WM8978 outputs mono

[sctanf]

Describe the bug

When I2S model is defined as WM8978, the audio output is downmixed to mono.

Preliminary Information

1. Firmware Version: I2S-4MFlash-1716
2. Plugin Version: Music Assistant

Hardware Details

Please describe your hardware setup:

• ESP32 Module: ESP32-PICO-D4
• Board Type: PÚCA DSP
• DAC Chip: WM8978
• Additional Hardware: None

NVS Settings

nvs_config_STR-DG710_1780111032855.json

Logs

N/A

Issue Description

1. Observed Behavior: Stereo audio is rendered in mono
2. Expected Behavior: Stereo audio is rendered in stereo
3. Steps to Reproduce: Configure board with WM8978 and try to play stereo content

Notes

When the WM8978 codec is initialized, it is writing the value 102 to register 49, which is enabling DACR2LMIX and DACL2RMIX. If the value is changed to 6, the codec correctly plays stereo audio.

In the meantime, using default I2S model and manually defining dac_controlset is working.
dac_config: model=I2S,bck=23,ws=25,do=26,mck=0,sda=19,scl=18,i2c=26
dac_controlset: {"init":[{"reg":0,"val":0},{"reg":8,"val":16},{"reg":12,"val":0},{"reg":20,"val":8},{"reg":86,"val":16},{"reg":98,"val":6}],"poweron":[{"reg":2,"val":11},{"reg":5,"val":128},{"reg":6,"val":111}],"poweroff":[{"reg":2,"val":0},{"reg":4,"val":0},{"reg":6,"val":0}]}