Re: [PATCH v3] arm64: dts: ti: k3-j721s2-main: Enable support for SDR104 speed mode

[Kumar, Udit]

On 9/20/2023 3:11 PM, Bhavya Kapoor wrote:
> According to TRM for J721S2, SDR104 speed mode is supported by the SoC
> but its capabilities were masked in device tree. Remove sdhci-caps-mask
> to enable support for SDR104 speed mode for SD card in J721S2 SoC. Also
> add itap delay select value for DDR50 High Speed Mode.
>
> [+] Refer to : section 12.3.6.1.1 MMCSD Features, in J721S2 TRM
> - https://www.ti.com/lit/zip/spruj28
>
> Fixes: b8545f9d3a54 ("arm64: dts: ti: Add initial support for J721S2 SoC")
> Signed-off-by: Bhavya Kapoor <b-kapoor@xxxxxx>
> Reviewed-by: Udit Kumar <u-kumar1@xxxxxx>
> ---
>
> Changelog v2->v3:
>   - Add Itap Delay Select value for DDR50 SD High Speed Mode
>
> Link to v2 patch : https://lore.kernel.org/all/20230412121415.860447-1-b-kapoor@xxxxxx/
>
>   arch/arm64/boot/dts/ti/k3-j721s2-main.dtsi | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/ti/k3-j721s2-main.dtsi b/arch/arm64/boot/dts/ti/k3-j721s2-main.dtsi
> index 084f8f5b6699..a5ab301b14f1 100644
> --- a/arch/arm64/boot/dts/ti/k3-j721s2-main.dtsi
> +++ b/arch/arm64/boot/dts/ti/k3-j721s2-main.dtsi
> @@ -766,11 +766,10 @@ main_sdhci1: mmc@4fb0000 {
>   		ti,itap-del-sel-sd-hs = <0x0>;
>   		ti,itap-del-sel-sdr12 = <0x0>;
>   		ti,itap-del-sel-sdr25 = <0x0>;
> +		ti,itap-del-sel-ddr50 = <0x2>;

Please elaborate , why we need itap delay

As per v2 
https://lore.kernel.org/all/d85fbd74-6470-f664-2eb6-ee02b8135b23@xxxxxx/

there should not be any change in tap delay


>   		ti,clkbuf-sel = <0x7>;
>   		ti,trm-icp = <0x8>;
>   		dma-coherent;
> -		/* Masking support for SDR104 capability */
> -		sdhci-caps-mask = <0x00000003 0x00000000>;
>   		status = "disabled";
>   	};
>