Re: [PATCH v5 5/6] dt-bindings: spi: Convert cadence-quadspi.txt to cadence-quadspi.yaml

[Ramuthevar, Vadivel MuruganX]

Hi,

On 5/11/2020 3:14 pm, Linus Walleij wrote:
> On Thu, Oct 29, 2020 at 8:39 AM Ramuthevar,Vadivel MuruganX
> <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx> wrote:
>
> > From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>
> >
> > Convert the cadence-quadspi.txt documentation to cadence-quadspi.yaml
> > remove the cadence-quadspi.txt from Documentation/devicetree/bindings/spi/
> >
> > Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>
>
> > +  cdns,is-decoded-cs:
> > +    type: boolean
> > +    description:
> > +      Flag to indicate whether decoder is used or not.
>
> Please elaborate a bit on what kind of decoder this is.
> I am curious! :)
Sure, I will elaborate more about decoder for chip select.

QSPI controller has in-built chip select decoder instead of external 
decder circuit, it supports multiple chip selection by 2-to-4 decoder, 
the below combinations
CS0 - 1110
CS1 - 1101
CS2 - 1011
CS3 - 0111

when in direct access mode, each chip selection has it's own specified 
memory region as well.

Regards
Vadivel
> Yours,
> Linus Walleij