STM32H757I-EVAL: implement MFX support (for SDMMC card detect)

[erwango]

Discussed in #97713

^{Originally posted by WHMJJ October 16, 2025}

Is your feature request related to a problem? Please describe.

Hi Zephyr team,

I’m using the STM32H757I-EVAL board to read data from a microSD card and found that the DK uses the IP4856CX25 level shifter to communicate with the SD card.
However, in the stm32h757i_eval_stm32h757xx_m7.dts file, the SDMMC interface is configured only in 8-bit / CLK / CMD mode, which is not consistent with the actual hardware setup.

I’ve tried modifying the configuration through an overlay, but it still doesn’t work.
Is there any code example available for this board’s SD card configuration, or any guidance on how to port this function properly?

DK:STM32H757I-EVAL
Code:.\zephyrproject\zephyr\samples\subsys\fs\fs_sample

&sdmmc1 {
    status = "okay";
    compatible = "st,stm32-sdmmc";    
    pinctrl-0 = <
        &sdmmc1_d0_pc8
        &sdmmc1_d1_pc9
        &sdmmc1_d2_pc10
        &sdmmc1_d3_pc11
        &sdmmc1_ck_pc12
        &sdmmc1_cmd_pd2
        &sdmmc1_d0dir_pc6
        &sdmmc1_d123dir_pc7
        &sdmmc1_ckin_pb8
        &sdmmc1_cdir_pb9
    >;
     pinctrl-names = "default";

    /*change the MXF pin to PF5 */
   cd-gpios = <&gpiof 5 GPIO_ACTIVE_LOW>;

    disk-name = "TEST-SD";
};

Error msg as below

�[1;31m main: Storage init ERROR!�[0m
�[1;31m fs: fs mount error (-19)�[0m Error mounting disk.
[1;31m fs: fs not mounted (mp == 0x24000000)�

Best regard,
Joey

Describe the solution you'd like

1.The SD card pin setting with IP4856CX25_C/MFX
2.Or bypass the MFX use another pin for card detect

Describe alternatives you've considered

No response

[erwango]

@WHMJJ as discussed, SDMMC support would require to add support for IP4856CX25_C/MFX for which we could find similar design introduced with #82604.

[mathieuchopstm]

Can't remove issue from NXP Platforms project. I'm not sure why the NXP tag was added in the first place? @cfriedt