Hi Boku,
boku wrote on Wednesday, November 16, 2005 8:26 AM:
Dear Martin, Thanks for the information to me. I'd like to ask you further about your audio driver. Did you design the driver based on ALSA architecture? Or you directly write your driver without it? I met some problems while using alsa to build my audio driver for a specific arm soc chip. Thanks in advance.
No, we didn't base on ALSA. We only needed a quick hack to test our audio hardware. For linux audio driver the usage of DMA is a must, to feed the audio codec continuously with data (any interruption in the audio stream would be hearable). Since U-Boot is single-tasking, instead of DMA transfers, a polling mechanism could be used to feed the audio codec continously with data. This is much easier to implement - and is the way we did it.
Regards, Martin
On 8/22/05, Martin Krause Martin.Krause@tqs.de wrote:
Hi,
u-boot-users-admin@lists.sourceforge.net wrote on Monday, August 22, 2005 5:42 AM:
Dear all, I'm searching for some example for audio card driver for U-boot? But it seems most drivers in drivers/ are for ethernet card. Can anyone tell me where I can find it in u-boot? Thanks a lot!~
We implemented some _very_ basic sound commands (play a beep, play square wave, play a microsoft .wav file) to test our hardware with it. Perhaps you will find this usefull. Please look at:
http://source.denx.net/cgi-bin/gitweb.cgi?p=u-boot.git;a=commit;h=6617aae9b9...
The commands are implemented in board/tqm5200/cmd_stk52xx.c