My system has:
$uname -a
Linux rkpi 5.8.11-rockchip64 #20.08.4 SMP PREEMPT Wed Sep 23 17:51:13 CEST 2020 aarch64 aarch64 aarch64 GNU/Linux
Sound stack seems to be loaded, but alsa/pulseaudio sees only hdmi-output device (aplay log below). How to enable analog ouput on 3.5 mm jack?
$sudo aplay -lL
default
Playback/recording through the PulseAudio sound server
null
Discard all samples (playback) or generate zero samples (capture)
samplerate
Rate Converter Plugin Using Samplerate Library
speexrate
Rate Converter Plugin Using Speex Resampler
jack
JACK Audio Connection Kit
oss
Open Sound System
pulse
PulseAudio Sound Server
upmix
Plugin for channel upmix (4,6,8)
vdownmix
Plugin for channel downmix (stereo) with a simple spacialization
sysdefault:CARD=hdmisound
hdmi-sound, ff8a0000.i2s-i2s-hifi i2s-hifi-0
Default Audio Device
dmix:CARD=hdmisound,DEV=0
hdmi-sound, ff8a0000.i2s-i2s-hifi i2s-hifi-0
Direct sample mixing device
dsnoop:CARD=hdmisound,DEV=0
hdmi-sound, ff8a0000.i2s-i2s-hifi i2s-hifi-0
Direct sample snooping device
hw:CARD=hdmisound,DEV=0
hdmi-sound, ff8a0000.i2s-i2s-hifi i2s-hifi-0
Direct hardware device without any conversions
plughw:CARD=hdmisound,DEV=0
hdmi-sound, ff8a0000.i2s-i2s-hifi i2s-hifi-0
Hardware device with all software conversions
usbstream:CARD=hdmisound
hdmi-sound
USB Stream Output
**** List of PLAYBACK Hardware Devices ****
card 0: hdmisound [hdmi-sound], device 0: ff8a0000.i2s-i2s-hifi i2s-hifi-0 [ff8a0000.i2s-i2s-hifi i2s-hifi-0]
Subdevices: 1/1
Subdevice #0: subdevice #0