From mboxrd@z Thu Jan 1 00:00:00 1970 From: Manuel Jander Subject: Serial loop back virtual device Date: Thu, 2 Jul 2009 22:08:52 +0200 Message-ID: <21ed1c370907021308g18fb0ab5r895ee8871244a341@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-fx0-f218.google.com ([209.85.220.218]:56604 "EHLO mail-fx0-f218.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757377AbZGBUIv (ORCPT ); Thu, 2 Jul 2009 16:08:51 -0400 Received: by fxm18 with SMTP id 18so1742520fxm.37 for ; Thu, 02 Jul 2009 13:08:53 -0700 (PDT) Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: linux-serial@vger.kernel.org Hi there, hopefuly this message is going to the right people. I wrote a small virtual serial loop back driver and I have some questions in regard to that. First, the driver basically creates a set of serial port device pairs (/dev/ttySL0, /dev/ttySL1, etc) and if some programs talks to one of this ports, the counterpart port will receive all data and vice versa. This is usful for writing a simulator of a hardware device which has a serial port, without having to connect to real serial ports together with a null modem cable or something like that. I'm using to develop a simulator of Webasto W-Bus (ODB-II) car heating device. The driver can optionally do line echo, required for K-Line emulation. Now the questions: - Did I really need to write a driver like this or are there any trivial tricks to accomplish this somehow else ? Note, that the software to talk to my simulator is a propietary windows executable (using wine), thus I can not modify it. And my computer has only one single serial port (and I would need to buy a second ODB-II hardware adapter anyway, software is way much cheaper). - Is this useful to anyone ? I think it is :) and it would be kind of stupid if anyone requiring this would have to either use 2 hardware ports or write another driver like this. But maybe I'm wrong, I dont know. - Is this driver worth to be part of the Linux mainline tree ? Probably some adjustment would be required... source code is available here: http://micro.homelinux.net/~mjander/serial_loop.zip It did built on 2.6.28, hopefuly it also does on the current vanilla tree. Best Regards, Manuel