Re: Sensor with 7 bit address above 0x77

[Wolfram Sang <wsa@the-dreams.de>]

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> The way it is written in the spec (1111 0XX) probably caused people to
> confuse it for 0xF0-0xF3 which I found in some messages on the mailing
> list.

Yes, it always causes confusion if the R/W bit is part of the address or
not.

> But that still leaves the question of where the 0xA... in the kernel docs
> came from.

less Documentation/i2c/ten-bit-addresses

> Section 3.1.12 ends with some musings about the assignment of addresses in
> "local systems". More specifically, it ends with the sentence "If it is known
> that the reserved address is never going to be used for its intended purpose,
> a reserved address can be used for a slave address."
> 
> I _do_ know that there are no 10 bit addressed slaves in my application, so
> the spec allows me to use at those 4 slave address. Apparently it is not my
> device that is broken.

For your specific case, I agree. For the generic case, I don't. Maybe
the word "broken" is too much, though, how about calling it "risky"?
That being said, as I mentioned before, I think patches adding support
for using "risky" addresses in i2c-tools are acceptable, so no
show-stopper here.

Can you share which device uses the address 0x78? I'd like to add it to
my list of "interesting I2C devices".


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