Re: AM335x BeagleBone SPI Issues

[Jack Mitchell <ml@communistcode.co.uk>]

On 04/01/13 16:21, Jack Mitchell wrote:
> On 04/01/13 14:46, Jan Lübbe wrote:
>> Hi,
>>
>> On Tue, 2012-12-11 at 17:02 +0000, Jack Mitchell wrote:
>>> On 11/12/12 16:24, Jack Mitchell wrote:
>>>> On 11/12/12 15:22, Ben Gamari wrote:
>>>>> Jack Mitchell <ml@communistcode.co.uk> writes:
>>>>>> Thank you, the reordering dma patch fixed the dma issue I was 
>>>>>> having!
>>>>>> However, the bad news, I now get the same results for the dma and
>>>>>> non-dma spidev test. While the scope shows the SPI clk and data is
>>>>>> fine,
>>>>>> the reading from the program still shows 0x00 for all words.
>>>>>>
>>>>> Just to make sure this has been thought of: I've seen this sort of
>>>>> behavior in the past when the CLK pin wasn't configured as an input.
>> *snip*
>>
>>> My bad! The jumper bridge had come loose, it works now! Yippee!
>>>
>>> root@beaglebone:~# ./spidev -D /dev/spidev2.0
>>> spi mode: 0
>>> bits per word: 16
>>> max speed: 24000000 Hz (24000 KHz)
>>>
>>> FF FF FF FF FF FF
>>> 40 00 00 00 00 95
>>> FF FF FF FF FF FF
>>> FF FF FF FF FF FF
>>> FF FF FF FF FF FF
>>> DE AD BE EF BA AD
>>> F0 0D
>>> root@beaglebone:~#
>>>
>>> Thanks everyone, and do I need to submit any patches to clear this 
>>> all up?
>>>
>>> Currently all I see is changing the clk pins from output to input (if
>>> this is a valid change?).
>> I just stumbled over the same problem and have not seen any patch for
>> this fix. Have I missed something or should I send a patch? Which would
>> be the correct base for such a patch?
>>
>> Regards,
>> Jan
>
> I didn't submit a patch for this but easily could. I was confused 
> about what tree to base it against as at the time (may still be the 
> same) DT SPI for AM335x was not in a mainline tree. I hoped someone 
> would pick it up when posting DT SPI for mainline....
>

I've just had confirmation from Matt Porter on IRC that this change will 
be present in the next iteration of his DMA Engine series, which I 
believe brings in the DT SPI support.

Cheers All,
Jack

-- 

   Jack Mitchell (jack@embed.me.uk)
   Embedded Systems Engineer
   http://www.embed.me.uk

--

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