Research Pre Audio - Revision history

Playya: add script to strace audiod

2010-03-29T21:17:11Z

add script to strace audiod

StefanSchmidt: add location of audio scripts

2009-11-11T08:20:10Z

add location of audio scripts

StefanSchmidt at 17:48, 21 October 2009

2009-10-21T17:48:04Z

StefanSchmidt: update about audio scripts

2009-10-21T17:24:16Z

update about audio scripts

StefanSchmidt: mention PMIC chip used also for audio

2009-10-13T13:51:15Z

mention PMIC chip used also for audio

StefanSchmidt: start audio research page

2009-10-13T13:43:14Z

start audio research page

New page

This side should cover the audio architecture used on the Palm Pre.

== Soundcards ==

<pre>
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
</pre>

@@ Line 4: / Line 4: @@
 The used TWL4030 PMIC covers the audio part.
 == Soundcards ==
@@ Line 46: / Line 47: @@
 This is also handled by audiod. The scripts can be found in /etc/audio

← Older revision		Revision as of 08:20, 11 November 2009
Line 45:		Line 45:
	</pre>		</pre>

−	This is also handled by audiod. ~~Until now there was no place found where the~~ scripts ~~may~~ be ~~stored~~ in ~~the filesystem. Maybe they are build into audiod.~~	+	This is also handled by audiod. The scripts can be found in /etc/audio

← Older revision		Revision as of 17:48, 21 October 2009
Line 38:		Line 38:

	A good start to dive into this is sound/arm/omap-twl4030/script.c in the kernel patch from palm.		A good start to dive into this is sound/arm/omap-twl4030/script.c in the kernel patch from palm.
		+
		+	New scripts are inserted into the kernel list via:
		+
		+	<pre>
		+	/sys/devices/platform/twl4030_audio/scinit
		+	</pre>
		+
		+	This is also handled by audiod. Until now there was no place found where the scripts may be stored in the filesystem. Maybe they are build into audiod.

← Older revision		Revision as of 17:24, 21 October 2009
Line 16:		Line 16:
	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.

@@ Line 1: / Line 1: @@
 This side should cover the audio architecture used on the Palm Pre.
 == Soundcards ==
 <pre>
 root@castle:/var/home/root# aplay -l