From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Stein Subject: Re: [PATCH] Documentation about RS485 serial communications Date: Wed, 20 Oct 2010 10:00:14 +0200 Message-ID: <201010201000.14905.alexander.stein@systec-electronic.com> References: <20100408111310.524f7354@lxorguk.ukuu.org.uk> <201010191727.53314.alexander.stein@systec-electronic.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from webbox687.server-home.net ([195.149.74.151]:52332 "EHLO webbox687.server-home.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751008Ab0JTIAS (ORCPT ); Wed, 20 Oct 2010 04:00:18 -0400 In-Reply-To: Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: linux-arm-kernel@lists.infradead.org Cc: Grant Edwards , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org On Tuesday 19 October 2010, 19:22:32 Grant Edwards wrote: > Yes, the AT91 UARTs do have a built-in half-duplex mode that will > automatically control line direction by toggling RTS. > > That can used to control external half-duplex hardware like an RS485 > transceiver or any RS232-connected half-duplex device like some > modems. > > Though the Atmel docs refer to it as "RS485 mode" there is no RS485 > transceiver in the AT91 parts (AFAIK), and "RS485 mode" isn't specific > to RS485 - it can be used with any external half-duplex hardware. Out of curiosity, how can I add RS485 (or whatever) support for other serial devices like e.g. i.mx serial? Is there some driver independent interface which only gets filled in board configs like setting some GPIO pins? Alexander