tx2 audio driver

I use tx2 28.1 version,
The sound card played in TX2 is t186ref_mobile_rt565x
, But I can not find tegra_t186f_mobile_rt565x_alt.c in the tegra_alt file
On the contrary only tegra_t210f_mobile_rt565x_alt.c but the music can play
What is the situation here?

No one in the folder about t186ref documents
All t210ref, TX2 now common? still is?

I can’t answer specifically, but there are parts of very early Tegra SoCs being an exact match in architecture on newer SoCs. An example would be that instead of adding more GPIO to one controller to instead make multiple controllers where each controller is the same as the previous generation (though offset in base address). The audio processing engine (APE) is a Cortex A9 and so far as I know is unchanged from the TX1. It is highly likely that the t210 APE code runs the t186 APE. Someone else would need to verify.