From owner-freebsd-hackers Sun Sep 7 22:09:34 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id WAA06363 for hackers-outgoing; Sun, 7 Sep 1997 22:09:34 -0700 (PDT) Received: from genesis.atrad.adelaide.edu.au (genesis.atrad.adelaide.edu.au [129.127.96.120]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id WAA06354 for ; Sun, 7 Sep 1997 22:09:28 -0700 (PDT) Received: from word.smith.net.au (lot.atrad.adelaide.edu.au [203.20.121.21]) by genesis.atrad.adelaide.edu.au (8.8.5/8.7.3) with ESMTP id OAA24113 for ; Mon, 8 Sep 1997 14:39:18 +0930 (CST) Received: from word.smith.net.au ([127.0.0.1]) by word.smith.net.au (8.8.7/8.8.5) with ESMTP id OAA01269; Mon, 8 Sep 1997 14:05:49 +1000 (EST) Message-Id: <199709080405.OAA01269@word.smith.net.au> X-Mailer: exmh version 2.0zeta 7/24/97 To: =?iso-8859-1?Q?=DEor=F0ur?= Ivarsson cc: hackers@FreeBSD.ORG Subject: Re: How do I write device driver In-reply-to: Your message of "Thu, 04 Sep 1997 15:30:51 GMT." <340ED42B.41C67EA6@est.is> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Mon, 08 Sep 1997 14:05:39 +1000 From: Mike Smith Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > Can any of you help me with writing device driver for two cards i have > here on my desk. > I have all documents and API information for the cards. > > One is AD converter 8input 12bit + 1 DA 12bit > > and the other is digital IO card with 6 8bit ports and timer IO based > on two 8255 and one 8253 > > I heard of something like /dev/IO but I did not find any information > about writing interface to it. You don't have to do much for this; just open /dev/io and use the macros in , specifically the in* and out* family. The first question you should ask is : do you need a device driver? If you don't need to handle DMA or interrupts or have strict timing requirements, user-mode I/O using the /dev/io technique can be very effective. We have a data interface capable of >1MB/sec that we talk to exclusively with this method. mike