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=-17.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 D2E50C28E89 for ; Tue, 2 Mar 2021 20:09:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A9AB564F25 for ; Tue, 2 Mar 2021 20:09:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1582012AbhCBUBy (ORCPT ); Tue, 2 Mar 2021 15:01:54 -0500 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:41702 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1379949AbhCBKWF (ORCPT ); Tue, 2 Mar 2021 05:22:05 -0500 Received: from pps.filterd (m0046661.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 122AHmce015298; Tue, 2 Mar 2021 11:20:10 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=selector1; bh=AHNRA07W/8XeOi1fcP+UwN+hE9l5HeWlAvjNP7Od2XQ=; b=K44Nf8dxpJTK46y0qHK1yIq2djKmoAPatyObmNxYQPiIHtUDRntpEEGxwmjemolYJOln TwbbG4a5qd9k9WdP1v6bqkilm8txSV4YWh2FMjdeyLo0GsgGF4KSKVWDkXaI3jzl75y+ x84hXPiJBBmoociIaR/6Cv4F1QVmeyaMRocSFDuzJ7i0ljHCHU0VoSRtZyMIprqvkHEP Gsq7KBRJwOD0nOLLa0NZI6Q1MTY1hjGfS1xcN/CMXD4DTnGW0mdvpZNxSbwWD3l50Yfj r6gBbq9PjvdEQl60wr1Shi3WdX2iPAmaoNBZQ8kSJnLQpKWrnkDlvCnxz13uddjcsCbQ 8g== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 36yf9q1dun-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 02 Mar 2021 11:20:10 +0100 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 93F86100034; Tue, 2 Mar 2021 11:20:09 +0100 (CET) Received: from Webmail-eu.st.com (sfhdag2node3.st.com [10.75.127.6]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 717022C38D2; Tue, 2 Mar 2021 11:20:09 +0100 (CET) Received: from [10.211.13.170] (10.75.127.50) by SFHDAG2NODE3.st.com (10.75.127.6) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 2 Mar 2021 11:20:08 +0100 Subject: Re: [PATCH v2 1/2] tty/serial: Add rx-tx-swap OF option to stm32-usart To: Martin DEVERA , CC: , Alexandre Torgue , Greg Kroah-Hartman , Rob Herring , , Maxime Coquelin , , Jiri Slaby , , Le Ray References: <20210227164157.30971-1-devik@eaxlabs.cz> <439a0d7a-cc0e-764b-7ed8-668b5a85f4a7@foss.st.com> From: Fabrice Gasnier Message-ID: <019b62e9-ec9b-d366-ee77-59c980d66a07@foss.st.com> Date: Tue, 2 Mar 2021 11:20:07 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [10.75.127.50] X-ClientProxiedBy: SFHDAG3NODE2.st.com (10.75.127.8) To SFHDAG2NODE3.st.com (10.75.127.6) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369,18.0.761 definitions=2021-03-02_03:2021-03-01,2021-03-02 signatures=0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 3/1/21 11:40 PM, Martin DEVERA wrote: > On 3/1/21 11:28 AM, Fabrice Gasnier wrote: >> On 2/27/21 5:41 PM, Martin Devera wrote: >>> STM32 F7/H7 usarts supports RX & TX pin swapping. >>> Add option to turn it on. >>> Tested on STM32MP157. >>> >>> Signed-off-by: Martin Devera >>> --- >>>   drivers/tty/serial/stm32-usart.c | 3 ++- >>>   drivers/tty/serial/stm32-usart.h | 1 + >>>   2 files changed, 3 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/tty/serial/stm32-usart.c >>> b/drivers/tty/serial/stm32-usart.c >>> index b3675cf25a69..3650c8798061 100644 >>> --- a/drivers/tty/serial/stm32-usart.c >>> +++ b/drivers/tty/serial/stm32-usart.c >>> @@ -758,7 +758,7 @@ static void stm32_usart_set_termios(struct >>> uart_port *port, >>>       cr1 = USART_CR1_TE | USART_CR1_RE; >>>       if (stm32_port->fifoen) >>>           cr1 |= USART_CR1_FIFOEN; >>> -    cr2 = 0; >>> +    cr2 = stm32_port->swap ? USART_CR2_SWAP : 0; >> Hi Martin, >> >> Same could be done in the startup routine, that enables the port for >> reception (as described in Documentation/driver-api/serial/driver.rst) > Hello Fabrice, > > I already incorporated all your comments but I'm struggling with the one > above. > The code must be in stm32_usart_set_termios too, because CR2 is modified. Hi Martin, Yes, sure, > What is the reason to have it in startup() ? RX is enabled at both places. So the swap setting should be there too. > Is it because USART can be started without calling set_termios at all ? Yes, that's what the driver API expects: "startup(port)" ... "Enable the port for reception." Best Regards, Fabrice > Like > to reuse bootloader's last settings ? > > Thanks, Martin >