Re: [PATCH 2/3] i2c: slave-eeprom: add eeprom simulator driver

Wolfram Sang
2014-11-26T12:47:35Z

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On Wed, Nov 26, 2014 at 03:25:29PM +0300, Alexander Kochetkov wrote:
>
> 22 нояб. 2014 г., в 21:12, Wolfram Sang <wsa@the-dreams.de> написал(а):
>
> > IMO a repeated start is to ensure that two messages arrive at the slave
> > without interruption from another master. I can't think why a slave
> > should know which type of start that was. In fact, if it does that would
> > raise an eyebrow for me. Do you have an example?
>
> It is used to implement Device ID reading.

Yes and no, I'd say :) Technically, it needs repeated start. But really,
the hardware should handle this (and I know one IP core which has
support for it). One could try to simulate the behaviour in the bus
driver IF a second slave address AND detection of repeated start is
available, but I doubt this combination exists.

Still, all the _slave driver_ needs to handle is an
I2C_SLAVE_EVENT_DEVICE_ID which should return the apropriate value.

That being said, I have never seen querying Device ID in action.

> Not sure, that the feature is really needed for the first release.

I am sure it is not :D

Thanks,

Wolfram

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