[alsa-devel] [PATCH 2/3] ASoC: cs4265: Add native 32bit I2S transport

[Matt Flax]

On 29/08/18 04:56, Mark Brown wrote:
> On Mon, Aug 27, 2018 at 09:28:43AM +0100, Charles Keepax wrote:
>
>> Are you sure this is correct? The datasheet for the part only
>> says it supports up to 24-bit audio and I thought the defines
>> SNDRV_PCM_FMTBIT_S24_LE and U24 are expected to have 32-bits
>> in the slot whilst on the bus.
> No, they're not.  They're expected to be 32 bit in memory and 24 bit on
> the bus.
>

If this is the case, then I would assume that 32bit formats are forced 
through ALSA plughw.

If operation is forced through plughw, then this patch is necessary to 
allow native 32 operation on the bus. The codec drops the 8 LSBs during 
operation as it reads/writes the 24 MSBs.

Matt