Difference between revisions of "Research Pre Audio"
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(mention PMIC chip used also for audio) |
(update about audio scripts) |
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Subdevice #0: subdevice #0 | Subdevice #0: subdevice #0 | ||
</pre> | </pre> | ||
| + | |||
| + | == Scripts == | ||
| + | |||
| + | Palm uses scripts to configure the lower levels of the sound system that are executed inside the kernel. Audiod triggers them over a sysfs interface. | ||
| + | <pre> | ||
| + | echo "#list" > /sys/devices/platform/twl4030_audio/scdebug | ||
| + | </pre> | ||
| + | for example lists you all available scripts over the kernel message output which you can view with dmesg. You can also try | ||
| + | |||
| + | <pre> | ||
| + | #all | ||
| + | #volume | ||
| + | #init | ||
| + | </pre> | ||
| + | |||
| + | These scripts can be triggered by writing is name as a string into | ||
| + | |||
| + | <pre> | ||
| + | /sys/devices/platform/twl4030_audio/scrun | ||
| + | </pre> | ||
| + | |||
| + | A good start to dive into this is sound/arm/omap-twl4030/script.c in the kernel patch from palm. | ||
Revision as of 18:24, 21 October 2009
This side should cover the audio architecture used on the Palm Pre.
Hardware
The used TWL4030 PMIC covers the audio part.
Soundcards
root@castle:/var/home/root# aplay -l **** List of PLAYBACK Hardware Devices **** card 0: mcbsp2 [twl4030-i2s (mcbsp2)], device 0: omap-mcbsp-pcm [omap-mcbsp-pcm] Subdevices: 1/1 Subdevice #0: subdevice #0 card 1: mcbsp3 [btsco (mcbsp3)], device 0: omap-mcbsp-pcm [omap-mcbsp-pcm] Subdevices: 1/1 Subdevice #0: subdevice #0
Scripts
Palm uses scripts to configure the lower levels of the sound system that are executed inside the kernel. Audiod triggers them over a sysfs interface.
echo "#list" > /sys/devices/platform/twl4030_audio/scdebug
for example lists you all available scripts over the kernel message output which you can view with dmesg. You can also try
#all #volume #init
These scripts can be triggered by writing is name as a string into
/sys/devices/platform/twl4030_audio/scrun
A good start to dive into this is sound/arm/omap-twl4030/script.c in the kernel patch from palm.