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[Bug 1001397] I2C driver for Kinetic microcontrollers


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--- Comment #15 from Ilija Kocho <ilijak@siva.com.mk> 2012-02-08 09:54:55 GMT ---
(In reply to comment #14)
> (In reply to comment #13)
> >     -Can I2C clock be defined on device basis like at SPI?
> 
> Yes, I think it should be possible to change the bus speed when the device
> takes over the mastership of the bus, I shall look into that.
> 
> > Next is general, could it be possible to provide user with option to set I2C
> > speed (clock) rather than prescaler value?
> 
> I can't see any way to translate the SCL/SDA values that are need to calculate
> the i2c speed into the MUL + ICR values that need to go into the frequency
> divider register; the RM just provides a one big LUT for this.

Yeah, it's kind of reverse calculation. I had similar problem with SPI and I
use a brute force algorithm. But some SPI devices (example MMC) want to set
speed on their own so having this calculation is necessary anyway. In I2C world
it may be not the case (frankly, I have no insight) so it could be just "nice"
but not mandatory.

Ilija

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