ALSA
From ArmadeusWiki
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 ->
- http://opensource.wolfsonmicro.com/node/6
- http://www.rpsys.net/openzaurus/patches/alsa/info.html
- http://alsa-project.org/main/index.php/ASoC
nodes creation
in /dev/snd
mknod controlC0 c 116 0 mknod pcmC0D0c c 116 24 mknod pcmC0D0p c 116 16
Installation
- On your Host select ALSA compilation in Linux configuration:
[armadeus]$ 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 --->
- in Buildroot configuration, select the user space packages for ALSA:
[armadeus]$ make menuconfig
Package Selection for the target-> Audio libraries:
--- Audio libraries and applications
[*] alsa-lib
[*] alsa-utils
ALSA utils selection --->
[ ] asterisk
[*] aumix
[ ] libmad
--- libid3tag
--- libmad
[ ] libmad headers in target
[ ] libsndfile
--- libvorbis requires the package libogg to build
[*] madplay
[ ] mpg123
in ALSA utils selection ---> [*] alsaconf [*] alsactl [*] alsamixer [ ] amidi [*] amixer [*] aplay [ ] arecord [ ] iecset [ ] aconnect [ ] aplaymidi [ ] arecordmidi [ ] aseqdump [ ] aseqnet [*] speaker-test
- save your configuration and rebuild your rootfs:
[armadeus]$ make
- after reflashing your rootfs and your Linux kernel on your board, you can load ALSA drivers:
# modprobe spi_imx # modprobe snd-imx-alsa-tsc2102 TI TSC2102 driver initializing audio_dma_request done (8) audio_dma_request done (9) audio support initialized
# lsmod Module Size Used by Not tainted snd_imx_alsa_tsc2102 7204 0 snd_pcm 50760 1 snd_imx_alsa_tsc2102 snd_timer 14084 1 snd_pcm snd_page_alloc 3208 1 snd_pcm snd 28916 3 snd_imx_alsa_tsc2102,snd_pcm,snd_timer soundcore 3332 1 snd tsc2102 10256 1 snd_imx_alsa_tsc2102 hwmon 948 1 tsc2102 spi_imx 9024 0
- if you want OSS support:
modprobe snd-pcm-oss modprobe snd-mixer-oss
- If you want MIDI sequencer support:
modprobe snd-seq modprobe snd-seq-device
Test
- To check if the TSC was detected as a sound chip:
# aplay -lL default:CARD=IMX-ALSA ARMADEUS IMX_ALSA, imx alsa pcm Default Audio Device null Discard all samples (playback) or generate zero samples (capture) **** List of PLAYBACK Hardware Devices **** card 0: IMX-ALSA [ARMADEUS IMX_ALSA], device 0: IMX PCM [imx alsa pcm] Subdevices: 1/1 Subdevice #0: subdevice #0
- To play a test sound:
# 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
