From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: atmel_serial: fix RTS high after initialization in RS485 mode Date: Mon, 25 Oct 2010 15:54:10 -0700 Message-ID: <20101025155410.f960fcd5.akpm@linux-foundation.org> References: <4CC40EFD.8070000@evidence.eu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:32865 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752049Ab0JYWyn (ORCPT ); Mon, 25 Oct 2010 18:54:43 -0400 In-Reply-To: <4CC40EFD.8070000@evidence.eu.com> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Claudio Scordino Cc: Nicolas Ferre , Arkadiusz =?UTF-8?Q?Buba?= =?UTF-8?Q?=C5=82a?= , linux@maxim.org.za, linux-arm-kernel , Linux Kernel , "linux-serial@vger.kernel.org" , Greg KH On Sun, 24 Oct 2010 12:48:29 +0200 Claudio Scordino wrote: > Hi Nicolas, > > when working in RS485 mode, the atmel_serial driver keeps RTS > high after the initialization of the serial port. It goes low only after > the first character has been sent. > > This patch fixes this behavior. It has been already tested by Arkadiusz (CC:-ed). > > Best regards, > > Claudio > > > atmel_serial: RTS line low after initialization of the serial port > > Signed-off-by: Claudio Scordino > Signed-off-by: Arkadiusz Bubala > --- > drivers/serial/atmel_serial.c | 9 +++++++++ > 1 files changed, 9 insertions(+), 0 deletions(-) > > diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c > index 3892666..85aa66f 100644 > --- a/drivers/serial/atmel_serial.c > +++ b/drivers/serial/atmel_serial.c > @@ -1732,6 +1732,15 @@ static int __devinit atmel_serial_probe(struct platform_device *pdev) > device_init_wakeup(&pdev->dev, 1); > platform_set_drvdata(pdev, port); > > + if (port->rs485.flags & SER_RS485_ENABLED) { > + unsigned int control = 0; > + unsigned int mode = 0; > + control |= ATMEL_US_RTSEN; > + mode |= ATMEL_US_USMODE_NORMAL; > + UART_PUT_MR(&port->uart, mode); > + UART_PUT_CR(&port->uart, control); > + } > + > return 0; > That was a lot of code! How about just this? if (port->rs485.flags & SER_RS485_ENABLED) { UART_PUT_MR(&port->uart, ATMEL_US_USMODE_NORMAL); UART_PUT_CR(&port->uart, ATMEL_US_RTSEN); }