[alsa-devel] Nodes, Widgets, ELD and Digital Surround 5.1 (HDMI) Output?

[bencoxdev at gmail.com]

Hi All,
    I have an Intel HDA compatible device that supports 5.1 digital 
audio output over HDMI. It reports two nodes and two widgets:-

                   Root(0)   
                     |
                    AFG(1)
                    / \
                   /   \
                  /     \
      Audio output(2)    Pin Complex(3)

This setup produces a “Digital Stereo (HDMI) Output” device at user 
level in the operating system.

The codec reports its self  to the operating system as follows 
(from /proc/asound/card0/codec#1)
--------------------------------------------------------------------
AFG Function Id: 0x1 (unsol 1)
No Modem Function Group found
Default PCM:
    rates [0x7f0]: 32000 44100 48000 88200 96000 176400 192000
    bits [0xe]: 16 20 24
    formats [0x1]: PCM
Default Amp-In caps: N/A
Default Amp-Out caps: N/A
GPIO: io=0, o=0, i=0, unsolicited=0, wake=0
--------------------------------------------------------------------
Node 0x02 [Audio Output] wcaps 0x201: Stereo Digital
  Device: name="S3 HDMI 1", type="Audio", device=0
  Converter: stream=0, channel=0
  Digital:
  Digital category: 0x0
--------------------------------------------------------------------
Node 0x03 [Pin Complex] wcaps 0x400381: Stereo Digital
  Pincap 0x00000090: OUT HDMI
  Pin Default 0x185650f0: [Jack] Digital Out at Int HDMI
    Conn = Digital, Color = Red
    DefAssociation = 0xf, Sequence = 0x0
  Pin-ctls: 0x40: OUT
  Unsolicited: tag=00, enabled=0
  Connection: 1
     0x02
--------------------------------------------------------------------

the ELD from the receiving device is:-

monitor_present      1
eld_valid            1
monitor_name         EP-HDMI-RX
connection_type      HDMI
eld_version          [0x2] CEA-861D or below
edid_version         [0x3] CEA-861-B, C or D
manufacture_id       0x1017
product_id           0x901
port_id              0x0
support_hdcp         0
support_ai           1
audio_sync_delay     0
speakers             [0x4f] FL/FR LFE FC RL/RR RLC/RRC

sad_count            2

sad0_coding_type     [0x2] AC-3
sad0_channels        6
sad0_rates           [0xe0] 32000 44100 48000
sad0_max_bitrate     640000

sad1_coding_type     [0x7] DTS
sad1_channels        7
sad1_rates           [0xc0] 44100 48000
sad1_max_bitrate     1536000


Does anyone know what changes would be required to this setup in 
order for the device to be recognised as 
“Digital Surround 5.1 (HDMI) Output” 
by alsa?

TIA
----------------------------------------------------------------------
Regards
Ben