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Pulseaudio fails to open SGTL5000 codec in stereo mode resulting in no audio from speaker

PulseAudio fails to open the sgtl5000 card in stereo mode. On the devkit, the speaker is attached to the right line out channel rather than the left (/mono) channel and so there is no sound from PulseAudio.

Jan 07 16:04:32 pureos pulseaudio[2443]: D: [pulseaudio] alsa-mixer.c: Looking at profile output:analog-stereo
Jan 07 16:04:32 pureos pulseaudio[2443]: D: [pulseaudio] alsa-mixer.c: Checking for playback on Analog Stereo (analog-stereo)
Jan 07 16:04:32 pureos pulseaudio[2443]: D: [pulseaudio] alsa-util.c: Trying front:0 with SND_PCM_NO_AUTO_FORMAT ...
Jan 07 16:04:32 pureos pulseaudio[2443]: I: [pulseaudio] (alsa-lib)conf.c: Unknown parameters 0
Jan 07 16:04:32 pureos pulseaudio[2443]: I: [pulseaudio] (alsa-lib)pcm.c: Unknown PCM front:0
Jan 07 16:04:32 pureos pulseaudio[2443]: I: [pulseaudio] alsa-util.c: Error opening PCM device front:0: Invalid argument

There is no "front" PCM device for the sgtl5000 which is what PulseAudio is trying to open:

purism@pureos:~$ aplay -L
null
    Discard all samples (playback) or generate zero samples (capture)
jack
    JACK Audio Connection Kit
pulse
    PulseAudio Sound Server
default:CARD=sgtl5000
    sgtl5000, 
    Default Audio Device
sysdefault:CARD=sgtl5000
    sgtl5000, 
    Default Audio Device
dmix:CARD=sgtl5000,DEV=0
    sgtl5000, 
    Direct sample mixing device
dsnoop:CARD=sgtl5000,DEV=0
    sgtl5000, 
    Direct sample snooping device
hw:CARD=sgtl5000,DEV=0
    sgtl5000, 
    Direct hardware device without any conversions
plughw:CARD=sgtl5000,DEV=0
    sgtl5000, 
    Hardware device with all software conversions
usbstream:CARD=sgtl5000
    sgtl5000
    USB Stream Output
purism@pureos:~$

As I understand it, the "front" device is a standard PCM virtual device created by the default alsalib configuration, in /usr/share/alsa/alsa.conf and /usr/share/alsa/pcm/. I'm not sure yet why it's failing to create the "front" device for the sgtl5000 but presumably there will be something "standard" that's missing from the sgtl5000's driver.