[HDAudio][ALC285] Native speaker support for HP Spectre x360 15-eb0xxx

[Alexander Giese]

Hello alsa-devel-team,

I have a problem with the built-in speakers on the 2020 model of the 
hp-spectre. From my unexperienced point of view, the audio sinks are 
correctly identified and therefore I tried tweaking the GPIO pins with 
success.

Information from alsa-info is here: 
http://alsa-project.org/db/?f=c8ee13e52fd6b2377573a7123c2887fe4d59c917

When I use hda-verb with the following parameters 2 of 4 of my built-in 
speakers start working:

hda-verb /dev/snd/hwC0D0 0x01 SET_GPIO_DATA 0x02 (or 0x04)
hda-verb /dev/snd/hwC0D0 0x01 SET_GPIO_DIR 0x01
hda-verb /dev/snd/hwC0D0 0x01 SET_GPIO_MASK 0x01

In addition, my mute-mic-led on the keyboard glows when:

hda-verb /dev/snd/hwC0D0 0x01 SET_GPIO_DATA 0x01 (or 0x02)
hda-verb /dev/snd/hwC0D0 0x01 SET_GPIO_DIR 0x04
hda-verb /dev/snd/hwC0D0 0x01 SET_GPIO_MASK 0x04

Since I do not understand how the GPIO-settings are integrated and 
applied in the upstream software for corresponding models, I would very 
much appreciate any help to get this to work out of the box in future 
releases so I do not have tweak my system all the time and others can 
benefit as well.

Any suggestions on getting all 4 speakers to work or the mute-volume-led 
to glow are very much welcome alike!

Thank you very much!

Alexander