[U-Boot] [PATCHv5 09/14] mmc: support the DDR mode for eMMC

[Jaehoon Chung]

On 05/21/2014 08:52 PM, Hector Palacios wrote:
> On 05/21/2014 04:20 AM, Jaehoon Chung wrote:
>> Hi, Hector.
>>
>> On 05/21/2014 01:37 AM, Hector Palacios wrote:
>>> Hi,
>>>
>>> On 05/16/2014 06:59 AM, Jaehoon Chung wrote:
>>>> Signed-off-by: Jaehoon Chung <jh80.chung at samsung.com>
>>>> Tested-by: Lukasz Majewski <l.majewski at samsung.com>
>>>> Acked-by: Lukasz Majewski <l.majewski at samsung.com>
>>>
>>> What platforms did you test DDR mode on?
>>
>> I have tested DDR mode with exynos board.
>>
>>> I tried this on an Freescale i.MX6 based platform but the driver returned error code COM_ERR (-18) when trying to switch to any of the DDR modes. I guess the fsl_esdhc.c driver needs some adaptation for DDR to work.
>>
>> I didn't know how work DDR mode at fsl_esdhc.c.(If you share the host controller TRM, it's helpful to me.)
>> Host controller also need to change the DDR mode.
>>
>> I wonder your board didn't work not to enable the DDR mode?
> 
> Thank you, yes the fsl_esdhc.c driver does not yet support enabling of DDR mode.
> I think it should be easy to implement, I believe it is just a question of changing the clock frequency.
I need to change the clock frequency, too.
I guess that if controller support the DDR mode, there is a register relevant to DDR mode.

Best Regards,
Jaehoon Chung
> 
> Best regards,
> -- 
> Hector Palacios
>