ALSA

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This page will summarize the informations to use ALSA on your Armadeus boards.

Introduction

ALSA stands for Advanced Linux Sound Architecture and provides audio and MIDI functionality to the Linux operating system. Everyone wanting to write portable & state of the art Linux applications dealing with sound should consider using ALSA.

ALSA Soc

On the APF boards we are going to use Embedded version of ALSA: ALSA Soc ->

nodes creation

in /dev/snd

mknod controlC0 c 116 0
mknod pcmC0D0c c 116 24
mknod pcmC0D0p c 116 16

Installation

  • Make linux-menuconfig
Device Drivers  ---> Sound  ---> <M> Sound card support 
Device Drivers  ---> Sound  ---> Advanced Linux Sound Architecture  ---> <M> Advanced Linux Sound Architecture
Device Drivers  ---> Sound  ---> Advanced Linux Sound Architecture  --->     ALSA ARM devices  ---> <M> IMX TSC2102 alsa driver
<M> Advanced Linux Sound Architecture
< >   Sequencer support (NEW)
<M>   OSS Mixer API
<M>   OSS PCM (digital audio) API
[*]     OSS PCM (digital audio) API - Include plugin system (NEW)
[ ]   Dynamic device file minor numbers (NEW)
[*]   Support old ALSA API (NEW)
[ ]   Verbose procfs contents (NEW)
[ ]   Verbose printk
[ ]   Debug
[ ]     Debug detection
[ ]     Enable PCM ring buffer overrun/underrun debugging (NEW)
      Generic devices  --->
    ALSA ARM devices  --->
    USB devices  --->
    System on Chip audio support  --->
modprobe soundcore
modprobe snd
modprobe snd-timer
modprobe snd-page-alloc
modprobe snd-pcm
modprobe snd-pcm-oss
modprobe snd-mixer-oss

Only if MIDI sequencer used:

modprobe snd-seq
modprobe snd-seq-device

Specific to DevFull:

modprobe spi_imx
modprobe snd-imx-alsa-tsc2102

Test

Select the user space package for alsa:

# make menuconfig
Package Selection for the target-> Audio libraries -> alsa-lib
# aplay -lL
# aplay -vDhw:0,0 /usr/share/sounds/alsa/Side_Left.wav

Note: the audio file Side_Left.wav can be copied from your host PC

Links