Re: [PATCH 4/4] arm64: dts: lx2160a: update fspi node

[Boris Brezillon]

On Thu, 4 Oct 2018 09:24:57 +0000
Yogesh Narayan Gaur <yogeshnarayan.gaur@xxxxxxx> wrote:

> Hi Boris,
> 
> > -----Original Message-----
> > From: Boris Brezillon [mailto:boris.brezillon@xxxxxxxxxxx]
> > Sent: Thursday, October 4, 2018 2:48 PM
> > To: Yogesh Narayan Gaur <yogeshnarayan.gaur@xxxxxxx>
> > Cc: linux-mtd@xxxxxxxxxxxxxxxxxxx; marek.vasut@xxxxxxxxx; vigneshr@xxxxxx;
> > linux-spi@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; robh@xxxxxxxxxx;
> > mark.rutland@xxxxxxx; shawnguo@xxxxxxxxxx; linux-arm-
> > kernel@xxxxxxxxxxxxxxxxxxx; computersforpeace@xxxxxxxxx;
> > frieder.schrempf@xxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> > Subject: Re: [PATCH 4/4] arm64: dts: lx2160a: update fspi node
> > 
> > On Thu,  4 Oct 2018 14:18:40 +0530
> > Yogesh Gaur <yogeshnarayan.gaur@xxxxxxx> wrote:
> >   
> > > Flash mt35xu512aba connected to FlexSPI controller supports
> > > 1-1-8 protocol.
> > > Added flag spi-rx-bus-width and spi-tx-bus-width with values as
> > > 8 and 1 respectively for both flashes connected at CS0 and CS1.
> > >
> > > Signed-off-by: Yogesh Gaur <yogeshnarayan.gaur@xxxxxxx>
> > > ---
> > >  arch/arm64/boot/dts/freescale/fsl-lx2160a-rdb.dts | 4 ++++
> > >  1 file changed, 4 insertions(+)
> > >
> > > diff --git a/arch/arm64/boot/dts/freescale/fsl-lx2160a-rdb.dts
> > > b/arch/arm64/boot/dts/freescale/fsl-lx2160a-rdb.dts
> > > index 901ca346..817175a 100644
> > > --- a/arch/arm64/boot/dts/freescale/fsl-lx2160a-rdb.dts
> > > +++ b/arch/arm64/boot/dts/freescale/fsl-lx2160a-rdb.dts
> > > @@ -42,6 +42,8 @@
> > >  		m25p,fast-read;
> > >  		spi-max-frequency = <20000000>;
> > >  		reg = <0>;
> > > +		spi-rx-bus-width = <8>;
> > > +		spi-tx-bus-width = <1>;  
> > 
> > Why 1? The flash is already flagged with SPI_NOR_OCTAL_READ, which means
> > only the read path will use 1-1-8 mode, so you can safely set spi-tx-bus-width

I meant 'set spi-tx-bus-width to 8' here

> > here and let the framework choose the appropriate mode based on the flash
> > capabilities.  
> 
> Ok.
> 
> >   
> > >  	};
> > >
> > >  	mt35xu512aba1: flash@1 {
> > > @@ -51,6 +53,8 @@
> > >  		m25p,fast-read;
> > >  		spi-max-frequency = <20000000>;
> > >  		reg = <1>;
> > > +		spi-rx-bus-width = <8>;
> > > +		spi-tx-bus-width = <1>;
> > >  	};
> > >  };
> > >  
>