RE: [PATCH] arch: arm64: dts: add delay between CS and CLK signal for flash device

[Li, Meng]

Is there any comments about this patch?

Thanks,
Limeng

> -----Original Message-----
> From: Li, Meng <Meng.Li@xxxxxxxxxxxxx>
> Sent: Wednesday, November 3, 2021 11:39 AM
> To: shawnguo@xxxxxxxxxx; leoyang.li@xxxxxxx; robh+dt@xxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; Li, Meng <Meng.Li@xxxxxxxxxxxxx>
> Subject: [PATCH] arch: arm64: dts: add delay between CS and CLK signal for
> flash device
> 
> Based on commit d59c90a2400f("spi: spi-fsl-dspi: Convert TCFQ users to XSPI
> FIFO mode ") and 6c1c26ecd9a3("spi:
> spi-fsl-dspi: Accelerate transfers using larger word size if possible"), on
> ls1043a-rdb platform, the spi work mode is changed from TCFQ mode to XSPI
> mode. In order to keep the transmission sequence matches with flash device,
> it is need to add delay between CS and CLK signal.
> The strategy of generating delay value refers to QorIQ LS1043A Reference
> Manual.
> 
> Signed-off-by: Meng Li <Meng.Li@xxxxxxxxxxxxx>
> ---
>  arch/arm64/boot/dts/freescale/fsl-ls1043a-rdb.dts | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/freescale/fsl-ls1043a-rdb.dts
> b/arch/arm64/boot/dts/freescale/fsl-ls1043a-rdb.dts
> index 3a669238a0b8..3b1a31a063c6 100644
> --- a/arch/arm64/boot/dts/freescale/fsl-ls1043a-rdb.dts
> +++ b/arch/arm64/boot/dts/freescale/fsl-ls1043a-rdb.dts
> @@ -98,6 +98,8 @@
>  		compatible = "n25q128a13", "jedec,spi-nor";  /* 16MB */
>  		reg = <0>;
>  		spi-max-frequency = <1000000>; /* input clock */
> +		fsl,spi-cs-sck-delay = <100>;
> +		fsl,spi-sck-cs-delay = <100>;
>  	};
> 
>  	slic@2 {
> --
> 2.17.1