[U-Boot] [PATCH 1/2] FSL/eSDHC: enable the peripheral clock to detect the card

[Stefano Babic <sbabic@denx.de>]

On 27/03/2012 13:01, Dirk Behme wrote:
> On 27.03.2012 12:25, Chang-Ming.Huang at freescale.com wrote:
>> From: Jerry Huang <Chang-Ming.Huang@freescale.com>
>>
>> According to the card detection of p1/p2 paltform RM,
> 
> typo => platform
> 
>> we should set SYSCTL[PEREN] to enable the clock.
>> Otherwise, after booting the u-boot, and then inserting the SD card,
>> the SD card can't be detected.
>>
>> Signed-off-by: Jerry Huang <Chang-Ming.Huang@freescale.com>
>> CC: Andy Fleming <afleming@gmail.com>
>> ---
>>  drivers/mmc/fsl_esdhc.c |    2 ++
>>  1 files changed, 2 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c
>> index a2f35e3..1682a79 100644
>> --- a/drivers/mmc/fsl_esdhc.c
>> +++ b/drivers/mmc/fsl_esdhc.c
>> @@ -491,6 +491,8 @@ int fsl_esdhc_initialize(bd_t *bis, struct
>> fsl_esdhc_cfg *cfg)
>>      /* First reset the eSDHC controller */
>>      esdhc_reset(regs);
>>  
>> +    esdhc_write32(&regs->sysctl, SYSCTL_PEREN);
> 
> If I read the iMX6 manual correctly, the SYSCTL_PEREN isn't implemented
> there. 

In the copy I could put my hands, SYSCTL_PEREN is implemented for i.MX6.
However, I do not know if this has an influence. ESDHC should be clocked
with SDCLKEN, that is enabled by default on i.MX (both MX5 and MX6).

> So this should be a NOP for iMX6?

However, if it is not implemented and it is marked as reserved, we
should not set it.

Best regards,
Stefano Babic

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