Re: [PATCH v2 09/15] arm64: dts: freescale: imx93-phyboard-segin: Fix for ERR052021 errata

[Frank Li <Frank.li@nxp.com>]

On Tue, Apr 15, 2025 at 06:33:05AM +0200, Primoz Fiser wrote:

subject should be

"set SION bit for CMD/DATA to fix ERR052021 errata"

> Implement fix for i.MX 93 silicon errata ERR052021:
>
> ERR052021 uSDHC: Sometimes uSDHC does not work under VDD_SOC low
> 		 drive mode and nominal mode
> Description:
> uSDHC PADs have one integration issue.
> When CMD/DATA lines direction change from output to input, uSDHC
> controller begin sampling, the integration issue will make input
> enable signal from uSDHC propagated to the PAD with a long delay,
> thus the new input value on the pad comes to uSDHC lately. The
> uSDHC sampled the old input value and the sampling result is wrong.
>

nit:
  add 2 char indention

> Workaround:
> Set uSDHC CMD/DATA PADs iomux register SION bit to 1, then PADs will
> propagate input to uSDHC with no delay, so correct value is sampled.

the same here

>
> This issue will wrongly trigger the start bit when sample the USDHC
> command response, cause the USDHC trigger command CRC/index/endbit
> error, which will finally impact the tuning pass window, espically
> will impact the standard tuning logic, and can't find a correct delay
> cell to get the best timing.
>
> Based on commit bb89601282fc ("arm64: dts: imx93-11x11-evk: set SION for
> cmd and data pad of USDHC").
>
> Signed-off-by: Primoz Fiser <primoz.fiser@norik.com>
> ---
> Changes in v2:
> - new patch in v2 (split from #8)
>
>  .../dts/freescale/imx93-phyboard-segin.dts    | 37 ++++++++++---------
>  1 file changed, 20 insertions(+), 17 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx93-phyboard-segin.dts b/arch/arm64/boot/dts/freescale/imx93-phyboard-segin.dts
> index 541297052b62..525f52789f8b 100644
> --- a/arch/arm64/boot/dts/freescale/imx93-phyboard-segin.dts
> +++ b/arch/arm64/boot/dts/freescale/imx93-phyboard-segin.dts
> @@ -75,39 +75,42 @@ MX93_PAD_SD2_CD_B__GPIO3_IO00		0x31e
>  		>;
>  	};
>
> +	/* need to config the SION for data and cmd pad, refer to ERR052021 */
>  	pinctrl_usdhc2_default: usdhc2grp {
>  		fsl,pins = <
>  			MX93_PAD_SD2_CLK__USDHC2_CLK		0x159e
> -			MX93_PAD_SD2_CMD__USDHC2_CMD		0x139e
> -			MX93_PAD_SD2_DATA0__USDHC2_DATA0	0x138e
> -			MX93_PAD_SD2_DATA1__USDHC2_DATA1	0x138e
> -			MX93_PAD_SD2_DATA2__USDHC2_DATA2	0x138e
> -			MX93_PAD_SD2_DATA3__USDHC2_DATA3	0x139e
> +			MX93_PAD_SD2_CMD__USDHC2_CMD		0x4000139e
> +			MX93_PAD_SD2_DATA0__USDHC2_DATA0	0x4000138e
> +			MX93_PAD_SD2_DATA1__USDHC2_DATA1	0x4000138e
> +			MX93_PAD_SD2_DATA2__USDHC2_DATA2	0x4000138e
> +			MX93_PAD_SD2_DATA3__USDHC2_DATA3	0x4000139e
>  			MX93_PAD_SD2_VSELECT__USDHC2_VSELECT	0x51e
>  		>;
>  	};
>
> +	/* need to config the SION for data and cmd pad, refer to ERR052021 */
>  	pinctrl_usdhc2_100mhz: usdhc2-100mhzgrp {
>  		fsl,pins = <
>  			MX93_PAD_SD2_CLK__USDHC2_CLK		0x159e
> -			MX93_PAD_SD2_CMD__USDHC2_CMD            0x139e
> -			MX93_PAD_SD2_DATA0__USDHC2_DATA0        0x138e
> -			MX93_PAD_SD2_DATA1__USDHC2_DATA1        0x138e
> -			MX93_PAD_SD2_DATA2__USDHC2_DATA2        0x139e
> -			MX93_PAD_SD2_DATA3__USDHC2_DATA3        0x139e
> -			MX93_PAD_SD2_VSELECT__USDHC2_VSELECT    0x51e
> +			MX93_PAD_SD2_CMD__USDHC2_CMD		0x4000139e
> +			MX93_PAD_SD2_DATA0__USDHC2_DATA0	0x4000138e
> +			MX93_PAD_SD2_DATA1__USDHC2_DATA1	0x4000138e
> +			MX93_PAD_SD2_DATA2__USDHC2_DATA2	0x4000139e
> +			MX93_PAD_SD2_DATA3__USDHC2_DATA3	0x4000139e
> +			MX93_PAD_SD2_VSELECT__USDHC2_VSELECT	0x51e
>  		>;
>  	};
>
> +	/* need to config the SION for data and cmd pad, refer to ERR052021 */
>  	pinctrl_usdhc2_200mhz: usdhc2-200mhzgrp {
>  		fsl,pins = <
>  			MX93_PAD_SD2_CLK__USDHC2_CLK		0x158e
> -			MX93_PAD_SD2_CMD__USDHC2_CMD            0x139e
> -			MX93_PAD_SD2_DATA0__USDHC2_DATA0        0x139e
> -			MX93_PAD_SD2_DATA1__USDHC2_DATA1        0x139e
> -			MX93_PAD_SD2_DATA2__USDHC2_DATA2        0x139e
> -			MX93_PAD_SD2_DATA3__USDHC2_DATA3        0x139e
> -			MX93_PAD_SD2_VSELECT__USDHC2_VSELECT    0x51e
> +			MX93_PAD_SD2_CMD__USDHC2_CMD		0x4000139e
> +			MX93_PAD_SD2_DATA0__USDHC2_DATA0	0x4000139e
> +			MX93_PAD_SD2_DATA1__USDHC2_DATA1	0x4000139e
> +			MX93_PAD_SD2_DATA2__USDHC2_DATA2	0x4000139e
> +			MX93_PAD_SD2_DATA3__USDHC2_DATA3	0x4000139e
> +			MX93_PAD_SD2_VSELECT__USDHC2_VSELECT	0x51e
>  		>;
>  	};
>  };
> --
> 2.34.1
>