From owner-freebsd-hackers@FreeBSD.ORG Fri Jan 21 05:52:56 2005 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 120FD16A4CE for ; Fri, 21 Jan 2005 05:52:56 +0000 (GMT) Received: from home.dino.sk (home.dino.sk [213.215.74.194]) by mx1.FreeBSD.org (Postfix) with ESMTP id 95B8D43D46 for ; Fri, 21 Jan 2005 05:52:54 +0000 (GMT) (envelope-from bsd@dino.sk) Received: from [127.0.0.1] ([127.0.0.1]) by home.dino.sk with esmtp; Fri, 21 Jan 2005 06:52:52 +0100 id 0000E89B.41F098B4.000017B0 From: Milan Obuch To: freebsd-hackers@freebsd.org Date: Fri, 21 Jan 2005 06:52:41 +0100 User-Agent: KMail/1.6.2 References: <200501141015.37516.bsd@dino.sk> <200501191000.51574.bsd@dino.sk> <20050120235104.GV19624@funkthat.com> In-Reply-To: <20050120235104.GV19624@funkthat.com> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200501210652.42328.bsd@dino.sk> Subject: Re: Geode integrated peripherals support? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 21 Jan 2005 05:52:56 -0000 On Friday 21 January 2005 00:51, John-Mark Gurney wrote: > Milan Obuch wrote this message on Wed, Jan 19, 2005 at 10:00 +0100: > > [skip] > > Great, could we cooperate? > > Sure, though Joerg Wunsch has been doing work w/ I2C more recently than > me, so you might want to drop him an email. > Is he on this list? I have no other idea how coould I reach him. > > I know there are two modes - bit banging software i2c bus and real > > hardware controller. Which one would be easier to begin with? With geode, > > both are possible. Pins designed for ACCESS.bus (at least the second, > > there are two buses integrated) can be used as GPIO pins. > > The hardware I worked on was bit banging only, so I used that interface > and it was surprisingly easy, since you just define an interface that > will get called by the i2c bus to do the necessary toggling... Of course > this is more cpu intensive since it requires timing and other things > like that.. > Maybe I will try to make bit banged version first. Just when I find all the subtle details necessary to toggle pins... > Take a look at sys/dev/iicbus/iic*_if.m. Those are the two different > programming interfaces. You of course just need to do one of the two... > I did. Actually first I must figure how this all contributes to total picture... I am on my way. I must first know the hardware part, which is not that easy on the first stage, but I am reading through specs, some examples, mostly in assembly. I am doing my homework :) [skip] > > You can take a look at lpbb for a simple example of the bit banging > interface... sys/dev/ppbus/lpbb.c The other controllers also implement > iicbus directly.. You can look at the modules/i2c/contollers/*/Makefile > to see who uses iicbus_if.h to see examples that implement it.. > On the other side - what is sys/dev/pcf directory for? I do not see those files referenced elsewhere... Other than that, device pcf looks like the best candidate to work with. I would like to use integrated controller, naturally. Regards, Milan N. B. No need to send cc: to me, I am subscribed.