[U-Boot] [RESEND PATCH v3 1/2] mmc: rockchip_sdhci: add clock init for mmc

[Kever Yang <kever.yang@rock-chips.com>]

Hi Stefan,

     Thanks for your review comment.
On 12/29/2016 02:35 AM, Stefan Herbrechtsmeier wrote:
> Hi,
>
> Am 28.12.2016 um 12:01 schrieb Jaehoon Chung:
>> On 12/28/2016 12:32 PM, Kever Yang wrote:
>>> Init the clock rate to max-frequency from dts with clock driver api.
>>>
>>> Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
>> Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
> This is an incorrect use of the max-frequency property.
>
> The max-frequency value limit the output clock of the mmc interface 
> and depends on the controller, circuit (level shifter), board and so 
> on. It doesn't represents the clock frequency of the controller.
>
> The clock setup inside the clock framework should use the 
> assigned-clock-rates property. The mmc driver should only enable the 
> clock and pass the clock rate together with the max-frequency to the 
> mmc framework.

I'm not good at mmc controller and driver framework, but seems that the 
sdhci core treats the max-frequency as the clock input from clock 
module, right?
What if the mmc controller max-frequency is not equal to the clock 
module output which is possible? Does kernel deal with this, and how.

Thanks,
- Kever
>
> Regards,
>   Stefan
>
>
>
>