2023-09-20 10:00:33

by Bhavya Kapoor

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

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 <[email protected]>
Reviewed-by: Udit Kumar <[email protected]>
---

Changelog v2->v3:
- Add Itap Delay Select value for DDR50 SD High Speed Mode

Link to v2 patch : https://lore.kernel.org/all/[email protected]/

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

--
2.39.2

2023-09-20 12:12:35

by Kumar, Udit

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

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 <[email protected]>
> Reviewed-by: Udit Kumar <[email protected]>
> ---
>
> Changelog v2->v3:
> - Add Itap Delay Select value for DDR50 SD High Speed Mode
>
> Link to v2 patch : https://lore.kernel.org/all/[email protected]/
>
> 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/[email protected]/

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";
> };
>