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SubjectRe: using mmc2 on panda [was: Regression 3.11-rc1: omap4panda: no usb and consequently no ethernet]
On 10/01/2013 03:19 PM, Balaji T K wrote:
>>>>>> Hi Roger,
>>>>>>
>>>>>> It has been a while, but I would like to pickup this thread. We
>>>>>> have a couple of pandaboards used as test setup. These have an
>>>>>> SDIO adapter hooked up to expansion connector A using MMC2. I have
>>>>>> attached the patch file (just ignore platform_data stuff). Now on
>>>>>> one board it works, but not for the other. I suspect a board issue
>>>>>> so listing the two types that we use:
>>>>>>
>>>>>> PandaBoard rev A2 (dmesg: OMAP4430 ES2.1): works
>>>>>> PandaBoardES rev B1 (dmesg: OMAP4460 ES1.1): nope
>>>>>>
>>>>>> Any hints for me.
>>>>>
>>>>> Does your PandaboardES have the WLAN chip (U4) mounted? If yes, how
>>>>> do you isolate
>>>>> it from your external SDIO adapter?
>>>
>>> On my 4460 board in front of me U4 is not populated, but U3 is (the
>>> TiWi thing).
>>>
>>>>
>>>> OK, just realized that the expansion connector uses different pads
>>>> for MMC2. However, you still
>>>> need to make sure that the other pins (connected to on board WLAN
>>>> chip) are not muxed as MMC2.
>>>
>>> I think Luciano added DT patches for on-board WLAN and it uses MMC5
>>> if I am not mistaken(?). Attached are the dmesg logs of the two boards.
>>
>> Right. WLAN is supposed to use MMC5. But if you don't have Luca's
>> patches, can you please ensure that those pins are muxed either as
>> safe mode
>> or as MMC5? Default seems to be safe mode, but you should cross check.
>>
>> Also in your patches you have set mmc2-clk to PIN_INPUT_PULLUP
>> Shouldn't it be PIN_OUTPUT?
>>
>> Still I have no clue why it works on 4430 and not on 4460. Are you
>> using the same bootloader image on both boards?
>>
> if you are using vaux1, can you check the voltage levels,
>
> From dmesg you attached,
> vaux1 is set to 1.8V on omap4430 and to 2.8V on OMAP4460
>
> 4430
> [ 2.425750] VAUX1_6030: 1000 <--> 3000 mV at 1800 mV
>
> 4460
> [ 2.244262] VAUX1_6030: 1000 <--> 3000 mV at 2800 mV

Nice catch. Not sure whether this is an issue, but worth looking into.

> Can you also check with MMC_DEBUG enabled for any clues.

building....

>> cheers,
>> -roger
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