[U-Boot] AT91 working SD with u-boot

[Sebastian Heutling]

Hi Konrad,


On 10/01/2009 10:33 AM, Konrad Mattheis wrote:
> Hi Sebastian,
>
> yes I'm using an AT91SAM9G20-EK Rev.c with two SD slots.
> I used slot a but I think you just have to init slot b.
>
> in PatchV3 you can read:
>
>> at91_mci0_hw_init(int slot, int bus_width)
>
>> switch (slot) {
>> 		case 0:
>> 			.....
>> 		case 1:
> So I think you just have to call at91_mci0_hw_init(1,4) for
> slot b.

No - that is not enough. It just enables the clock for MCI and 
configures the pins. But the MCI itself needs to know which slot to 
address.

Suppose you want to use both slots at the same time (and the drivers 
would support that).
Then you would call:

at91_mci0_hw_init(0, 4)
at91_mci0_hw_init(1, 4)

In order to access both slots the driver (atmel_mci) needs to select 
which slot to address. And that is what the SDCSEL field of MCI-SDCR is 
for (see also Datasheet of the AT91SAM9G20 35.9.4 (probably at page 607)).

Regards

Sebastian