Comment 2 for bug 1153276

Node 0x10 [Audio Output] wcaps 0x611: Stereo Digital
  Control: name="IEC958 Playback Con Mask", index=16, device=0
  Control: name="IEC958 Playback Pro Mask", index=16, device=0
  Control: name="IEC958 Playback Default", index=16, device=0
  Control: name="IEC958 Playback Switch", index=16, device=0
  Control: name="IEC958 Default PCM Playback Switch", index=0, device=0
  Device: name="ALC888 Digital", type="SPDIF", device=1
  Converter: stream=8, channel=0
  Digital:
  Digital category: 0x0
  IEC Coding Type: 0x0
  PCM:
    rates [0x5e0]: 44100 48000 88200 96000 192000
    bits [0xe]: 16 20 24
    formats [0x1]: PCM
  Power states: D0 D1 D2 D3 EPSS
  Power: setting=D0, actual=D0

http://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pci/hda/hda_codec.c?id=ea9b43addc4d90ca5b029f47f85ca152320a1e8d

did you upgrade alsa-lib ?

http://git.alsa-project.org/?p=alsa-lib.git;a=commit;h=f5f45589f81c46d4ca4cbbe089441a0f7ac5e197

APLAY

**** List of PLAYBACK Hardware Devices ****
card 0: Intel [HDA Intel], device 0: ALC888 Analog [ALC888 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: Intel [HDA Intel], device 1: ALC888 Digital [ALC888 Digital]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: Intel [HDA Intel], device 3: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0