RE: [PATCH 2/2] arm64: dts: imx8mm/mn/mp: limit the max frequency of spi nor chip
From: Bough Chen
Date: Tue Sep 16 2025 - 06:04:09 EST
> -----Original Message-----
> From: Fabio Estevam <festevam@xxxxxxxxx>
> Sent: 2025年9月16日 17:42
> To: Bough Chen <haibo.chen@xxxxxxx>
> Cc: Rob Herring <robh@xxxxxxxxxx>; Krzysztof Kozlowski <krzk+dt@xxxxxxxxxx>;
> Conor Dooley <conor+dt@xxxxxxxxxx>; Shawn Guo <shawnguo@xxxxxxxxxx>;
> Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>; Pengutronix Kernel Team
> <kernel@xxxxxxxxxxxxxx>; devicetree@xxxxxxxxxxxxxxx; imx@xxxxxxxxxxxxxxx;
> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH 2/2] arm64: dts: imx8mm/mn/mp: limit the max frequency
> of spi nor chip
>
> Hi Haibo,
>
> On Tue, Sep 16, 2025 at 5:57 AM Haibo Chen <haibo.chen@xxxxxxx> wrote:
> >
> > The spi nor on imx8mm/mn/mp evk board works under SDR mode, and driver
> > use FlexSPIn_MCR0[RXCLKSRC] = 0x0 for SDR mode.
> > According to the datasheet, there is IO limitation on these chips, the
> > max frequency of such case is 66MHz, so add the limatation here
>
> Typo: limitation.
>
> > to align with datasheet.
> >
> > Refer to 3.9.9 FlexSPI timing parameters on page 65.
> > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.
> >
> nxp.com%2Fdocs%2Fen%2Fdata-sheet%2FIMX8MNCEC.pdf&data=05%7C02%7
> Chaibo.
> >
> chen%40nxp.com%7Ce6a75800d66b428dc03b08ddf50552ef%7C686ea1d3bc2b
> 4c6fa9
> >
> 2cd99c5c301635%7C0%7C1%7C638936125394709166%7CUnknown%7CTWFpb
> GZsb3d8ey
> >
> JFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTW
> Fp
> >
> bCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=%2Fn5dKo9EZdOY7I%2BaGk0
> oX4N%2B
> > dPZktHrpzYyDljCW5zc%3D&reserved=0
>
> Fixes tag?
Though the original clock setting still can work, yes, it's better to add fix tag here.
Thanks
Haibo Chen