CMPCI(4)

CMPCI(4) | Kernel Interfaces Manual | CMPCI(4)

# NAME

cmpci — C-Media CMI8x38 audio device driver

# SYNOPSIS

cmpci* at pci? dev ? function ?
audio* at audiobus?
mpu* at cmpci?
opl* at cmpci? flags 1

# DESCRIPTION

The cmpci device driver supports C-Media CMI8x38 based sound cards.

The device has SPDIF input/output interfaces, 16bit CODEC with analog mixer, OPL3 FM Synthesizer, and MPU401 compatible MIDI I/O port interface.

# MIXER DEVICE

The mixer device of cmpci driver can be accessed via mixerctl(1) command. The complex structure is analyzed as follows.

    SPDIF in  ----------------------
    #1(coax)->|spdin1              |  R    -----------------------
    #2(opt)-->|spdin2  spdif.input |--*->--|spdin   spdif.output |--> SPDIF
           -->|spdout              |  | -->|playback             |    output
           |  ----------------------  | |  -----------------------
           --------------------<------+-*
         ---------<-------------------+-+----------------------------------
         |  ------------------------  | |   -----------------------       |
         -->|legacy  spdif.output. |--+-*-->|spdout               |       |
         -->|wave    playback      |  ----->|spdin  spdif.monitor |----   |
         |  ------------------------     NC-|off                  |   |   |
         ---------<-- spdif                 -----------------------   |   |
             -------+------- dac ------------    -----------------    v   |
    wave  -->|playback.mode|---->|inputs.dac|-*->|inputs.dac.mute|->----- |
    playback ---------------     ------------ R  -----------------  | + | |
                      -----------------     ---------------------   |mix| |
    FM synthesizer -->|inputs.fmsynth |--*->|inputs.fmsynth.mute|-->----- |
                      -----------------  R  ---------------------     *->--
    CD        ----------------------   ---------------------------    v
    LINE-IN ->|inputs.{cd,line,aux}|-*>|inputs.{cd,line,aux}.mute|->-----
    AUX       ---------------------- R ---------------------------  |   |
              ------------------                                    |   |
    PC-SPK -->| inputs.speaker |----------------------------------->| + |
              ------------------                                    |   |
              -------------------  ------------  -----------------  |mix|
    MIC --*-->|inputs.mic.preamp|->|inputs.mic|->|inputs.mic.mute|->|   |
          |   -------------------  ------------  -----------------  -----
          |   ------------   -----------------                       |
          --->|record.mic|-->|               |                       v
              ------------   | record.source |-->to         -----------
                        *R-->| (select, mix) |   recording  |outputs.*|-->
                             -----------------              ----------- SPK
                                                                     (front)

Note the 2nd SPDIF input exists only on CMI8738/PCI-6ch versions.

# MIXER EXAMPLES

Here are examples about wave playback and SPDIF input/output ports.

Playback to speaker, SPDIF input to SPDIF output

  > `mixerctl -w playback.mode=dac spdif.output=spdin spdif.monitor=off`

Playback to SPDIF output, SPDIF input to speaker

  > `mixerctl -w playback.mode=spdif spdif.output=playback spdif.output.playback=wave spdif.monitor=spdin`

SPDIF input to both SPDIF output and speaker

  > `mixerctl -w spdif.output=spdin spdif.monitor=spdin`

Playback to both SPDIF output and speaker

  > `mixerctl -w playback.mode=spdif spdif.output=playback spdif.output.playback=wave spdif.monitor=spdout`

Mix playback and SPDIF input to speaker

  > `mixerctl -w playback.mode=dac spdif.monitor=spdin`

# SEE ALSO

mixerctl(1), audio(4), midi(4), mpu(4), opl(4), pci(4)

# HISTORY

The cmpci device driver appeared in NetBSD 1.5.

# BUGS

4ch/6ch playback is not yet available. Joystick port is not supported.

spdif.output.playback=legacy does not seem to work properly.

June 22, 2005 | NetBSD 7.0