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

Li, Meng
2021-11-15T02:20:09Z

Is there any comments about this patch?

Thanks,
Limeng

> -----Original Message-----
> From: Li, Meng <Meng.Li@windriver.com>
> Sent: Wednesday, November 3, 2021 11:39 AM
> To: shawnguo@kernel.org; leoyang.li@nxp.com; robh+dt@kernel.org
> Cc: linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> devicetree@vger.kernel.org; Li, Meng <Meng.Li@windriver.com>
> 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@windriver.com>
> ---
> 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