RE: [PATCH v26 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs and transfer-mode properties

> Subject: Re: [PATCH v26 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs
> and transfer-mode properties
> 
> Hi Ryan,
> 
> > Your understanding is correct; the byte and buffer mode is mostly the
> > same. And also mode should be decided before xfer, due to the
> > controller/target both use the same xfer mode, not decide by transfer
> > time. The original my submit is only buffer mode and dma mode, and use
> > only one Boolean property, aspeed,i2c-dma-enabled, but someone suggest
> > add byte mode select, so I start to add at v17. I can drop the byte
> > mode, if this is confused.
> >
> > byte mode request:
> > https://lore.kernel.org/all/010e55e9-d58b-444c-ab57-
> > [email protected]/
> 
> OK, that sounds like more driver configuration than hardware description
> though.
> 
> > > Ryan: I think this gives us a much cleaner approach to the binding.
> > Thanks the feedback, do you mean, just one boolean property for mode
> > selection, Am I right?
> 
> It's less about "mode selection" (which is a driver implementation
> consideration) and more about "hardware capability", which I think the
> boolean property better represents.
> 
> The driver implementation could do whatever it likes with the information
> about whether a DMA channel is allocated (and select a suitable mode
> depending on that, and/or other runtime data).
> 
> This property only seems to be applicable to 2600 though, as there is no need
> for it on 2700, if all controllers are DMA-capable.
>  
Thanks the input, I will modify support boolean property aspeed,i2c-dma-enabled,
Yes, ast2700 all controller support DMA.