atmel_sdhci: SDMMC_CD pin still needed for card detection despite EMMC set to non-removable

[Eugen Hristev]

Hi Zixun Li,

On 4/27/23 22:51, Zixun Li wrote:
> Hardware: SAMA5D27 customized board, EMMC connected to SDMMC0. SDMMC0_CD pin pulled-down for BootROM card detection, once booted it used as LED output.
> 
> Software: u-boot-at91 76f7f55
> 
> Issue:
> U-Boot can't detect EMMC despite it set to non-removable in DT, unless SDMMC0_CD pin is used (so this pin can't be used for other purpose)
> 
> sdmmc0: sdio-host at a0000000 {
>                                                  bus-width = <4>;
>                                                  pinctrl-names = "default";
>                                                  pinctrl-0 = <&pinctrl_sdmmc0_default>;
>                                                  status = "okay";
>                                                  non-removable;
>                                                  no-1-8-v;
>                                  };
> 
> Workaround: I have to FCD bit of SDMMC_MC1R register.
> 
> diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c
> index 766e4a6b0c..89ceeaf3c1 100644
> --- a/drivers/mmc/sdhci.c
> +++ b/drivers/mmc/sdhci.c
> @@ -758,7 +758,12 @@ static int sdhci_get_cd(struct udevice *dev)
> 
>          /* If nonremovable, assume that the card is always present. */
>          if (mmc->cfg->host_caps & MMC_CAP_NONREMOVABLE)
> +       {
> +               value = sdhci_readb(host, SDHCI_HOST_MC1R);
> +               sdhci_writeb(host, SDHCI_VENDOR_MC1R_FCD | value, SDHCI_HOST_MC1R);
>                  return 1;
> +       }
> +

Can you find some place to set this bit in the atmel sdhci driver, and 
not in the core?
The MC1R register is specific to at91 device.

Eugen

>          /* If polling, assume that the card is always present. */
>          if (mmc->cfg->host_caps & MMC_CAP_NEEDS_POLL)
>                  return 1;
> diff --git a/include/sdhci.h b/include/sdhci.h
> index c718dd7206..61e7ebb2a1 100644
> --- a/include/sdhci.h
> +++ b/include/sdhci.h
> @@ -223,6 +223,9 @@
> 
> #define SDHCI_GET_VERSION(x) (x->version & SDHCI_SPEC_VER_MASK)
> 
> +#define SDHCI_HOST_MC1R                        0x204
> +
> +#define SDHCI_VENDOR_MC1R_FCD  0x80
> /*
>    * End of controller registers.
>    */
>