Hi Chris,

> How about a range of -4% to +2% ?

I am fine with a range in general, but I don't like +x% because we should never
be faster than requested. Clients may have problems with that.

> Technically, to do it right, to calculate the ACTUAL I2C baud rate, you 
> have to take into effect the load resistance and capacitance of the 
> lines in order to factor in the rise and fall times correctly. Of course 

We have those generic bindings upstream:

- i2c-scl-falling-time-ns
        Number of nanoseconds the SCL signal takes to fall; t(f) in the I2C
        specification.

- i2c-scl-internal-delay-ns
        Number of nanoseconds the IP core additionally needs to setup SCL.

- i2c-scl-rising-time-ns
        Number of nanoseconds the SCL signal takes to rise; t(r) in the I2C
        specification.

- i2c-sda-falling-time-ns
        Number of nanoseconds the SDA signal takes to fall; t(f) in the I2C
        specification.

So far, that was all that is needed, however...

> Just live with the fact that the speed might be off by 4%.

... as I said before, I won't force it on you for the frequencies you want to
support.

Regards,

   Wolfram

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