Hi Yao,
On 07.09.26 20:08, Yao Zi wrote:
> On Mon, Sep 07, 2026 at 04:54:35PM +0200, Andrei Lalaev wrote:
>> Some samples of the Milk-V Duo and Duo 256M have issues with SD card
>> communication. As a result, the SD card is not detected, or the correct
>> mode is not selected.
>>
>> Configure SDHCI PHY in the same way as in downstream, to ensure
>> that the PHY is initialized properly.
>>
>> Fixes: eb36f28ff721 ("mmc: cv1800b: Add sdhci driver support for cv1800b
>> SoC")
>> Signed-off-by: Andrei Lalaev <[email protected]>
>> Link:
>> https://lore.kernel.org/u-boot/[email protected]/
>> ---
>> drivers/mmc/cv1800b_sdhci.c | 25 +++++++++++++++++++++++++
>> 1 file changed, 25 insertions(+)
>>
>> diff --git a/drivers/mmc/cv1800b_sdhci.c b/drivers/mmc/cv1800b_sdhci.c
>> index b756649f90f3..5c129682daba 100644
>> --- a/drivers/mmc/cv1800b_sdhci.c
>> +++ b/drivers/mmc/cv1800b_sdhci.c
>> @@ -8,11 +8,17 @@
>> #include <sdhci.h>
>> #include <linux/delay.h>
>>
>> +#define CV18XX_SDHCI_MSHC_CTRL 0x200
>> +#define CV18XX_SDHCI_PHY_CONFIG 0x24c
>> #define SDHCI_PHY_TX_RX_DLY 0x240
>> #define MMC_MAX_CLOCK 375000000
>> #define TUNE_MAX_PHCODE 128
>>
>> #define PHY_TX_SRC_INVERT BIT(8)
>> +#define PHY_RX_SRC_INVERT BIT(24)
>> +
>> +#define CV18XX_LATANCY_1T BIT(1)
>> +#define CV18XX_PHY_TX_BPS BIT(0)
>>
>> struct cv1800b_sdhci_plat {
>> struct mmc_config cfg;
>> @@ -64,10 +70,29 @@ static int cv1800b_execute_tuning(struct mmc *mmc, u8
>> opcode)
>> }
>> #endif
>>
>> +static int cv1800b_deferred_probe(struct sdhci_host *host)
>> +{
>> + u32 val;
>> +
>> + val = sdhci_readl(host, CV18XX_SDHCI_MSHC_CTRL);
>> + val |= CV18XX_LATANCY_1T;
>> + sdhci_writel(host, val, CV18XX_SDHCI_MSHC_CTRL);
>> +
>> + val = sdhci_readl(host, CV18XX_SDHCI_PHY_CONFIG);
>> + val |= CV18XX_PHY_TX_BPS;
>> + sdhci_writel(host, val, CV18XX_SDHCI_PHY_CONFIG);
>> +
>> + val = PHY_TX_SRC_INVERT | PHY_RX_SRC_INVERT;
>> + sdhci_writel(host, val, SDHCI_PHY_TX_RX_DLY);
>> +
>> + return 0;
>> +}
>> +
>> const struct sdhci_ops cv1800b_sdhci_sd_ops = {
>> #if CONFIG_IS_ENABLED(MMC_SUPPORTS_TUNING)
>> .platform_execute_tuning = cv1800b_execute_tuning,
>> #endif
>> + .deferred_probe = cv1800b_deferred_probe,
>
> Is there a reason to create a new function, instead of including the
> logic somewhere already existing, for example, cv1800b_sdhci_reset()?
> It seems to fit in cv1800b_sdhci_reset(), too, if it's for
> initialization of the PHY.
No, there is no particular reason. I simply didn't think about
cv1800b_sdhci_reset (:
Thank you for the hint! I'll check it and will probably move it to reset.
--
Best regards,
Andrei Lalaev
