On Wed, 2021-01-13 at 15:49 +0100, Takashi Iwai wrote: > On Wed, 13 Jan 2021 15:36:19 +0100, > Bastien Nocera wrote: > > > > Hey, > > > > On Wed, 2020-12-09 at 14:30 +0100, Bastien Nocera wrote: > > > Hey, > > > > > > I've recently bought a SteelSeries Arctis 1 wireless headset: > > > https://steelseries.com/gaming-headsets/arctis-1-wireless-xbox > > > and wanted to write a kernel driver to export a few features of > > > the > > > device, and needed some help getting started. > > > > > > The receiver shows up as a audio class USB device, with extra > > > features > > > on a separate USB interface.[1] > > > > > > The extra features that can be accessed are: > > > - Presence detection. I wanted to use that so PulseAudio or > > > Pipewire > > > could make routing decisions based on whether the headset is > > > available, > > > or probably better, implementing a "jack detection" emulation for > > > the > > > main audio interface? > > > - A slider to change the sidetone volume > > > - Export the battery level > > > > > > The latter is the only one I know how to do, so I'd be happy with > > > any > > > pointers or examples about the first two items. > > > > > > I sent this in December and didn't get any answers, and I would > > appreciate any guidance/examples if you have any into implementing > > this. > > Judging from the link, is it controlled through HID? If so, it's > primarily done by a HID driver, and it doesn't belong to the sound > card stuff, so far. > Though.... > > > I would imagine that the new features would be implemented through > > a > > separate ALSA device with few features, which PulseAudio/Pipewire > > could > > merge with the existing USB audio device. > > ... given that it's implemented in a HID driver, the integration to > the system is a different question. But unless it's implemented as a > sound card device, the rest will become a totally different, > e.g. another PA or PW module. I think that it might be good to have the sidetone configuration implemented as a channel mixer, so it could be shown along with the device volume in sound settings. I believe there's already a device group feature in PulseAudio that could be used to merge the sidetone level with the rest of the USB audio mixers. Is there an example of a mixer like that implemented in a hid or another type of non-ALSA/sound driver?
