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* [PATCH] arch: arm64: dts: add delay between CS and CLK signal for flash device
@ 2021-11-03  3:38 Meng Li
  2021-11-15  2:19 ` Li, Meng
  2021-11-21  9:17 ` Shawn Guo
  0 siblings, 2 replies; 3+ messages in thread
From: Meng Li @ 2021-11-03  3:38 UTC (permalink / raw)
  To: shawnguo, leoyang.li, robh+dt
  Cc: linux-kernel, linux-arm-kernel, devicetree, meng.li

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


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* RE: [PATCH] arch: arm64: dts: add delay between CS and CLK signal for flash device
  2021-11-03  3:38 [PATCH] arch: arm64: dts: add delay between CS and CLK signal for flash device Meng Li
@ 2021-11-15  2:19 ` Li, Meng
  2021-11-21  9:17 ` Shawn Guo
  1 sibling, 0 replies; 3+ messages in thread
From: Li, Meng @ 2021-11-15  2:19 UTC (permalink / raw)
  To: shawnguo, leoyang.li, robh+dt; +Cc: linux-kernel, linux-arm-kernel, devicetree

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


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] arch: arm64: dts: add delay between CS and CLK signal for flash device
  2021-11-03  3:38 [PATCH] arch: arm64: dts: add delay between CS and CLK signal for flash device Meng Li
  2021-11-15  2:19 ` Li, Meng
@ 2021-11-21  9:17 ` Shawn Guo
  1 sibling, 0 replies; 3+ messages in thread
From: Shawn Guo @ 2021-11-21  9:17 UTC (permalink / raw)
  To: Meng Li; +Cc: leoyang.li, robh+dt, linux-kernel, linux-arm-kernel, devicetree

On Wed, Nov 03, 2021 at 11:38:38AM +0800, Meng Li wrote:
> 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>

Updated the subject as below and applied the patch.

  arm64: dts: fsl-ls1043a-rdb: add delay between CS and CLK signal for flash device

Shawn

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2021-11-21  9:17 UTC | newest]

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2021-11-03  3:38 [PATCH] arch: arm64: dts: add delay between CS and CLK signal for flash device Meng Li
2021-11-15  2:19 ` Li, Meng
2021-11-21  9:17 ` Shawn Guo

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