Re: [PATCH v12 2/7] mmc: k1: add sdhci platform driver

[Yao Zi <me@ziyao.cc>]

On Sun, Sep 06, 2026 at 05:11:04PM +0800, Eric Chung wrote:
> Add SDHCI platform driver support for SpacemiT K1 SoC. This driver
> implements the necessary platform-specific operations for the SDHCI
> controller, enabling MMC/SD card functionality on K1-based platforms.
> 
> Signed-off-by: Eric Chung <eric.chung@riscstar.com>
> 
> ---
> v9:
> - Disable CMD18 (multiple-block read) for SD cards in SPL.
> v6:
> - Remove ".data = 0" in spacemit_sdhci_ids[].
> v5:
> - Remove MMC_CAP_CMD23 as the CMD23 support is now a separate series.
> - Use tabs for macro definition alignment.
> - Use read_poll_timeout().
> - Set pinctrl state based on selected timing mode.
> - Add the definition of SDHC_DLL_REG1_HS400_VAL.
> - Remove the condition based on quirks.
> v4:
> - Add bulk release operations on reset and clock.
> v3:
> - Enable CMD23 in capability.
> v2:
> - Enable ADMA mode support.
> - Use CMD23 for multi-block read/write.
> - Move ASR/AIB register into pinctrl driver.
> - Correct pinctrl state from "fast" to "uhs".
> - Migrate tuning support from the spacemit linux driver.
> ---
>  drivers/mmc/Kconfig          |   7 +
>  drivers/mmc/Makefile         |   1 +
>  drivers/mmc/spacemit_sdhci.c | 684 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 692 insertions(+)

...

> diff --git a/drivers/mmc/spacemit_sdhci.c b/drivers/mmc/spacemit_sdhci.c
> new file mode 100644
> index 000000000000..4731c9ca0832
> --- /dev/null
> +++ b/drivers/mmc/spacemit_sdhci.c
> @@ -0,0 +1,684 @@

...

> +#define SPACEMIT_RX_DLINE_REG		9

There's an on-going series containing fixes for SpacemiT MMC controllers
in Linux upstream, and I noticed this patch carries same issues for the
delay granularity[1] and minimum RX tuning window[2]. Should it be fixed?

...

> +static int spacemit_sdhci_execute_tuning(struct mmc *mmc, u8 opcode)
> +{

...

> +	if (max_pass_len < 3) {
> +		log_err("Tuning failed: no stable window found\n");
> +		return -EIO;
> +	}

and here.

Best regards,
Yao Zi

[1]: https://lore.kernel.org/spacemit/20260902-07-k3-sdhci-fix-v1-5-b15c5d0f64fd@kernel.org/
[2]: https://lore.kernel.org/spacemit/20260902-07-k3-sdhci-fix-v1-6-b15c5d0f64fd@kernel.org/