[PATCH 1/2] mmc: dw_mmc: exynos: Add the exynos3250 compatible

[PATCH 1/2] mmc: dw_mmc: exynos: Add the exynos3250 compatible

[Jaehoon Chung]

To check more exactly, add the exynos3250 compatible.
Not use exynos5250 compatibility.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
---
 Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt | 2 ++
 drivers/mmc/host/dw_mmc-exynos.c                         | 7 +++++++
 2 files changed, 9 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
index aad9844..cd22ac9 100644
--- a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
+++ b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
@@ -22,6 +22,8 @@ Required Properties:
 	  specific extensions.
 	- "samsung,exynos7-dw-mshc-smu": for controllers with Samsung Exynos7
 	  specific extensions having an SMU.
+	- "samsung,exynos3250-dw-mshc": for controllers with Samsung Exynos3250
+	  specific extensions.
 
 * samsung,dw-mshc-ciu-div: Specifies the divider value for the card interface
   unit (ciu) clock. This property is applicable only for Exynos5 SoC's and
diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
index 1e75309..1c96218 100644
--- a/drivers/mmc/host/dw_mmc-exynos.c
+++ b/drivers/mmc/host/dw_mmc-exynos.c
@@ -32,6 +32,7 @@ enum dw_mci_exynos_type {
 	DW_MCI_TYPE_EXYNOS5420_SMU,
 	DW_MCI_TYPE_EXYNOS7,
 	DW_MCI_TYPE_EXYNOS7_SMU,
+	DW_MCI_TYPE_EXYNOS3250,
 };
 
 /* Exynos implementation specific driver private data */
@@ -73,6 +74,9 @@ static struct dw_mci_exynos_compatible {
 	}, {
 		.compatible	= "samsung,exynos7-dw-mshc-smu",
 		.ctrl_type	= DW_MCI_TYPE_EXYNOS7_SMU,
+	}, {
+		.compatible	= "samsung,exynos3250-dw-mshc",
+		.ctrl_type	= DW_MCI_TYPE_EXYNOS3250,
 	},
 };
 
@@ -467,6 +471,7 @@ static int dw_mci_exynos_execute_tuning(struct dw_mci_slot *slot)
 	} while (start_smpl != smpl);
 
 	found = dw_mci_exynos_get_best_clksmpl(candiates);
+
 	if (found >= 0) {
 		dw_mci_exynos_set_clksmpl(host, found);
 		priv->tuned_sample = found;
@@ -520,6 +525,8 @@ static const struct of_device_id dw_mci_exynos_match[] = {
 			.data = &exynos_drv_data, },
 	{ .compatible = "samsung,exynos7-dw-mshc-smu",
 			.data = &exynos_drv_data, },
+	{ .compatible = "samsung,exynos3250-dw-mshc",
+			.data = &exynos_drv_data, },
 	{},
 };
 MODULE_DEVICE_TABLE(of, dw_mci_exynos_match);
-- 
1.9.1

[PATCH 2/2] ARM: dts: change the compatible from exynos5250 to exynos3250

[Jaehoon Chung]

To use more excatly, change compatible from exynos5250 to exynos3250.
Exynos3250 and exnos5250 are some difference.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
---
 arch/arm/boot/dts/exynos3250.dtsi | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/exynos3250.dtsi b/arch/arm/boot/dts/exynos3250.dtsi
index 033def4..05ed242 100644
--- a/arch/arm/boot/dts/exynos3250.dtsi
+++ b/arch/arm/boot/dts/exynos3250.dtsi
@@ -333,7 +333,7 @@
 		};
 
 		mshc_0: mshc at 12510000 {
-			compatible = "samsung,exynos5250-dw-mshc";
+			compatible = "samsung,exynos3250-dw-mshc";
 			reg = <0x12510000 0x1000>;
 			interrupts = <0 142 0>;
 			clocks = <&cmu CLK_SDMMC0>, <&cmu CLK_SCLK_MMC0>;
@@ -345,7 +345,7 @@
 		};
 
 		mshc_1: mshc at 12520000 {
-			compatible = "samsung,exynos5250-dw-mshc";
+			compatible = "samsung,exynos3250-dw-mshc";
 			reg = <0x12520000 0x1000>;
 			interrupts = <0 143 0>;
 			clocks = <&cmu CLK_SDMMC1>, <&cmu CLK_SCLK_MMC1>;
-- 
1.9.1

[PATCH 1/2] mmc: dw_mmc: exynos: Add the exynos3250 compatible

[Krzysztof Kozlowski]

On 21.10.2015 15:39, Jaehoon Chung wrote:
> To check more exactly, add the exynos3250 compatible.
> Not use exynos5250 compatibility.

Hi,

I can't find any difference between old and new compatible. Maybe I am
missing something? Maybe there is a difference for these devices?

Anyway if the code is the same then it should use exactly the same
compatible.

Best regards,
Krzysztof

> 
> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
> ---
>  Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt | 2 ++
>  drivers/mmc/host/dw_mmc-exynos.c                         | 7 +++++++
>  2 files changed, 9 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
> index aad9844..cd22ac9 100644
> --- a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
> +++ b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
> @@ -22,6 +22,8 @@ Required Properties:
>  	  specific extensions.
>  	- "samsung,exynos7-dw-mshc-smu": for controllers with Samsung Exynos7
>  	  specific extensions having an SMU.
> +	- "samsung,exynos3250-dw-mshc": for controllers with Samsung Exynos3250
> +	  specific extensions.
>  
>  * samsung,dw-mshc-ciu-div: Specifies the divider value for the card interface
>    unit (ciu) clock. This property is applicable only for Exynos5 SoC's and
> diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
> index 1e75309..1c96218 100644
> --- a/drivers/mmc/host/dw_mmc-exynos.c
> +++ b/drivers/mmc/host/dw_mmc-exynos.c
> @@ -32,6 +32,7 @@ enum dw_mci_exynos_type {
>  	DW_MCI_TYPE_EXYNOS5420_SMU,
>  	DW_MCI_TYPE_EXYNOS7,
>  	DW_MCI_TYPE_EXYNOS7_SMU,
> +	DW_MCI_TYPE_EXYNOS3250,
>  };
>  
>  /* Exynos implementation specific driver private data */
> @@ -73,6 +74,9 @@ static struct dw_mci_exynos_compatible {
>  	}, {
>  		.compatible	= "samsung,exynos7-dw-mshc-smu",
>  		.ctrl_type	= DW_MCI_TYPE_EXYNOS7_SMU,
> +	}, {
> +		.compatible	= "samsung,exynos3250-dw-mshc",
> +		.ctrl_type	= DW_MCI_TYPE_EXYNOS3250,
>  	},
>  };
>  
> @@ -467,6 +471,7 @@ static int dw_mci_exynos_execute_tuning(struct dw_mci_slot *slot)
>  	} while (start_smpl != smpl);
>  
>  	found = dw_mci_exynos_get_best_clksmpl(candiates);
> +
>  	if (found >= 0) {
>  		dw_mci_exynos_set_clksmpl(host, found);
>  		priv->tuned_sample = found;
> @@ -520,6 +525,8 @@ static const struct of_device_id dw_mci_exynos_match[] = {
>  			.data = &exynos_drv_data, },
>  	{ .compatible = "samsung,exynos7-dw-mshc-smu",
>  			.data = &exynos_drv_data, },
> +	{ .compatible = "samsung,exynos3250-dw-mshc",
> +			.data = &exynos_drv_data, },
>  	{},
>  };
>  MODULE_DEVICE_TABLE(of, dw_mci_exynos_match);
> 

[PATCH 1/2] mmc: dw_mmc: exynos: Add the exynos3250 compatible

[Jaehoon Chung]

Hi, Krzysztof.

On 10/22/2015 09:06 AM, Krzysztof Kozlowski wrote:
> On 21.10.2015 15:39, Jaehoon Chung wrote:
>> To check more exactly, add the exynos3250 compatible.
>> Not use exynos5250 compatibility.
> 
> Hi,
> 
> I can't find any difference between old and new compatible. Maybe I am
> missing something? Maybe there is a difference for these devices?

Sorry, I needs to add more explanation about changing compatible.
Exynos3250 has more registers than exynos5250 in dwmmc IP.
Now, we used dwmmc controller with exynos5250 compatible.
Then some codes can't run in dw-mmc.c, if SoC is exynos3250.
For example, there is the checking point in dw_mci_exynos_config_hs400().

static void dw_mci_exynos_config_hs400(struct dw_mci *host, u32 timing)
{
        struct dw_mci_exynos_priv_data *priv = host->priv;
        u32 dqs, strobe;

        /*
         * Not supported to configure register
         * related to HS400
         */
        if (priv->ctrl_type < DW_MCI_TYPE_EXYNOS5420)
                return;

        dqs = priv->saved_dqs_en;
        strobe = priv->saved_strobe_ctrl;

It can't use this feature with exynos5250 compatible.

Does it need to change the compatible from exynos5250 to exynos3250?

Beset Regards,
Jaehoon Chung

> 
> Anyway if the code is the same then it should use exactly the same
> compatible.
> 
> Best regards,
> Krzysztof
> 
>>
>> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
>> ---
>>  Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt | 2 ++
>>  drivers/mmc/host/dw_mmc-exynos.c                         | 7 +++++++
>>  2 files changed, 9 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
>> index aad9844..cd22ac9 100644
>> --- a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
>> +++ b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
>> @@ -22,6 +22,8 @@ Required Properties:
>>  	  specific extensions.
>>  	- "samsung,exynos7-dw-mshc-smu": for controllers with Samsung Exynos7
>>  	  specific extensions having an SMU.
>> +	- "samsung,exynos3250-dw-mshc": for controllers with Samsung Exynos3250
>> +	  specific extensions.
>>  
>>  * samsung,dw-mshc-ciu-div: Specifies the divider value for the card interface
>>    unit (ciu) clock. This property is applicable only for Exynos5 SoC's and
>> diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
>> index 1e75309..1c96218 100644
>> --- a/drivers/mmc/host/dw_mmc-exynos.c
>> +++ b/drivers/mmc/host/dw_mmc-exynos.c
>> @@ -32,6 +32,7 @@ enum dw_mci_exynos_type {
>>  	DW_MCI_TYPE_EXYNOS5420_SMU,
>>  	DW_MCI_TYPE_EXYNOS7,
>>  	DW_MCI_TYPE_EXYNOS7_SMU,
>> +	DW_MCI_TYPE_EXYNOS3250,
>>  };
>>  
>>  /* Exynos implementation specific driver private data */
>> @@ -73,6 +74,9 @@ static struct dw_mci_exynos_compatible {
>>  	}, {
>>  		.compatible	= "samsung,exynos7-dw-mshc-smu",
>>  		.ctrl_type	= DW_MCI_TYPE_EXYNOS7_SMU,
>> +	}, {
>> +		.compatible	= "samsung,exynos3250-dw-mshc",
>> +		.ctrl_type	= DW_MCI_TYPE_EXYNOS3250,
>>  	},
>>  };
>>  
>> @@ -467,6 +471,7 @@ static int dw_mci_exynos_execute_tuning(struct dw_mci_slot *slot)
>>  	} while (start_smpl != smpl);
>>  
>>  	found = dw_mci_exynos_get_best_clksmpl(candiates);
>> +
>>  	if (found >= 0) {
>>  		dw_mci_exynos_set_clksmpl(host, found);
>>  		priv->tuned_sample = found;
>> @@ -520,6 +525,8 @@ static const struct of_device_id dw_mci_exynos_match[] = {
>>  			.data = &exynos_drv_data, },
>>  	{ .compatible = "samsung,exynos7-dw-mshc-smu",
>>  			.data = &exynos_drv_data, },
>> +	{ .compatible = "samsung,exynos3250-dw-mshc",
>> +			.data = &exynos_drv_data, },
>>  	{},
>>  };
>>  MODULE_DEVICE_TABLE(of, dw_mci_exynos_match);
>>
> 
> 

[PATCH 1/2] mmc: dw_mmc: exynos: Add the exynos3250 compatible

[Krzysztof Kozlowski]

On 22.10.2015 11:54, Jaehoon Chung wrote:
> Hi, Krzysztof.
> 
> On 10/22/2015 09:06 AM, Krzysztof Kozlowski wrote:
>> On 21.10.2015 15:39, Jaehoon Chung wrote:
>>> To check more exactly, add the exynos3250 compatible.
>>> Not use exynos5250 compatibility.
>>
>> Hi,
>>
>> I can't find any difference between old and new compatible. Maybe I am
>> missing something? Maybe there is a difference for these devices?
> 
> Sorry, I needs to add more explanation about changing compatible.
> Exynos3250 has more registers than exynos5250 in dwmmc IP.
> Now, we used dwmmc controller with exynos5250 compatible.
> Then some codes can't run in dw-mmc.c, if SoC is exynos3250.
> For example, there is the checking point in dw_mci_exynos_config_hs400().
> 
> static void dw_mci_exynos_config_hs400(struct dw_mci *host, u32 timing)
> {
>         struct dw_mci_exynos_priv_data *priv = host->priv;
>         u32 dqs, strobe;
> 
>         /*
>          * Not supported to configure register
>          * related to HS400
>          */
>         if (priv->ctrl_type < DW_MCI_TYPE_EXYNOS5420)
>                 return;
> 
>         dqs = priv->saved_dqs_en;
>         strobe = priv->saved_strobe_ctrl;
> 
> It can't use this feature with exynos5250 compatible.

Ahh, I see it now. I missed that context and commit message wasn't
explaining this real reason. This real reason - supporting HS400 or
other features not present on Exynos5250 - was not mentioned.

The new compatible make sense now... but I am wondering if instead just
"samsung,exynos5420-dw-mshc" should be used? I think it would give the
same result as your change and if new compatible is not required then it
will be better not to add it.

Best regards,
Krzysztof

> 
> Does it need to change the compatible from exynos5250 to exynos3250?
> 
> Beset Regards,
> Jaehoon Chung
> 
>>
>> Anyway if the code is the same then it should use exactly the same
>> compatible.
>>
>> Best regards,
>> Krzysztof
>>
>>>
>>> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
>>> ---
>>>  Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt | 2 ++
>>>  drivers/mmc/host/dw_mmc-exynos.c                         | 7 +++++++
>>>  2 files changed, 9 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
>>> index aad9844..cd22ac9 100644
>>> --- a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
>>> +++ b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
>>> @@ -22,6 +22,8 @@ Required Properties:
>>>  	  specific extensions.
>>>  	- "samsung,exynos7-dw-mshc-smu": for controllers with Samsung Exynos7
>>>  	  specific extensions having an SMU.
>>> +	- "samsung,exynos3250-dw-mshc": for controllers with Samsung Exynos3250
>>> +	  specific extensions.
>>>  
>>>  * samsung,dw-mshc-ciu-div: Specifies the divider value for the card interface
>>>    unit (ciu) clock. This property is applicable only for Exynos5 SoC's and
>>> diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
>>> index 1e75309..1c96218 100644
>>> --- a/drivers/mmc/host/dw_mmc-exynos.c
>>> +++ b/drivers/mmc/host/dw_mmc-exynos.c
>>> @@ -32,6 +32,7 @@ enum dw_mci_exynos_type {
>>>  	DW_MCI_TYPE_EXYNOS5420_SMU,
>>>  	DW_MCI_TYPE_EXYNOS7,
>>>  	DW_MCI_TYPE_EXYNOS7_SMU,
>>> +	DW_MCI_TYPE_EXYNOS3250,
>>>  };
>>>  
>>>  /* Exynos implementation specific driver private data */
>>> @@ -73,6 +74,9 @@ static struct dw_mci_exynos_compatible {
>>>  	}, {
>>>  		.compatible	= "samsung,exynos7-dw-mshc-smu",
>>>  		.ctrl_type	= DW_MCI_TYPE_EXYNOS7_SMU,
>>> +	}, {
>>> +		.compatible	= "samsung,exynos3250-dw-mshc",
>>> +		.ctrl_type	= DW_MCI_TYPE_EXYNOS3250,
>>>  	},
>>>  };
>>>  
>>> @@ -467,6 +471,7 @@ static int dw_mci_exynos_execute_tuning(struct dw_mci_slot *slot)
>>>  	} while (start_smpl != smpl);
>>>  
>>>  	found = dw_mci_exynos_get_best_clksmpl(candiates);
>>> +
>>>  	if (found >= 0) {
>>>  		dw_mci_exynos_set_clksmpl(host, found);
>>>  		priv->tuned_sample = found;
>>> @@ -520,6 +525,8 @@ static const struct of_device_id dw_mci_exynos_match[] = {
>>>  			.data = &exynos_drv_data, },
>>>  	{ .compatible = "samsung,exynos7-dw-mshc-smu",
>>>  			.data = &exynos_drv_data, },
>>> +	{ .compatible = "samsung,exynos3250-dw-mshc",
>>> +			.data = &exynos_drv_data, },
>>>  	{},
>>>  };
>>>  MODULE_DEVICE_TABLE(of, dw_mci_exynos_match);
>>>
>>
>>
> 
> 

[PATCH 1/2] mmc: dw_mmc: exynos: Add the exynos3250 compatible

[Jaehoon Chung]

On 10/22/2015 12:51 PM, Krzysztof Kozlowski wrote:
> On 22.10.2015 11:54, Jaehoon Chung wrote:
>> Hi, Krzysztof.
>>
>> On 10/22/2015 09:06 AM, Krzysztof Kozlowski wrote:
>>> On 21.10.2015 15:39, Jaehoon Chung wrote:
>>>> To check more exactly, add the exynos3250 compatible.
>>>> Not use exynos5250 compatibility.
>>>
>>> Hi,
>>>
>>> I can't find any difference between old and new compatible. Maybe I am
>>> missing something? Maybe there is a difference for these devices?
>>
>> Sorry, I needs to add more explanation about changing compatible.
>> Exynos3250 has more registers than exynos5250 in dwmmc IP.
>> Now, we used dwmmc controller with exynos5250 compatible.
>> Then some codes can't run in dw-mmc.c, if SoC is exynos3250.
>> For example, there is the checking point in dw_mci_exynos_config_hs400().
>>
>> static void dw_mci_exynos_config_hs400(struct dw_mci *host, u32 timing)
>> {
>>         struct dw_mci_exynos_priv_data *priv = host->priv;
>>         u32 dqs, strobe;
>>
>>         /*
>>          * Not supported to configure register
>>          * related to HS400
>>          */
>>         if (priv->ctrl_type < DW_MCI_TYPE_EXYNOS5420)
>>                 return;
>>
>>         dqs = priv->saved_dqs_en;
>>         strobe = priv->saved_strobe_ctrl;
>>
>> It can't use this feature with exynos5250 compatible.
> 
> Ahh, I see it now. I missed that context and commit message wasn't
> explaining this real reason. This real reason - supporting HS400 or
> other features not present on Exynos5250 - was not mentioned.

Right, it's not enough to explain why needs this patch.

> 
> The new compatible make sense now... but I am wondering if instead just
> "samsung,exynos5420-dw-mshc" should be used? I think it would give the
> same result as your change and if new compatible is not required then it
> will be better not to add it.

I need to check whether it can be used with "samsung,exynos5420-dw-mshc".
If you don't want to add new compatible, then i will check Exynos5420 TRM.
Maybe, i think it can be used with it.

Is it good that use more exact compatible?

Best Regards,
Jaehoon Chung

> 
> Best regards,
> Krzysztof
> 
>>
>> Does it need to change the compatible from exynos5250 to exynos3250?
>>
>> Beset Regards,
>> Jaehoon Chung
>>
>>>
>>> Anyway if the code is the same then it should use exactly the same
>>> compatible.
>>>
>>> Best regards,
>>> Krzysztof
>>>
>>>>
>>>> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
>>>> ---
>>>>  Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt | 2 ++
>>>>  drivers/mmc/host/dw_mmc-exynos.c                         | 7 +++++++
>>>>  2 files changed, 9 insertions(+)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
>>>> index aad9844..cd22ac9 100644
>>>> --- a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
>>>> +++ b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
>>>> @@ -22,6 +22,8 @@ Required Properties:
>>>>  	  specific extensions.
>>>>  	- "samsung,exynos7-dw-mshc-smu": for controllers with Samsung Exynos7
>>>>  	  specific extensions having an SMU.
>>>> +	- "samsung,exynos3250-dw-mshc": for controllers with Samsung Exynos3250
>>>> +	  specific extensions.
>>>>  
>>>>  * samsung,dw-mshc-ciu-div: Specifies the divider value for the card interface
>>>>    unit (ciu) clock. This property is applicable only for Exynos5 SoC's and
>>>> diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
>>>> index 1e75309..1c96218 100644
>>>> --- a/drivers/mmc/host/dw_mmc-exynos.c
>>>> +++ b/drivers/mmc/host/dw_mmc-exynos.c
>>>> @@ -32,6 +32,7 @@ enum dw_mci_exynos_type {
>>>>  	DW_MCI_TYPE_EXYNOS5420_SMU,
>>>>  	DW_MCI_TYPE_EXYNOS7,
>>>>  	DW_MCI_TYPE_EXYNOS7_SMU,
>>>> +	DW_MCI_TYPE_EXYNOS3250,
>>>>  };
>>>>  
>>>>  /* Exynos implementation specific driver private data */
>>>> @@ -73,6 +74,9 @@ static struct dw_mci_exynos_compatible {
>>>>  	}, {
>>>>  		.compatible	= "samsung,exynos7-dw-mshc-smu",
>>>>  		.ctrl_type	= DW_MCI_TYPE_EXYNOS7_SMU,
>>>> +	}, {
>>>> +		.compatible	= "samsung,exynos3250-dw-mshc",
>>>> +		.ctrl_type	= DW_MCI_TYPE_EXYNOS3250,
>>>>  	},
>>>>  };
>>>>  
>>>> @@ -467,6 +471,7 @@ static int dw_mci_exynos_execute_tuning(struct dw_mci_slot *slot)
>>>>  	} while (start_smpl != smpl);
>>>>  
>>>>  	found = dw_mci_exynos_get_best_clksmpl(candiates);
>>>> +
>>>>  	if (found >= 0) {
>>>>  		dw_mci_exynos_set_clksmpl(host, found);
>>>>  		priv->tuned_sample = found;
>>>> @@ -520,6 +525,8 @@ static const struct of_device_id dw_mci_exynos_match[] = {
>>>>  			.data = &exynos_drv_data, },
>>>>  	{ .compatible = "samsung,exynos7-dw-mshc-smu",
>>>>  			.data = &exynos_drv_data, },
>>>> +	{ .compatible = "samsung,exynos3250-dw-mshc",
>>>> +			.data = &exynos_drv_data, },
>>>>  	{},
>>>>  };
>>>>  MODULE_DEVICE_TABLE(of, dw_mci_exynos_match);
>>>>
>>>
>>>
>>
>>
> 
> 

[PATCH 1/2] mmc: dw_mmc: exynos: Add the exynos3250 compatible

[Krzysztof Kozlowski]

On 22.10.2015 14:14, Jaehoon Chung wrote:
> On 10/22/2015 12:51 PM, Krzysztof Kozlowski wrote:
>> On 22.10.2015 11:54, Jaehoon Chung wrote:
>>> Hi, Krzysztof.
>>>
>>> On 10/22/2015 09:06 AM, Krzysztof Kozlowski wrote:
>>>> On 21.10.2015 15:39, Jaehoon Chung wrote:
>>>>> To check more exactly, add the exynos3250 compatible.
>>>>> Not use exynos5250 compatibility.
>>>>
>>>> Hi,
>>>>
>>>> I can't find any difference between old and new compatible. Maybe I am
>>>> missing something? Maybe there is a difference for these devices?
>>>
>>> Sorry, I needs to add more explanation about changing compatible.
>>> Exynos3250 has more registers than exynos5250 in dwmmc IP.
>>> Now, we used dwmmc controller with exynos5250 compatible.
>>> Then some codes can't run in dw-mmc.c, if SoC is exynos3250.
>>> For example, there is the checking point in dw_mci_exynos_config_hs400().
>>>
>>> static void dw_mci_exynos_config_hs400(struct dw_mci *host, u32 timing)
>>> {
>>>         struct dw_mci_exynos_priv_data *priv = host->priv;
>>>         u32 dqs, strobe;
>>>
>>>         /*
>>>          * Not supported to configure register
>>>          * related to HS400
>>>          */
>>>         if (priv->ctrl_type < DW_MCI_TYPE_EXYNOS5420)
>>>                 return;
>>>
>>>         dqs = priv->saved_dqs_en;
>>>         strobe = priv->saved_strobe_ctrl;
>>>
>>> It can't use this feature with exynos5250 compatible.
>>
>> Ahh, I see it now. I missed that context and commit message wasn't
>> explaining this real reason. This real reason - supporting HS400 or
>> other features not present on Exynos5250 - was not mentioned.
> 
> Right, it's not enough to explain why needs this patch.
> 
>>
>> The new compatible make sense now... but I am wondering if instead just
>> "samsung,exynos5420-dw-mshc" should be used? I think it would give the
>> same result as your change and if new compatible is not required then it
>> will be better not to add it.
> 
> I need to check whether it can be used with "samsung,exynos5420-dw-mshc".
> If you don't want to add new compatible, then i will check Exynos5420 TRM.
> Maybe, i think it can be used with it.
> 
> Is it good that use more exact compatible?
>

Actually one thing is the real compatibility of devices and second is
the source code.

Looking at the source code, the behaviour for new exynos3250 compatible
and "samsung,exynos5420-dw-mshc" would be the same, right? This would be
a indication for reusing existing compatible. No need to create new one.

However maybe the devices aren't really compatible and using the same
compatible would prevent adding new features to Exynos5420?

Best regards,
Krzysztof