[alsa-devel] driver mixer control questions

[Tim Harvey]

I'm troubleshooting an issue with an ALSA driver I wrote for a very unique
hardware platform.  In this case I have an audio codec which only has a usable
'line-in' capture source.  Currently the only mixer control I've created is a
'Master Playback Volume'.  Do I need to create some kind of control for
'line-in'?  

I'm unclear how to 'register' capture inputs so that they will be returned by
the OSS mixer emulation's ioctl SOUND_MIXER_READ_RECMASK.  Currently that ioctl
returns 0 for my mixer device.

Also, is a control 'switch' such as 'Master Playback Switch' simply a mute
control or is it intended to be any type of control which could have enumerated
values?

Thanks,

Tim