On Mon, 27 Jun 2022 19:18:54 +0200,
Jan Schär wrote:
>
> The Dell WD15 dock has a headset and a line out port. Add support for
> detecting if a jack is inserted into one of these ports.
> For the headset jack, additionally determine if a mic is present.
>
> The WD15 contains an ALC4020 USB audio controller and ALC3263 audio codec
> from Realtek. It is a UAC 1 device, and UAC 1 does not support jack
> detection. Instead, jack detection works by sending HD Audio commands over
> vendor-type USB messages.
>
> I found out how it works by looking at USB captures on Windows.
> The audio codec is very similar to the one supported by
> sound/soc/codecs/rt298.c / rt298.h, some constant names and the mic
> detection are adapted from there. The realtek_add_jack function is adapted
> from build_connector_control in sound/usb/mixer.c.
>
> I tested this on a WD15 dock with the latest firmware.
>
> Signed-off-by: Jan Schär <jan@xxxxxxxxxx>
> ---
> For testing this patch, you need to change the content of the file
> /usr/share/alsa/ucm2/USB-Audio/Dell-WD15-Dock-HiFi.conf to the following:
> ```
> SectionDevice."Headphones" {
> Comment "Headphones"
>
> Value {
> PlaybackPriority 100
> PlaybackPCM "hw:${CardId}"
> JackControl "Headphone Jack"
>
> If.Headphone_ctl {
> Condition {
> Type ControlExists
> Control "name='Headphone Playback Switch'"
> }
> True {
> PlaybackMixerElem "Headphone"
> PlaybackVolume "Headphone Playback Volume"
> PlaybackSwitch "Headphone Playback Switch"
> }
> }
> }
> }
>
> SectionDevice."Line" {
> Comment "Line Out"
>
> Value {
> PlaybackPriority 200
> PlaybackPCM "hw:${CardId},1"
> JackControl "Line Out Jack"
>
> If.Line_ctl {
> Condition {
> Type ControlExists
> Control "name='Line Playback Switch'"
> }
> True {
> PlaybackMixerElem "Line"
> PlaybackVolume "Line Playback Volume"
> PlaybackSwitch "Line Playback Switch"
> }
> }
> }
> }
>
> SectionDevice."Headset" {
> Comment "Headset Microphone"
>
> Value {
> CapturePriority 100
> CapturePCM "hw:${CardId}"
> JackControl "Headset Mic Jack"
>
> If.Mic_ctl {
> Condition {
> Type ControlExists
> Control "name='Mic Capture Switch'"
> }
> True {
> CaptureMixerElem "Mic"
> CaptureVolume "Mic Capture Volume"
> CaptureSwitch "Mic Capture Switch"
> }
> }
> }
> }
> ```
This is an interesting finding.
Applied both patches to for-next branch now.
Thanks!
Takashi
