Hello Sascha,
On 5/11/26 2:08 PM, Sascha Hauer wrote:
> Implement the hs400_enhanced_strobe op so the dwcmshc controller
> samples on the eMMC strobe instead of the source clock when in
> HS400ES. The bit lives at EMMC_CONTROL[8] (DWCMSHC_ENHANCED_STROBE)
> in the same vendor area register that already holds CARD_IS_EMMC.
>
> Assisted-by: Claude Opus 4.7 <[email protected]>
> Signed-off-by: Sascha Hauer <[email protected]>
> ---
> drivers/mci/rockchip-dwcmshc-sdhci.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/drivers/mci/rockchip-dwcmshc-sdhci.c
> b/drivers/mci/rockchip-dwcmshc-sdhci.c
> index 3aa3f12930..89bc4781b4 100644
> --- a/drivers/mci/rockchip-dwcmshc-sdhci.c
> +++ b/drivers/mci/rockchip-dwcmshc-sdhci.c
> @@ -19,6 +19,7 @@
> #define DWCMSHC_HOST_CTRL3 0x508
> #define DWCMSHC_EMMC_CONTROL 0x52c
> #define DWCMSHC_CARD_IS_EMMC BIT(0)
> +#define DWCMSHC_ENHANCED_STROBE BIT(8)
> #define DWCMSHC_EMMC_ATCTRL 0x540
>
> /* Rockchip specific Registers */
> @@ -363,12 +364,24 @@ static int rk_sdhci_execute_tuning(struct mci_host
> *mci, u32 opcode)
> return sdhci_execute_tuning(&host->sdhci, opcode);
> }
>
> +static void rk_sdhci_hs400_enhanced_strobe(struct mci_host *mci,
> + struct mci_ios *ios)
> +{
> + struct rk_sdhci_host *host = to_rk_sdhci_host(mci);
> + u32 val;
> +
> + val = sdhci_read32(&host->sdhci, DWCMSHC_EMMC_CONTROL);
> + val |= DWCMSHC_ENHANCED_STROBE;
> + sdhci_write32(&host->sdhci, DWCMSHC_EMMC_CONTROL, val);
Linux checks ios->enhanced strobe and disables/enables the strobe based
on that. I think that's useful for barebox as well, so the core has a
chance to implement fallback.
Cheers,
Ahmad
> +}
> +
> static const struct mci_ops rk_sdhci_ops = {
> .send_cmd = rk_sdhci_send_cmd,
> .set_ios = rk_sdhci_set_ios,
> .init = rk_sdhci_init,
> .card_present = rk_sdhci_card_present,
> .execute_tuning = rk_sdhci_execute_tuning,
> + .hs400_enhanced_strobe = rk_sdhci_hs400_enhanced_strobe,
> };
>
> static int rk_sdhci_probe(struct device *dev)
>
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