question about ALSA devices not showing up in buildroot build

[Bert Schiettecatte]

Hi all
I am working on getting my ALSA machine driver and codecs working. I
ported over my code which was based on 4.11, and I'm using 5.9.12 at
the moment. At first sight everything seems to be working, but the hw:
, plughw: etc devices are missing and when I list the PCMs with
acrecord -L, I don't see any, even though arecord -l does show the
card. I am using buildroot for my rootfs. So I am wondering if this is
an issue with incorrectly defining the structs in my driver code, or
if this is an issue with missing package in my buildroot config, or if
this is due to a missing configuration file for ALSA in the rootfs.
Previously I was using an off the shelf linaro rootfs when I was still
on kernel version 4.11, and there the PCMs were showing up correctly
and I could see the multiple devices such as hw:, plughw:, dmix: etc.
Thanks!
Bert