[alsa-devel] [PATCH 4/7] ASoC: Fix Zylonite voice interface stereo configurations

Daniel Mack daniel at caiaq.de
Thu Feb 26 11:03:14 CET 2009


On Thu, Feb 26, 2009 at 10:59:16AM +0100, pHilipp Zabel wrote:
> >> The particular problem with the PXA SSP mode is that I've not yet seen a
> >> configuration (neighter in slave nor in master mode) where it sends out
> >> 16 bits of left channel information, followed by 16 bits of zeros, then
> >> 16 bits of right channel and finally another 16bits of zeros (which
> >> exactly what they talk about in the 'i2s via ssp' application note).
> >> Has anyone ever got that?
> >
> > Not to my knowledge.
> 
> I think I've tried to do this by setting network mode with four slots
> à 16 bit data width, with a SFRMWDTH of 32 and only the first and
> third slot active (SSTSA[TTSA] = 0x5). During the inactive slots,
> SSPTXD should be forced low, as long as SSPSP[ETDS] is not set.
> It didn't work out, but I'm not sure whether I've set up everything
> correctly.

This is exactly how I understand the docs as well, so thanks for sharing
this :)

> My whole understanding of this SSP busineess is rather cloudy.

To me too, especially because the documents are faulty.

> Is that 'i2s via ssp' application note downloadable somewhere?

Only if you signed an NDA with Marvell :-/

Daniel



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