Date: Thu, 18 Oct 2007 10:04:42 +0200 From: Alexander Leidinger <netchild@FreeBSD.org> To: ticso@cicely.de, Bernd Walter <ticso@cicely12.cicely.de> Cc: Wilko Bulte <wb@freebie.xs4all.nl>, Poul-Henning Kamp <phk@phk.freebsd.dk>, src-committers@FreeBSD.org, cvs-all@FreeBSD.org, cvs-src@FreeBSD.org Subject: Re: cvs commit: src/etc Makefile sensorsd.conf src/etc/defaults rc.conf src/etc/rc.d Makefile sensorsd src/lib/libc/gen sysctl.3 src/sbin/sysctl sysctl.8 sysctl.c src/share/man/man5 rc.conf.5 src/share/man/man9 Makefile sensor_attach.9 src/sys/conf files ... Message-ID: <20071018100442.a4i5vidp1c0kg8gg@webmail.leidinger.net> In-Reply-To: <20071017155225.GU17048@cicely12.cicely.de> References: <24712.1192384461@critter.freebsd.dk> <20071015081507.yi9t4ot8asg0wcw4@webmail.leidinger.net> <20071014172115.GA24318@freebie.xs4all.nl> <24712.1192384461@critter.freebsd.dk> <20071017155225.GU17048@cicely12.cicely.de>
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Quoting Bernd Walter <ticso@cicely12.cicely.de> (from Wed, 17 Oct 2007 =20 17:52:25 +0200): > For example in the embedded world we can have an i2c system with > commonly used addresses reused for different purpose. Not talking about the specific part at hand (probing i2c), but =20 regarding embedded devices: there you craft your kernel by hand anyway =20 after deciding what you need and what not. > Another example is that there are i2c switches used on alpha systems, > such as the AS4100 - we never supported i2c on alpha, but this doesn't > mean that other systems don't use it as well. Do you know about amd64/i386 systems (where the code you talk about is =20 used) where this is the case? If not, do you think that with the =20 vendor mentality of saving every fraction of a cent it is likely, that =20 they use i2c switches? > Yet another example are the famous atmel eeprom chips used in some IBM > notebooks which died on such an access. That's bad. Can they be affected with by the code in question? > Then we have a bug on some i2c controllers (namely the twi in Atmel > ARM9 chips), which makes it impossible to safely get the ack state > on addressing. Are you talking about embedded stuff, or about stuff which is used on =20 i386/amd64? > On Mon, Oct 15, 2007 at 08:15:07AM +0200, Alexander Leidinger wrote: >> Quoting Poul-Henning Kamp <phk@phk.freebsd.dk> (from Sun, 14 Oct 2007 >> 17:54:21 +0000): >> Could you please explain how you want to integrate devices with >> newbus, which are only accessible via the i2c bus? Feel free to show >> us example code for one of those of our drivers which access the i2c >> bus, which already existed before this commit. > > For example the ds1672 driver (sys/dev/iicbus/ds1672.c) writen by sam: > at91_twi0 > iicbus0 > [...] > ds16720 at addr=3D0xd0 > [...] > The device name is a bit unfortunate - it consists of ds1672 beeing > the driver name and 0 beeing the instance, but this is unrelated. > > The DS1672 is used as an RTC for some ARM boards, but it is written > machine independend. Thanks for this example. Do you know enough about this code that you =20 can help further if Constantine has questions regarding it and Sam has =20 no time to answer? Bye, Alexander. --=20 http://www.Leidinger.net Alexander @ Leidinger.net: PGP ID =3D B0063FE7 http://www.FreeBSD.org netchild @ FreeBSD.org : PGP ID =3D 72077137 Any circuit design must contain at least one part which is obsolete, two par= ts which are unobtainable, and three parts which are still under development.
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