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

Yogesh Narayan Gaur
2018-10-04T09:27:07Z

> -----Original Message-----
> From: Boris Brezillon [mailto:boris.brezillon@bootlin.com]
> Sent: Thursday, October 4, 2018 2:56 PM
> To: Yogesh Narayan Gaur <yogeshnarayan.gaur@nxp.com>
> Cc: linux-mtd@lists.infradead.org; marek.vasut@gmail.com; vigneshr@ti.com;
> linux-spi@vger.kernel.org; devicetree@vger.kernel.org; robh@kernel.org;
> mark.rutland@arm.com; shawnguo@kernel.org; linux-arm-
> kernel@lists.infradead.org; computersforpeace@gmail.com;
> frieder.schrempf@exceet.de; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH 4/4] arm64: dts: lx2160a: update fspi node
>
> On Thu, 4 Oct 2018 09:24:57 +0000
> Yogesh Narayan Gaur <yogeshnarayan.gaur@nxp.com> wrote:
>
> > Hi Boris,
> >
> > > -----Original Message-----
> > > From: Boris Brezillon [mailto:boris.brezillon@bootlin.com]
> > > Sent: Thursday, October 4, 2018 2:48 PM
> > > To: Yogesh Narayan Gaur <yogeshnarayan.gaur@nxp.com>
> > > Cc: linux-mtd@lists.infradead.org; marek.vasut@gmail.com;
> > > vigneshr@ti.com; linux-spi@vger.kernel.org;
> > > devicetree@vger.kernel.org; robh@kernel.org; mark.rutland@arm.com;
> > > shawnguo@kernel.org; linux-arm- kernel@lists.infradead.org;
> > > computersforpeace@gmail.com; frieder.schrempf@exceet.de;
> > > linux-kernel@vger.kernel.org
> > > Subject: Re: [PATCH 4/4] arm64: dts: lx2160a: update fspi node
> > >
> > > On Thu, 4 Oct 2018 14:18:40 +0530
> > > Yogesh Gaur <yogeshnarayan.gaur@nxp.com> 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@nxp.com>
> > > > ---
> > > > 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

Yes.

>
> > > 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>;
> > > > };
> > > > };
> > > >
> >