Hi

Just started to play around with AT91RM9200-Ek dev board from Atmel. The board has an on-board DAC3550a chip for sound. Has anybody got it working for linux and know how and where to find drivers for the kernel?

/Alexander

have you tried the givne linux distribution from ftp://81.80.104.162

linux-2.4.27-vrs1.tar.bz2.

it contains a full support for the board.

Not really. There are no sound driver in that kernel

I did not find a Linux ready to use driver, maybe you found it ?

Anyway I wrote down my own driver, and found this problem:
maybe you already found the solution.

On AT91RM9200-EK I am testing the DAC3550, which is interfaced to ARM9 by means of SSC1.
I follow the guidelines reported in 6020A-ATARM-11/03 "Connecting the ATMEL SSC to an I2S bus"
TF1 and TK1 are regularly generated..
The problem is that TD1 is always low !

However:
1)PDC pointers and counters are regularly updated, just as DMA is regularly working.
2)PDC status signal that Transmit is enabled.
3)If I disable PDC and transmit data writing by software to TDHR, data bits TD1 appear regularly on TD1.

Can somebody solve such problem ?

Some other examples of SSC management ?

Thank you for your attention.

We have a working driver now. I will post it as soon as I have got time to clean it up

The problem you have is that you have to convert you virtual pointers to physical and make sure that the memory is continuous. The pdc is sending a memory that happens to contain zeros at the moment

Hi Alexander

I was just checking to see if you have already posted the driver, if so how can I get hold of it?

Many Thanks.

Jad

I'd like to find out where I can get a copy of the 3550 driver too.

Takk

Hi
Sorry about the delay.

I and a friend developed a very simple driver for the dac3550a chip when we where doing our master thesis in computer science. The driver doesn't support much but it worked with madplay. It was never intended to be used more than experimental . Now we have completed our master thesis and no longer has access to the AT91RM9200-EK dev board but I think I have the latest version laying around here somewhere. I will clean it up a bit and check with the company we did the master thesis for "trade secret" issues. Hopefully i will post the driver tomorrow.

If you want me to be able to verify the driver you could always get me a new evaluation board to play around with . Or even a job would be nice

One problem might be that we used another input chip together in the same driver. This might be a problem but I cant say that it will break the playback

Alexander,

Thanks (in advance) for posting the code you did for your Thesis. Don't worry about cleaning it up.

Also, is it possible to get a copy of your Thesis as well?

Hi

Finaly after a nice vacation I was able to get my hands on the driver . Sorry about the delay

Just go to http://arm.hightech.nu and you will find all the information you need (I hope).

hi
i try to get a squeek out of dac3550a on at91rm9200-ek. i've tried Alexander Saers driver with madplay - without success. it 'plays' but the output is silent.
with setting some weird values to slot_by_frame and bits_by_slot i could get some noise, but with 2/16 it remains perfectly silent, even when i fill at91snd_device->empty with wav_file data from the example.
it looks like i have the same problem as Misha, but even setting at91_ssc1->ssc_thr in loop doesn't help

ok. now it works
here's a patch for Alexander Saers' driver. hope it helps

hi and happy new year
i've updated Alexander Saers code with following functions:
1. support for mono samples
2. support for different bitrates (not heavily tested)
3. basic aumix support (volume, right/left channel balance)

update: to play and mix without hassle create links /dev/dsp and /dev/mixer pointing to /dev/at91snd/0

Hi liftboy,

Could you repost that driver file? Apparently it's a dead link after the forums were 'updated'.

Thanks
Blair

here you are (attention: ugly, buggy code!)