From owner-freebsd-hackers Sun Jun 14 11:23:17 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id LAA08329 for freebsd-hackers-outgoing; Sun, 14 Jun 1998 11:23:17 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from hda.hda.com (hda-bicnet.bicnet.net [208.220.66.37]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id LAA08292 for ; Sun, 14 Jun 1998 11:22:56 -0700 (PDT) (envelope-from dufault@hda.hda.com) Received: (from dufault@localhost) by hda.hda.com (8.8.5/8.8.5) id NAA07458; Sun, 14 Jun 1998 13:57:49 -0400 (EDT) From: Peter Dufault Message-Id: <199806141757.NAA07458@hda.hda.com> Subject: Re: I2C bus In-Reply-To: <19980609234406.41618@breizh.prism.uvsq.fr> from Nicolas Souchu at "Jun 9, 98 11:44:06 pm" To: Nicolas.Souchu@prism.uvsq.fr (Nicolas Souchu) Date: Sun, 14 Jun 1998 13:57:48 -0400 (EDT) Cc: freebsd-hackers@FreeBSD.ORG, mbouget@club-internet.fr X-Mailer: ELM [version 2.4ME+ PL25 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > We're about to write Philips semiconductor support for the I2C bus. I put my latest code up on incoming where the incoming elves will move it someplace else and I guess tell us. Look for "i2c.tgz" dated June 14. This code will be the basis for a FreeBSD driver for boards/systems based on the Philips controller chip that I'll be putting together real soon, well, as soon as that problem bubbles to the top of my priority list, hopefully this month. If someone is interested in working toward a bit-banging (i.e., line printer port etc) implementation then they should look at the i2cslave code in that tar ball and consider what it would take to make a non-blocking state driven master similar to the non-blocking state driven slave that it now implements. I'm not going to have a lot of time to work on this, so I'll be changing this for my needs. Specifically, I plan on changing the current i2c.c Philips code to a reentrant interrupt driven driver with the slave address encoded in the device minor number. I'll keep in the back of my mind the idea that someone may want to splice in the bit banging code, so I'll modify the current compile time selection to be member-function table driven. This is not the greatest code since it has always been developed specifically to meet my needs. However, it is wrung out, has run in several environments over the last 5 or 6 years, and is solid from the point of view of timing. Enjoy - Peter -- Peter Dufault (dufault@hda.com) Realtime development, Machine control, HD Associates, Inc. Safety critical systems, Agency approval To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message