[PATCH] mmc: cv1800b_sdhci: configure SDHCI PHY

[PATCH] mmc: cv1800b_sdhci: configure SDHCI PHY

[Andrei Lalaev]

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 <andrey.lalaev@gmail.com>
Link: https://lore.kernel.org/u-boot/20260822091510.3253162-1-andrey.lalaev@gmail.com/
---
 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,
 };
 
 static int cv1800b_sdhci_bind(struct udevice *dev)

---
base-commit: 509312dc5386ff4c5adabf53a573abca0aac4ce5
change-id: 20260907-milkv-duo-sdhci-configure-aa9790c73d0b

Best regards,
--  
Andrei Lalaev <andrey.lalaev@gmail.com>

Re: [PATCH] mmc: cv1800b_sdhci: configure SDHCI PHY

[Yao Zi]

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 <andrey.lalaev@gmail.com>
> Link: https://lore.kernel.org/u-boot/20260822091510.3253162-1-andrey.lalaev@gmail.com/
> ---
>  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.

Best regards,
Yao Zi

Re: [PATCH] mmc: cv1800b_sdhci: configure SDHCI PHY

[Andrei Lalaev]

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 <andrey.lalaev@gmail.com>
>> Link: https://lore.kernel.org/u-boot/20260822091510.3253162-1-andrey.lalaev@gmail.com/
>> ---
>>  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

Re: [PATCH] mmc: cv1800b_sdhci: configure SDHCI PHY

[Andrei Lalaev]

On 07.09.26 20:44, Andrei Lalaev wrote:
> 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 <andrey.lalaev@gmail.com>
>>> Link: https://lore.kernel.org/u-boot/20260822091510.3253162-1-andrey.lalaev@gmail.com/
>>> ---
>>>  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.
> 
> 

I've rechecked, and unfortunately, moving it to cv1800b_sdhci_reset() is not
an option because reset is called only from cv1800b_execute_tuning() and
not accessible to SDHCI core (unlike in Linux MMC subsystem).

So I think I'll just drop deferred_probe() (wasn't actually required)
and call the function directly from probe().


-- 
Best regards,
Andrei Lalaev

Re: [PATCH] mmc: cv1800b_sdhci: configure SDHCI PHY

[Yao Zi]

On Tue, Sep 08, 2026 at 05:27:43PM +0200, Andrei Lalaev wrote:
> On 07.09.26 20:44, Andrei Lalaev wrote:
> > 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 <andrey.lalaev@gmail.com>
> >>> Link: https://lore.kernel.org/u-boot/20260822091510.3253162-1-andrey.lalaev@gmail.com/
> >>> ---
> >>>  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.
> > 
> > 
> 
> I've rechecked, and unfortunately, moving it to cv1800b_sdhci_reset() is not
> an option because reset is called only from cv1800b_execute_tuning() and
> not accessible to SDHCI core (unlike in Linux MMC subsystem).
> 
> So I think I'll just drop deferred_probe() (wasn't actually required)
> and call the function directly from probe().

Sounds reasonable, too. Thanks.

> -- 
> Best regards,
> Andrei Lalaev

Best regards,
Yao Zi