[PATCH v2 2/4] arm64: dts: imx8mn-evk: limit the max frequency of spi nor chip

Haibo Chen posted 4 patches 2 weeks, 1 day ago
[PATCH v2 2/4] arm64: dts: imx8mn-evk: limit the max frequency of spi nor chip
Posted by Haibo Chen 2 weeks, 1 day ago
The spi nor on imx8mn 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 this chip,
the max frequency of such case is 66MHz, so add the limitation
here to align with datasheet.

Refer to 3.9.9 FlexSPI timing parameters on page 65.
https://www.nxp.com/docs/en/data-sheet/IMX8MNCEC.pdf

Fixes: 579df4288896 ("arm64: dts: imx8mn-evk: add QSPI flash")
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
---
 arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi b/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi
index 145355ff91b454795478b504eb403b0590848d46..fa43238e7b917a5b5f0bd9af96bd900f6dbacb8d 100644
--- a/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi
@@ -199,7 +199,7 @@ flash0: flash@0 {
 		reg = <0>;
 		#address-cells = <1>;
 		#size-cells = <1>;
-		spi-max-frequency = <166000000>;
+		spi-max-frequency = <66000000>;
 		spi-tx-bus-width = <4>;
 		spi-rx-bus-width = <4>;
 	};

-- 
2.34.1
Re: [PATCH v2 2/4] arm64: dts: imx8mn-evk: limit the max frequency of spi nor chip
Posted by Frank Li 2 weeks ago
On Wed, Sep 17, 2025 at 04:42:28PM +0800, Haibo Chen wrote:
> The spi nor on imx8mn 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 this chip,

'chip' means spi-nor flash or imx8mn SoC? Looks like it is 8mn according
to below refers. can you change 'chip' to i.MX8MN

> the max frequency of such case is 66MHz, so add the limitation
> here to align with datasheet.
>
> Refer to 3.9.9 FlexSPI timing parameters on page 65.
> https://www.nxp.com/docs/en/data-sheet/IMX8MNCEC.pdf
>
> Fixes: 579df4288896 ("arm64: dts: imx8mn-evk: add QSPI flash")
> Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
> ---
>  arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi b/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi
> index 145355ff91b454795478b504eb403b0590848d46..fa43238e7b917a5b5f0bd9af96bd900f6dbacb8d 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi
> @@ -199,7 +199,7 @@ flash0: flash@0 {
>  		reg = <0>;
>  		#address-cells = <1>;
>  		#size-cells = <1>;
> -		spi-max-frequency = <166000000>;
> +		spi-max-frequency = <66000000>;

Looks like flash's limiation, any common property in spi controller to limit
frequency?

Frank
>  		spi-tx-bus-width = <4>;
>  		spi-rx-bus-width = <4>;
>  	};
>
> --
> 2.34.1
>