[alsa-devel] [PATCH 2/3] ASoC: omap-mcbsp: change the DSP_B mode to DSP_A mode
peter.ujfalusi at nokia.com
Thu Apr 9 12:16:55 CEST 2009
On Thursday 09 April 2009 13:00:14 Nikula Jarkko (Nokia-D/Helsinki) wrote:
> On Thu, 9 Apr 2009 11:34:41 +0200
> "Ujfalusi Peter (Nokia-D/Tampere)" <peter.ujfalusi at nokia.com> wrote:
> > - case SND_SOC_DAIFMT_DSP_B:
> > + case SND_SOC_DAIFMT_DSP_A:
> > /* 0-bit data delay */
> > regs->rcr2 |= RDATDLY(0);
> > regs->xcr2 |= XDATDLY(0);
> > --
> Are you absolutely sure on this? According to WM9713, it's the DSP_A
> where MSB is valid after 1 bit clock period of the FS.
I think this is correct. The data is going to be valid exactly the same way,
as the WM9713 data sheet describes.
As for the DSP_B mode: I think it can be implemented like this:
Invert the frame sync polarity, Then:
regs->srgr2 |= FPER(wlen * channels - 1);
regs->srgr1 |= FWID(0); /* FS pulse width is 1 */
So the MSB will be in the correct place.
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