Date: Tue, 13 Oct 1998 23:52:46 +0000 From: Nicolas Souchu <Nicolas.Souchu@prism.uvsq.fr> To: Julian Elischer <julian@whistle.com> Cc: FreeBSD Hackers <freebsd-hackers@FreeBSD.ORG>, -current <freebsd-current@FreeBSD.ORG>, Luigi Rizzo <luigi@labinfo.iet.unipi.it>, Roger Hardiman <roger@cs.strath.ac.uk>, Mike Smith <mike@smith.net.au>, Marc Bouget <mbouget@club-internet.fr> Subject: Re: bktr over new I2C framework, ready Message-ID: <19981013235246.02264@breizh.prism.uvsq.fr> In-Reply-To: <Pine.BSF.3.95.981012154124.2872E-100000@current1.whistle.com>; from Julian Elischer on Mon, Oct 12, 1998 at 03:42:26PM -0700 References: <19981012195634.06516@breizh.prism.uvsq.fr> <Pine.BSF.3.95.981012154124.2872E-100000@current1.whistle.com>
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On Mon, Oct 12, 1998 at 03:42:26PM -0700, Julian Elischer wrote: >yes but what IS it? > >I have an I2C device attached to some programmable pins >and I understand the protocol, >but 'bktr' means nothing to me.. What is it? > >julian > >On Mon, 12 Oct 1998, Nicolas Souchu wrote: > >> Hi there, >> >> bktr over the new I2C framework is now ready. Although, no man page is >> available :( This is my next priority. >> >> But it works. Ready to test it? >> >> -- Sorry, I'm not generous in details :) I2C is a very powerful and low-cost serial bus specified by Philips for multimedia purposes. A master chip on the bus controls slave chips (memories, voltage sensors, termometers, EEPROMs, batteries) with any byte oriented protocol. The System Management Bus found on laptops to control battery is an example of such protocols. Asus motherboards have monitoring capabilities (controling temperature, ventilators rotation speed) with rely on an I2C bus with the SMB protocol. I2C may be controled by hardware (writing to regiters to send bytes on the bus) or by software (twiggling line directly) bktr is the driver of the Brooktree848 video chipset found for example on TV video cards. The bt848 chip has I2C capabilities on-chip to control tuners, sound processors... the bt848 has both software and hardware capabilities. I2C busses are growing like mushrooms. Since the 430TX, Intel incorporates I2C to its chips. The Apollo, Aladdin chipsets may act as master over an I2C bus too. The idea of the FreeBSD I2C system is to offer a general purpose framework in order to avoid rewritting i2c common functions in every driver and propose for example generic i/o for any card that has an external I2C connector. bktr now relies on the new I2C framework. Other drivers that use I2C protocol should too. I'm about to write manpages and gather some urls on a web page. Nicolas. -- Nicolas.Souchu@prism.uvsq.fr FreeBSD - Turning PCs into workstations - http://www.FreeBSD.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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