Re: [PATCH v3 1/2] dt-bindings: mtd: amlogic,meson-nand: support fields for boot ROM code

[Miquel Raynal]

Hi Arseniy,

avkrasnov@xxxxxxxxxxxxxxxxx wrote on Wed, 10 Apr 2024 17:48:02 +0300:

> Hi,
> 
> On 10.04.2024 13:23, Miquel Raynal wrote:
> > Hi Arseniy,
> > 
> > avkrasnov@xxxxxxxxxxxxxxxxx wrote on Tue, 9 Apr 2024 21:10:24 +0300:
> >   
> >> Boot ROM code on Meson requires that some pages on NAND must be written
> >> in special mode: "short" ECC mode where each block is 384 bytes and
> >> scrambling mode is on. Such pages located with the specified interval
> >> within specified offset. Both interval and offset are located in the
> >> device tree and used by driver if 'nand-is-boot-medium' is set for
> >> NAND chip.
> >>
> >> Signed-off-by: Arseniy Krasnov <avkrasnov@xxxxxxxxxxxxxxxxx>
> >> ---
> >>  .../bindings/mtd/amlogic,meson-nand.yaml           | 14 ++++++++++++++
> >>  1 file changed, 14 insertions(+)
> >>
> >> diff --git a/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.yaml b/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.yaml
> >> index 57b6957c8415..b86a1953056b 100644
> >> --- a/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.yaml
> >> +++ b/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.yaml
> >> @@ -64,11 +64,25 @@ patternProperties:
> >>          items:
> >>            maximum: 0
> >>  
> >> +      amlogic,boot-page-last:
> >> +        $ref: /schemas/types.yaml#/definitions/uint32
> >> +        description:
> >> +          The NFC driver needs this information to select ECC
> >> +          algorithms supported by the boot ROM.  
> > 
> > Shall we have a length rather than the last page?  
> 
> You mean rename it to "amlogic,boot-pages-length" or something like that ? But I think
> length in bytes is useless here:
> 1) boot rom needs that only some single pages are written in special mode (and as I see in
>    vendor's driver it also works in pages).
> 2) NAND driver operates in pages during write/read such pages.
> 
> So length in bytes will be converted to pages anyway.
> 
> What do You think ?

I didn't talk about units :-)

Maybe: amlogic,boot-pages would make sense? But pointing at the last
page seems weird.

Miquèl