[alsa-devel] ASoC and a codec that can't be controlled

Liam Girdwood lg at opensource.wolfsonmicro.com
Tue May 29 10:53:10 CEST 2007


On Mon, 2007-05-28 at 19:18 -0500, Timur Tabi wrote:
> Liam Girdwood wrote:
> 
> > Yes, although my feeling is that a codec "driver" would still be needed
> > to define the capabilities of your codec within the audio subsystem.
> > 
> > e.g. supported sample rates, interface formats, etc
> 
> I'm curious - why would the codec driver dictate all that?  On my board, the sample rates are determined by the I2S controller, not the codec, because in order to change the sample rate, I program new divisors into the I2S controller's registers.


Some codecs can only support a small range of sample rates e.g. 8k &
48k, whilst your controller may support more. This just makes sure the
audio is set a rate the codec can handle, otherwise audio quality will
probably suffer.

Liam



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