Quoting Bernd Walter <[EMAIL PROTECTED]> (from Wed, 17 Oct 2007
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
regarding embedded devices: there you craft your kernel by hand anyway
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
used) where this is the case? If not, do you think that with the
vendor mentality of saving every fraction of a cent it is likely, that
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
i386/amd64?
On Mon, Oct 15, 2007 at 08:15:07AM +0200, Alexander Leidinger wrote:
Quoting Poul-Henning Kamp <[EMAIL PROTECTED]> (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=0xd0
[...]
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
can help further if Constantine has questions regarding it and Sam has
no time to answer?
Bye,
Alexander.
--
http://www.Leidinger.net Alexander @ Leidinger.net: PGP ID = B0063FE7
http://www.FreeBSD.org netchild @ FreeBSD.org : PGP ID = 72077137
Any circuit design must contain at least one part which is obsolete, two parts
which are unobtainable, and three parts which are still under development.
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