Print Page - Is the DMA channel dead?

Title: Is the DMA channel dead?
Post by: fralinux on May 07, 2015, 11:48:48 AM

Hi everyone,
I buy the board IMX233-olinuxino-MAX from Olimex.
I copy the official image from IMX-Olimex Wiki (kernel 2.6.35) into the SD-card for the board.
I don't know how to check the audio line-in of the board!

After an:
[root@alarm ~]# arecord -f cd -D hw:0,0 -d 5 test.wav
Is the DMA channel dead?

Where is the problem?

Fra

Title: Re: Is the DMA channel dead?
Post by: mbergmann on May 07, 2015, 12:00:03 PM

Hi Fra,

there are a bunch of topics regarding iMX233 Audio on this board:

https://www.olimex.com/forum/index.php?topic=3767.0
https://www.olimex.com/forum/index.php?topic=704.0
https://www.olimex.com/forum/index.php?topic=4110.0

Did you read them?

Kind regards

Mike

Title: Re: Is the DMA channel dead?
Post by: fralinux on May 07, 2015, 12:33:38 PM

Hi Mike, thanks for all.

I have read only this, but I have linux kernel 2.6.35:
- https://www.olimex.com/forum/index.php?topic=704.0

Now, I try with the other topics and update you if there is news.
Thanks :)

Fra

Title: Re: Is the DMA channel dead?
Post by: fralinux on May 07, 2015, 12:56:37 PM

Hi Mike,
I have found this topic:
https://www.olimex.com/forum/index.php?topic=3449.0

But no good news :(

Please tell me how to do now?
Fra

Title: Re: Is the DMA channel dead?
Post by: mbergmann on May 07, 2015, 04:03:39 PM

Hi Fra,

I tried with my maxi and an image based on 2.6.35 (2.6.35.3_OLinuXinoR4) and it records by following benbiles instructions from the link you posted above.

Regards

Mike

Title: Re: Is the DMA channel dead?
Post by: fralinux on May 07, 2015, 04:44:40 PM

Hi Mike,

After an:
[root@alarm ~]# arecord -f cd -D hw:0,0 -d 5 test.wav
you have:
"Is the DMA channel dead?"

Tanks,
Fra

Title: Re: Is the DMA channel dead?
Post by: mbergmann on May 07, 2015, 04:48:13 PM

No, I do not have this message.

Btw: have you seen this: https://community.freescale.com/thread/319219

Regards

Mike

Title: Re: Is the DMA channel dead?
Post by: fralinux on May 08, 2015, 02:30:42 PM

Anyway, somebody can help me? :)
In the olinuxino i.mx233, it's possible to use audio codec without any problem? :( :( :(

Best regards.
Fra

Title: Re: Is the DMA channel dead?
Post by: mbergmann on May 08, 2015, 02:52:45 PM

Hi Fra,

the iMX233 is capable doing very descent audio using the build in feature set, which can be seen on the Audio Players using this chip, e.g. SanDisk Sansa Fuze+ or Creative Zen Fi series. They don't use a extra codec and are good players. If you want to have an idea how to program the SoC using bare metal check out the excellent work of Amaury Pouly. He ported RockBox to these iMX233 based players.

As you can see in the different topics on this board there are several problems with the audio implementation of the BSP and I don't think you will get a good Audio quality without putting some effort in it.

Unfortunately I can't say how good the Audio would be if you manage to sort out the current glitches. All I can say is that we had some problems doing a iMX233 HiFi design without external codec. It was a ton of work to eliminate the pops and chirps (the iMX233 seems to be a little 'touch me not'), so we decided to use a Wolfson codec in our second design.

Regards

Mike

Title: Re: Is the DMA channel dead?
Post by: fralinux on May 08, 2015, 03:17:41 PM

Hi Mike,

The Rockbox, is linux based, or pure embedded?

Regard
Fra

Title: Re: Is the DMA channel dead?
Post by: mbergmann on May 08, 2015, 03:21:34 PM

Hi Fra,

RockBox is pure bare metal, no OS involved.

Regards

Mike

Title: Re: Is the DMA channel dead?
Post by: fralinux on May 08, 2015, 03:30:13 PM

Hi Mike,
clear, is pure firmware based, without OS.

Thanks for all.. :)

For manage Wolfson codec, you use SPI or I2C?

Regard,
Fra

Title: Re: Is the DMA channel dead?
Post by: mbergmann on May 08, 2015, 03:36:45 PM

Hi Fra,

Our Codec is connected via SAIF (I2S) for the audio and I2C for the control interface.

Regards

Mike

Title: Re: Is the DMA channel dead?
Post by: fralinux on May 08, 2015, 03:46:16 PM

Hi Mike
okay okay..

thanks,
Fra

Olimex Support Forum

OLinuXino Android / Linux boards and System On Modules => iMX233 => Topic started by: fralinux on May 07, 2015, 11:48:48 AM