Re: [PATCH V8 1/2] mtd: spi-nor: Bindings for Cadence Quad SPI Flash Controller driver.

[Marek Vasut <marex@denx.de>]

On Thursday, February 04, 2016 at 08:38:47 AM, Vignesh R wrote:
> On 02/02/2016 02:43 AM, Marek Vasut wrote:
> > On Monday, February 01, 2016 at 10:03:35 PM, Brian Norris wrote:
> >> On Wed, Jan 13, 2016 at 03:39:17AM +0100, Marek Vasut wrote:
> >>> On Wednesday, January 13, 2016 at 03:26:08 AM, Rob Herring wrote:
> >>>> On Mon, Jan 11, 2016 at 05:34:45AM +0100, Marek Vasut wrote:
> [...]
> 
> >>> All these SoCs should be capable of tweaking the block to fit their
> >>> needs by just the DT properties. I believe they differ only in the
> >>> FIFO depth and sometimes someone is greedy and uses 4:16 CS
> >>> multiplexer, which is an external passive component, but that's all.
> >>> 
> >>> Would we need soc-specific compatible strings if this is the case?
> >> 
> >> It's nice when most things can be supported with a small set of DT
> >> properties, as you've done. But IUIC, I think it's usually good practice
> >> to define and use SoC-specific (or maybe SoC family) compatible strings
> >> in the docs and DTS files, in addition to the generic one, in case there
> >> are future quirks that need to be handled. Note that you don't actually
> >> have to use these in the driver yet, but it's good to have a definition.
> >> 
> >> So you can, today, have:
> >> 	foo@xxxx {
> >> 	
> >> 		compatible = "ti,baz-12345", "cdns,qspi-nor";
> >> 		...
> >> 	
> >> 	};
> >> 
> >> And we have the option to pick up "ti,baz-12345" in the Linux driver *if
> >> needed.*
> 
> The support for TI SoC that has this IP is not in upstream yet. I will
> add TI-specific compatible later. It will be:
> 
> 	foo@xxxx {
> 		compatible = "ti,k2g-qspi", "cdns,qspi-nor";
>  		...
>  	};

Do you expect any specifics which cannot be handled by the current bindings btw?
In my socfpga case, the compatible strings will be probably:

"altr,socfpga-gen5-qspi"

Dinh, Graham, do you agree with this or should we use something else ?

Thanks!

Best regards,
Marek Vasut