[U-Boot] [PATCH] arm: exynos: fix the div value for set_mmc_clk

[U-Boot] [PATCH] arm: exynos: fix the div value for set_mmc_clk

[Jaehoon Chung]

The most exynos used the  "Ratio + 1" as div value.
And value at register is "Ratio".
So if want to set exact value, it needs to subtract one.

Value at register ("Ratio") = div - 1

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
---
 arch/arm/cpu/armv7/exynos/clock.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm/cpu/armv7/exynos/clock.c b/arch/arm/cpu/armv7/exynos/clock.c
index 4ecce44..6633ffe 100644
--- a/arch/arm/cpu/armv7/exynos/clock.c
+++ b/arch/arm/cpu/armv7/exynos/clock.c
@@ -1654,6 +1654,12 @@ unsigned long get_mmc_clk(int dev_index)
 
 void set_mmc_clk(int dev_index, unsigned int div)
 {
+	/*
+	 * If want to set correct value, it needs to substract one from div.
+	 */
+	if (div > 0)
+		div -= 1;
+
 	if (cpu_is_exynos5()) {
 		if (proid_is_exynos5420() || proid_is_exynos5800())
 			exynos5420_set_mmc_clk(dev_index, div);
-- 
1.9.1

[U-Boot] [PATCH] arm: exynos: fix the div value for set_mmc_clk

[Minkyu Kang]

Hi,

On 20/11/14 17:17, Jaehoon Chung wrote:
> The most exynos used the  "Ratio + 1" as div value.
> And value at register is "Ratio".
> So if want to set exact value, it needs to subtract one.
> 
> Value at register ("Ratio") = div - 1
> 
> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
> ---
>  arch/arm/cpu/armv7/exynos/clock.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/arch/arm/cpu/armv7/exynos/clock.c b/arch/arm/cpu/armv7/exynos/clock.c
> index 4ecce44..6633ffe 100644
> --- a/arch/arm/cpu/armv7/exynos/clock.c
> +++ b/arch/arm/cpu/armv7/exynos/clock.c
> @@ -1654,6 +1654,12 @@ unsigned long get_mmc_clk(int dev_index)
>  
>  void set_mmc_clk(int dev_index, unsigned int div)
>  {
> +	/*
> +	 * If want to set correct value, it needs to substract one from div.
> +	 */

wrong comment style

> +	if (div > 0)
> +		div -= 1;

On trats2 and odroid dts file, div value is set to 0x3.
Then should it modified to 0x4 after applied this patch?

> +
>  	if (cpu_is_exynos5()) {
>  		if (proid_is_exynos5420() || proid_is_exynos5800())
>  			exynos5420_set_mmc_clk(dev_index, div);
> 

Thanks,
Minkyu Kang.

[U-Boot] [PATCH] arm: exynos: fix the div value for set_mmc_clk

[Jaehoon Chung]

Hi,

On 11/24/2014 05:33 PM, Minkyu Kang wrote:
> Hi,
> 
> On 20/11/14 17:17, Jaehoon Chung wrote:
>> The most exynos used the  "Ratio + 1" as div value.
>> And value at register is "Ratio".
>> So if want to set exact value, it needs to subtract one.
>>
>> Value at register ("Ratio") = div - 1
>>
>> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
>> ---
>>  arch/arm/cpu/armv7/exynos/clock.c | 6 ++++++
>>  1 file changed, 6 insertions(+)
>>
>> diff --git a/arch/arm/cpu/armv7/exynos/clock.c b/arch/arm/cpu/armv7/exynos/clock.c
>> index 4ecce44..6633ffe 100644
>> --- a/arch/arm/cpu/armv7/exynos/clock.c
>> +++ b/arch/arm/cpu/armv7/exynos/clock.c
>> @@ -1654,6 +1654,12 @@ unsigned long get_mmc_clk(int dev_index)
>>  
>>  void set_mmc_clk(int dev_index, unsigned int div)
>>  {
>> +	/*
>> +	 * If want to set correct value, it needs to substract one from div.
>> +	 */
> 
> wrong comment style

Will fix.

> 
>> +	if (div > 0)
>> +		div -= 1;
> 
> On trats2 and odroid dts file, div value is set to 0x3.
> Then should it modified to 0x4 after applied this patch?

Those div values are not relevant to cmu.

Best Regards,
Jaehoon Chung

> 
>> +
>>  	if (cpu_is_exynos5()) {
>>  		if (proid_is_exynos5420() || proid_is_exynos5800())
>>  			exynos5420_set_mmc_clk(dev_index, div);
>>
> 
> Thanks,
> Minkyu Kang.
> 

[U-Boot] [PATCH] arm: exynos: fix the div value for set_mmc_clk

[Jaehoon Chung]

The most exynos used the  "Ratio + 1" as div value.
And value at register is "Ratio".
So if want to set exact value, it needs to subtract one.

Value at register ("Ratio") = div - 1

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
---
 arch/arm/cpu/armv7/exynos/clock.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm/cpu/armv7/exynos/clock.c b/arch/arm/cpu/armv7/exynos/clock.c
index b31c13b..3110bb0 100644
--- a/arch/arm/cpu/armv7/exynos/clock.c
+++ b/arch/arm/cpu/armv7/exynos/clock.c
@@ -1656,6 +1656,10 @@ unsigned long get_mmc_clk(int dev_index)
 
 void set_mmc_clk(int dev_index, unsigned int div)
 {
+	/* If want to set correct value, it needs to substract one from div.*/
+	if (div > 0)
+		div -= 1;
+
 	if (cpu_is_exynos5()) {
 		if (proid_is_exynos5420() || proid_is_exynos5800())
 			exynos5420_set_mmc_clk(dev_index, div);
-- 
1.9.1

[U-Boot] [PATCH] arm: exynos: fix the div value for set_mmc_clk

[Minkyu Kang]

On 08/01/15 16:50, Jaehoon Chung wrote:
> The most exynos used the  "Ratio + 1" as div value.
> And value at register is "Ratio".
> So if want to set exact value, it needs to subtract one.
> 
> Value at register ("Ratio") = div - 1
> 
> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
> ---
>  arch/arm/cpu/armv7/exynos/clock.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/arch/arm/cpu/armv7/exynos/clock.c b/arch/arm/cpu/armv7/exynos/clock.c
> index b31c13b..3110bb0 100644
> --- a/arch/arm/cpu/armv7/exynos/clock.c
> +++ b/arch/arm/cpu/armv7/exynos/clock.c
> @@ -1656,6 +1656,10 @@ unsigned long get_mmc_clk(int dev_index)
>  
>  void set_mmc_clk(int dev_index, unsigned int div)
>  {
> +	/* If want to set correct value, it needs to substract one from div.*/
> +	if (div > 0)
> +		div -= 1;
> +
>  	if (cpu_is_exynos5()) {
>  		if (proid_is_exynos5420() || proid_is_exynos5800())
>  			exynos5420_set_mmc_clk(dev_index, div);
> 

applied to u-boot-samsung.

Thank,
Minkyu Kang.