Requirement for at91-sama5d2_adc timestamp buffer

[<Eugen.Hristev@microchip.com>]

Hello Jonathan,

I found an issue with at91-sama5d2_adc driver, namely, when using DMA 
and timestamp in the same time, the hardware provides the sample in the 
fashion (2 bytes per channel) * (number of channels) - as copied by the 
DMA master to memory.
I compute a software timestamp , and then push to buffers with timestamp.
However your push code will try to write this timestamp inside my buffer 
! and overwrite my samples... I have multiple samples in the buffer 
(watermark number) and there is no space between them because the 
hardware copies the conversion data directly in this buffer.

Do you have any suggestion on how to solve this, except 1) giving up the 
timestamp in this mode or 2) copy to another buffer with more space for 
timestamp storage ?

Thanks,
Eugen