[alsa-devel] [PATCH] S3C64XX I2S: Added machine driver for WM8580

Mark Brown broonie at opensource.wolfsonmicro.com
Thu Sep 17 15:11:02 CEST 2009

On Thu, Sep 17, 2009 at 09:26:28PM +0900, jassi brar wrote:

> > > +       /* Currently, WM8580 driver doesn't support PLL-out rates
> > > +        * other than those mentioned in Table-52 Page-58 of WM8580A

> That very manual. And i don't say the WM8580 doesn't support, I said
> the WM8580 driver doesn't support: which can be verified looking at the
> CODEC driver.

Your comment says that only the output frequencies in table 52 are
supported.  Could you please provide more specific references to where
this is done in the driver?  I think you're confusing the fact that the
example table lists most of the common audio frequencies with what the
driver supports here.

> Theoretically all output clocks are possible but usually the PLL coefficients
> have limits on their value and thus final output. WM8580 driver too seems
> to enforce that.
> Though, you wud know better of WM8580.

So what you're actually saying is that 256fs doesn't give us the option
of an an in-range Fvco for the FLL at those frequencies (which is the
check I think you're talking about here)?  That's a limitation of the

Certainly, the comment is not accurate - the contents of table 52 aren't
relevant here, the driver is calculating what it can do dynamically so
the restrictions are a combination of the limits on Fvco and the pre and
post scaling dividers available.

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