Re: [PATCH 2/2] ASoc: wm8731: add normal mode with 12MHz XTAL

[Charles Keepax <ckeepax@opensource.wolfsonmicro.com>]

On Sun, Jun 19, 2016 at 05:46:02PM -0400, Rob Calhoun wrote:
> Hi Matt,
> 
> Based on my experience with the WM8737, the bitclock will always run
> at 12 MHz on these devices in USB mode. While the carrying capacity of
> the channel is always 12 Mbps, the data put on the wire by the codec
> depend on the sample rate, number of channels, and bit depth. This
> leaves some unused capacity in the channel. It is the responsibility
> of the receiving digital audio interface to pull off the appropriate
> number of bits every time the LRCLK/frameclock fires and ignore the
> rest of it. For example in I2S mode, 2-channel, 32-bit, the DAI should
> pull off the first 32 bits following each LRCLK transition.

Thanks very much for adding this, sounds like this is basically
how the part operates then. Although I feel the datasheet could
have been more clear, apologies for that.

Thanks,
Charles