.com header.s=x header.b=NcOSLRdg; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231987AbjFAQtO (ORCPT + 99 others); Thu, 1 Jun 2023 12:49:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60682 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231698AbjFAQtI (ORCPT ); Thu, 1 Jun 2023 12:49:08 -0400 Received: from mail.hugovil.com (mail.hugovil.com [162.243.120.170]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 131CD194; Thu, 1 Jun 2023 09:49:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=hugovil.com ; s=x; h=Subject:Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-Id:Date:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=fISA+M83zRFEgKAdJUAq2HgGHBk9L99uymCON8uLsVo=; b=NcOSLRdgECoggvVq0+v0TKSEji TBzrAhx9FH3+c6VakFHL/u0DxXl09zr+v6SvL11q0q46QwIiAUrwfUHkNzw2bcKTpO9sUBfJNooFW W/Eb4rWAJJE1rmtbR4Pv41/3iBwcCWG5J21aiMfptm4JkR2nt1jgfKEICnoT8QkAk0hA=; Received: from modemcable168.174-80-70.mc.videotron.ca ([70.80.174.168]:53588 helo=pettiford.lan) by mail.hugovil.com with esmtpa (Exim 4.92) (envelope-from ) id 1q4lCz-0003BU-OO; Thu, 01 Jun 2023 12:31:30 -0400 From: Hugo Villeneuve To: gregkh@linuxfoundation.org, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, jirislaby@kernel.org, jringle@gridpoint.com, l.perczak@camlintechnologies.com, tomasz.mon@camlingroup.com Cc: linux-serial@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, hugo@hugovil.com, linux-gpio@vger.kernel.org, Hugo Villeneuve , Lech Perczak Date: Thu, 1 Jun 2023 12:31:12 -0400 Message-Id: <20230601163113.2785657-9-hugo@hugovil.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230601163113.2785657-1-hugo@hugovil.com> References: <20230601163113.2785657-1-hugo@hugovil.com> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 70.80.174.168 X-SA-Exim-Mail-From: hugo@hugovil.com X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Spam-Level: X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_PASS,SPF_PASS, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 Subject: [PATCH v5 8/9] serial: sc16is7xx: add post reset delay X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on mail.hugovil.com) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1767520007852647713?= X-GMAIL-MSGID: =?utf-8?q?1767520007852647713?= From: Hugo Villeneuve Make sure we wait at least 3us before initiating communication with the device after reset. Signed-off-by: Hugo Villeneuve Reviewed-by: Lech Perczak Tested-by: Lech Perczak --- drivers/tty/serial/sc16is7xx.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 388c1d490853..9b2d58023c55 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -1521,6 +1521,12 @@ static int sc16is7xx_probe(struct device *dev, regmap_write(s->regmap, SC16IS7XX_IOCONTROL_REG << SC16IS7XX_REG_SHIFT, SC16IS7XX_IOCONTROL_SRESET_BIT); + /* + * After reset, the host must wait at least 3us before initializing a + * communication with the device. + */ + usleep_range(5, 10); + for (i = 0; i < devtype->nr_uart; ++i) { s->p[i].line = i; /* Initialize port data */