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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 1DA97C10DCE for ; Wed, 18 Mar 2020 14:27:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E835E20772 for ; Wed, 18 Mar 2020 14:27:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726893AbgCRO1B (ORCPT ); Wed, 18 Mar 2020 10:27:01 -0400 Received: from gloria.sntech.de ([185.11.138.130]:37366 "EHLO gloria.sntech.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726973AbgCRO1B (ORCPT ); Wed, 18 Mar 2020 10:27:01 -0400 Received: from [94.134.91.63] (helo=phil.fritz.box) by gloria.sntech.de with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89) (envelope-from ) id 1jEZep-0004YX-BN; Wed, 18 Mar 2020 15:26:55 +0100 From: Heiko Stuebner To: gregkh@linuxfoundation.org Cc: jslaby@suse.com, andriy.shevchenko@linux.intel.com, matwey.kornilov@gmail.com, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, heiko@sntech.de, Heiko Stuebner Subject: [PATCH 5/7] serial: 8250: handle DTR in rs485 emulation Date: Wed, 18 Mar 2020 15:26:38 +0100 Message-Id: <20200318142640.982763-6-heiko@sntech.de> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200318142640.982763-1-heiko@sntech.de> References: <20200318142640.982763-1-heiko@sntech.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org From: Heiko Stuebner While in a lot of cases only RTS is needed as DE signal, sometimes the RE signals is to be controlled separately, as DTR pin. So add necessary control functions for it. Signed-off-by: Heiko Stuebner --- drivers/tty/serial/8250/8250_port.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 3d1d8490bc42..f8e5c096ed51 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -572,6 +572,10 @@ static inline void serial8250_em485_rts_after_send(struct uart_8250_port *p) mcr &= ~UART_MCR_RTS; p->port.mctrl &= ~TIOCM_RTS; } + + mcr |= UART_MCR_DTR; + p->port.mctrl |= TIOCM_DTR; + serial8250_out_MCR(p, mcr); } @@ -1558,6 +1562,13 @@ static inline void start_tx_rs485(struct uart_port *port) em485->active_timer = NULL; mcr = serial8250_in_MCR(up); + + /* in rx_during_tx mode keep DTR active, to receive data */ + if (up->port.rs485.flags & SER_RS485_RX_DURING_TX) + mcr |= UART_MCR_DTR; + else + mcr &= ~UART_MCR_DTR; + if (!!(up->port.rs485.flags & SER_RS485_RTS_ON_SEND) != !!(mcr & UART_MCR_RTS)) { if (up->port.rs485.flags & SER_RS485_RTS_ON_SEND) @@ -1572,6 +1583,8 @@ static inline void start_tx_rs485(struct uart_port *port) up->port.rs485.delay_rts_before_send); return; } + } else { + serial8250_out_MCR(up, mcr); } __start_tx(port); -- 2.24.1