If you bought a Sound­Blaster Live! 24 bit and you wanted to use its AUX input under linux then you prob­a­bly noticed that alsa’s driver (ca0106) doesn’t pro­vide such func­tion­al­ity.
Adding it is not a real issue, prat­i­cally the card has three inputs:

  1. microphone
  2. line in
  3. input

Those inputs are mutu­ally exclu­sive since they uses the same chan­nel. Prat­i­cally talk­ing this mean that they cannot oper­ate simul­ta­ne­ously, and making the AUX work­ing is just a matter of enabling/disabling the pipe against its controller.

Here there is a patch against linux kernel vanilla 2.6.16-rc1. The only issue I found is that if anyone uses the AUX, there’s some back­ground noise but I’m still trying to fig­ur­ing out if this issue comes from the TV card that’s attached to or from the patch itself.

Please note that this patch needs test­ing: if you can test it let me know both if every­thing goes ok and if some­thing goes wrong.