[U-Boot] mmc: sdhci: Add a quirk to add delay during completion of sdhci_send_cmd

[Jaehoon Chung]

On 04/09/2013 06:41 PM, Jagan Teki wrote:
> Hi Tushar,
> 
> On Mon, Apr 8, 2013 at 9:22 AM, Tushar Behera <tushar.behera at linaro.org> wrote:
>> On 04/07/2013 10:27 AM, Jagan Teki wrote:
>>> Hi,
>>>
>>> I saw that you have been added the SDHCI_QUIRK_WAIT_SEND_CMD on below commit
>>> http://git.denx.de/?p=u-boot.git;a=commitdiff;h=13243f2eafc4292917178051fe1bb5aab2774dca
>>>
>>> I need few quires regarding the QUIRK delay.
>>> 1. Why the delay is 1000
>>> +       if (host->quirks & SDHCI_QUIRK_WAIT_SEND_CMD)
>>> +               udelay(1000);
>>> +
>>> 2. is this delay specific to s5p_sdhci  controller?
>>
> 
> BTW:
> Can you please help me out what is the reason for max and min clocks
> are at 52000000 and 400000 respectively.
> 
> As per my knowledge the max clock of sdhci on spec-2 is 50000000
> (50Mhz), I may be in correct.
Right..But eMMC can use up to 52MHz.
And see into the drivers/mmc/mmc.c..SD-card's max_dtr is set to 50MHz, if card is supported HS_MODE.
> 
> Request for your help.
> 
> Thanks,
> Jagan.
> 
>> This was specific to s5p_sdhci driver so as to replicate the behavior of
>> s5p_mmc driver.
>>
>>> 3. I have an issue "Controller never released inhibit bit(s)"
>>>    but when I enable this quirk on my driver with udelay(10000), it's
>>> working.
>>
>> I am not sure about the exact delay as per the spec. I have added
>> Jaehoon to CC who might have additional information about this.
>>
>>>
>>> Could you please help me.
>>>
>>> Thanks,
>>> Jagan.
>>>
>>
>>
>> --
>> Tushar Behera
>