Comment 6 for bug 1093498

*** List of CAPTURE Hardware Devices ****
card 0: Creative [HDA Creative], device 0: CA0110 Analog [CA0110 Analog]
  Subdevices: 2/2
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1

the previous driver have two capture subdevices

seem line in is the subdevice 0 and Mic is subdevice 1

Node 0x08 [Audio Input] wcaps 0x100103: Stereo Amp-In
  Control: name="Line Capture Volume", index=0, device=0
    ControlAmp: chs=3, dir=In, idx=0, ofs=0
  Device: name="CA0110 Analog", type="Audio", device=0
  Amp-In caps: ofs=0x67, nsteps=0x7f, stepsize=0x01, mute=0
  Amp-In vals: [0x00 0x00]
  Converter: stream=3, channel=0
  SDI-Select: 1
  Connection: 1
     0x10
Node 0x09 [Audio Input] wcaps 0x10010b: Stereo Amp-In
  Control: name="Mic Capture Volume", index=0, device=0
    ControlAmp: chs=3, dir=In, idx=0, ofs=0
  Amp-In caps: ofs=0x67, nsteps=0x7f, stepsize=0x01, mute=0
  Amp-In vals: [0x7c 0x7c]
  Converter: stream=0, channel=0
  SDI-Select: 1
  Connection: 1
     0x11

you need to use latest alsa driver which provide a capture source control for selecting mic or line in

https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/?id=8fadf1da3f370dacbeb4c30fd015a6d2cc47f2fa