Re: [PATCH v3 6/6] ASoC: qdsp6: dt-bindings: Add q6afe pcm dt binding documentation

From: Srinivas Kandagatla
Date: Wed Feb 12 2020 - 06:43:46 EST




On 12/02/2020 11:01, Adam Serbinski wrote:

+
+ - qcom,pcm-slot-mapping
+ÂÂÂ Usage: required for pcm interface

Are these not specific to 8k and 16k mode ?
We should probably list values for both modes here.

No, this is just the offset that the audio sample is placed in with respect to a maximum of 4 slots, 16 bits wide, beginning with the sync pulse.


That's not true atleast by the QDSP documentation,
according to it we will use more slots to transfer at higher sample rate. ex:
16 kHz data can be transferred using 8 kHz samples in two
slots.

Also there are 32 slots for each of 4 supported channels for PCM AFE port.



When switching between 8 and 16k sample rate, it is just the sync pulse rate that is changed. The audio sample will be delivered in the same slot, just at a different frequency.