Re: [PATCH v2 2/2] dt-binding: spi: Document Renesas R-Car Gen3 RPC controller bindings

[Marek Vasut]

On 12/05/2018 09:39 AM, masonccyang@xxxxxxxxxxx wrote:
> Hi Marek,

Hi,

>> "Marek Vasut" <marek.vasut@xxxxxxxxx>
>> 2018/12/05 上午 10:04
>>
>> To
>>
>> "Mason Yang" <masonccyang@xxxxxxxxxxx>, broonie@xxxxxxxxxx, linux-
>> kernel@xxxxxxxxxxxxxxx, linux-spi@xxxxxxxxxxxxxxx,
>> boris.brezillon@xxxxxxxxxxx, linux-renesas-soc@xxxxxxxxxxxxxxx,
>> "Geert Uytterhoeven" <geert+renesas@xxxxxxxxx>,
>>
>> cc
>>
>> juliensu@xxxxxxxxxxx, "Simon Horman" <horms@xxxxxxxxxxxx>,
>> zhengxunli@xxxxxxxxxxx
>>
>> Subject
>>
>> Re: [PATCH v2 2/2] dt-binding: spi: Document Renesas R-Car Gen3 RPC
>> controller bindings
>>
>> On 12/03/2018 10:18 AM, Mason Yang wrote:
>> > Document the bindings used by the Renesas R-Car Gen3 RPC SPI controller.
>>
>> RPC is SPI and HF controller, it is not a pure SPI controller.
>>
>> How does this deal with the HF part ? Keep in mind the bindings are ABI
>> and it will be difficult to redo them later.
> 
> After checking HF datasheet,
> 512_MBIT_256_MBIT_128_MBIT_HYPERFLASH_FAMILY_Datasheet.pdf.
> 
> 
> 
> From my point of view,
> HyperFlash is a kind of standard NOR Flash with high-speed SPI interface.
> But I might be wrong.
It behaves as a Parallel CFI NOR internally, and so it fits and works
with the CFI NOR drivers (see the U-Boot driver), except the interface
between the HF controller and the chip is custom. It's not SPI per-se.

-- 
Best regards,
Marek Vasut