PCM list:
hw {
        @args.0 CARD
        @args.1 DEV
        @args.2 SUBDEV
        @args.CARD {
                type string
                default {
                        @func getenv
                        vars {
                                0 ALSA_PCM_CARD
                                1 ALSA_CARD
                        }
                        default {
                                @func refer
                                name 'defaults.pcm.card'
                        }
                }
        }
        @args.DEV {
                type integer
                default {
                        @func igetenv
                        vars {
                                0 ALSA_PCM_DEVICE
                        }
                        default {
                                @func refer
                                name 'defaults.pcm.device'
                        }
                }
        }
        @args.SUBDEV {
                type integer
                default {
                        @func refer
                        name 'defaults.pcm.subdevice'
                }
        }
        type hw
        card $CARD
        device $DEV
        subdevice $SUBDEV
}
plughw {
        @args.0 CARD
        @args.1 DEV
        @args.2 SUBDEV
        @args.CARD {
                type string
                default {
                        @func getenv
                        vars {
                                0 ALSA_PCM_CARD
                                1 ALSA_CARD
                        }
                        default {
                                @func refer
                                name 'defaults.pcm.card'
                        }
                }
        }
        @args.DEV {
                type integer
                default {
                        @func igetenv
                        vars {
                                0 ALSA_PCM_DEVICE
                        }
                        default {
                                @func refer
                                name 'defaults.pcm.device'
                        }
                }
        }
        @args.SUBDEV {
                type integer
                default {
                        @func refer
                        name 'defaults.pcm.subdevice'
                }
        }
        type plug
        slave.pcm {
                type hw
                card $CARD
                device $DEV
                subdevice $SUBDEV
        }
}
plug {
        @args.0 SLAVE
        @args.SLAVE {
                type string
        }
        type plug
        slave.pcm $SLAVE
}
shm {
        @args.0 SOCKET
        @args.1 PCM
        @args.SOCKET {
                type string
        }
        @args.PCM {
                type string
        }
        type shm
        server $SOCKET
        pcm $PCM
}
tee {
        @args.0 SLAVE
        @args.1 FILE
        @args.2 FORMAT
        @args.SLAVE {
                type string
        }
        @args.FILE {
                type string
        }
        @args.FORMAT {
                type string
                default raw
        }
        type file
        slave.pcm $SLAVE
        file $FILE
        format $FORMAT
}
file {
        @args.0 FILE
        @args.1 FORMAT
        @args.FILE {
                type string
        }
        @args.FORMAT {
                type string
                default raw
        }
        type file
        slave.pcm null
        file $FILE
        format $FORMAT
}
null {
        type null
}
cards 'cards.pcm'
front 'cards.pcm.front'
rear 'cards.pcm.rear'
center_lfe 'cards.pcm.center_lfe'
side 'cards.pcm.side'
surround40 'cards.pcm.surround40'
surround41 'cards.pcm.surround41'
surround50 'cards.pcm.surround50'
surround51 'cards.pcm.surround51'
surround71 'cards.pcm.surround71'
iec958 'cards.pcm.iec958'
spdif 'cards.pcm.iec958'
modem 'cards.pcm.modem'
default 'cards.pcm.default'
dmix 'cards.pcm.dmix'
dsnoop 'cards.pcm.dsnoop'
ice1724 {
        type hw
        card 0
}