[coreboot] New interface for I2C in coreboot

[Peter Stuge]

Julius Werner wrote:
> > We maybe can expand it to have informations like time-out or
> > retry count for a given segment.
> 
> One word of caution I'd like to add here is that making this API more
> complex/powerful requires significant effort, now and in the future.

Not if the architecture is any good.

> We already have 4 I2C driver implementations in coreboot, and 4 more
> are going to be upstreamed soon from the Chromium tree. As we scale up
> to we'll probably add at least one new driver per SoC vendor, maybe
> even per SoC. Adding complex functionality like retries to the API
> will require us to account for it over an over again in every single
> implementation.

No - that doesn't make any sense. Probably there will be a fair bit
of code that can be shared among controllers. There aren't that many
ways to implement I²C.


> I think the question is really what we would gain from this.

I think it's less about performance and more about an accurate and
clean model being available to mainboard code when needed.


//Peter