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

Jaehoon Chung jh80.chung at samsung.com
Fri Nov 28 12:50:36 CET 2014


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 at 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.
> 



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