[alsa-devel] Reg: Implementation of GSM digital audio path
Hi all,
Iam working on OMAP3 based custom board. On our board, GSM digital audio path is connected to McBSP3 and TWL4030 digital audio path is connected to McBSP2.
I want to implement a module that transfers GSM audio data and store audio data into some buffer and redirect it to TWL4030 audio codec through McBSP2.
I question is how can I implement this in ASoC?
I studied ASoC framework, but I am unable to understand where to implement my stuff.
Regards, Shariff
On Thursday 25 June 2009 12:47:54 ext shariff wrote:
Hi all,
Iam working on OMAP3 based custom board. On our board, GSM digitalaudio path is connected to McBSP3 and TWL4030 digital audio path is connected to McBSP2.
I want to implement a module that transfers GSM audio data and store audio data into some buffer and redirect it to TWL4030 audio codec through McBSP2.
I question is how can I implement this in ASoC?
I studied ASoC framework, but I am unable to understand where to implement my stuff.
I think the following should do something like that:
arecord -Dplughw:0.0 | aplay -Dplughw:0.1 or arecord -Dhw:0.0 | aplay -Dhw:0.1
I don't know what is the order of the PCMs with the twl4030 codec on your board, this is with the assumption: plughw:0.0 - Voice PCM (McBSP3) plughw:0.1 - Digital audio PCM (McBSP2)
You might want to try the --rate parameter for arecord to use 16KHz recording from the Voice interface..
Regards, Shariff _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
Hi Peter,
Thanks for quick response. I understood some what from your mail.
I will explain, how my hardware is connected.
USB GSM chip -> McBSP3
McBSP2 -> TWL4030
Here, playback functionality will not be there in the GSM path. I need to take audio data from GSM. and redirect this to TWL4030 codec.
The thing is, How and where to implement this GSM path without playback? as I am new to this ASoC framework.
What I understood from ur mail is. Audio is being redirected from the application space i.e arecord will record and store in buffer and this buffer is
being played using aplay to other hardware (twl4030).
Can we handle the same thing in kernel space ( i.e in driver itself).
Regards, Shariff
On Thu, Jun 25, 2009 at 4:05 PM, Peter Ujfalusi peter.ujfalusi@nokia.comwrote:
On Thursday 25 June 2009 12:47:54 ext shariff wrote:
Hi all,
Iam working on OMAP3 based custom board. On our board, GSMdigital
audio path is connected to McBSP3 and TWL4030 digital audio path is connected to McBSP2.
I want to implement a module that transfers GSM audio data and store
audio
data into some buffer and redirect it to TWL4030 audio codec through McBSP2.
I question is how can I implement this in ASoC?
I studied ASoC framework, but I am unable to understand where to
implement
my stuff.
I think the following should do something like that:
arecord -Dplughw:0.0 | aplay -Dplughw:0.1 or arecord -Dhw:0.0 | aplay -Dhw:0.1
I don't know what is the order of the PCMs with the twl4030 codec on your board, this is with the assumption: plughw:0.0 - Voice PCM (McBSP3) plughw:0.1 - Digital audio PCM (McBSP2)
You might want to try the --rate parameter for arecord to use 16KHz recording from the Voice interface..
Regards, Shariff _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
-- Péter
On Thu, Jun 25, 2009 at 03:17:54PM +0530, shariff wrote:
Iam working on OMAP3 based custom board. On our board, GSM digitalaudio path is connected to McBSP3 and TWL4030 digital audio path is connected to McBSP2.
In this scenario your GSM modem is essentially functioning as a CODEC within ASoC. The simplest thing to do is set up a dummy DAI in your machine driver for the GSM modem, register that at startup and then set up a dai_link for that as normal. You can then address the two streams individually as devices on the card.
The OpenMoko is doing something similar with its bluetooth chipset, though that is connected to a second DAI on the CODEC rather than the CPU.
Hi Mark,
Thanks for response.
On my hardware, GSM is connected to McBSP3 not to the TWL4030 CODEC directly. What I have to do is Copy from McBSP3 and redirect this to
McBSP2.
USB GSM chip -> McBSP3
McBSP2 -> TWL4030
I have understood some thing from ur mail. I will study Openmoko ASoC and I will get back to you.
Suggest me wat else I can do?
Regards, Shariff
On Thu, Jun 25, 2009 at 4:11 PM, Mark Brown < broonie@opensource.wolfsonmicro.com> wrote:
On Thu, Jun 25, 2009 at 03:17:54PM +0530, shariff wrote:
Iam working on OMAP3 based custom board. On our board, GSMdigital
audio path is connected to McBSP3 and TWL4030 digital audio path is connected to McBSP2.
In this scenario your GSM modem is essentially functioning as a CODEC within ASoC. The simplest thing to do is set up a dummy DAI in your machine driver for the GSM modem, register that at startup and then set up a dai_link for that as normal. You can then address the two streams individually as devices on the card.
The OpenMoko is doing something similar with its bluetooth chipset, though that is connected to a second DAI on the CODEC rather than the CPU.
participants (3)
-
Mark Brown -
Peter Ujfalusi -
shariff