[alsa-devel] alsa on Atmel at91

Liam Girdwood lg at opensource.wolfsonmicro.com
Tue Apr 17 18:36:22 CEST 2007

On Tue, 2007-04-17 at 17:57 +0200, Michel Benoit wrote:
> Thanks.  I got the code, included all the ASoc stuff in my local tree
> and rebuilt the kernel.    If i understand the docs correctly I have
> to write a codec driver for my audio chip and some machine code to set
> up the particulars for my board (clocks, io pins etc.).

Your correct, you will need a codec driver and a machine driver to glue
the codec to the AT91 SSC and do any machine specific config.

Fwiw, all the development is done here on the dev branch:-


> Am I missing something?
> The codec we use has no control functions (no i2c/spi comm) it simply
> plays back the samples it reads on the i2s bus.  This should thus
> translate to a simple codec driver. Is there a codec driver that uses
> i2s on the at91 that I can use as a base for my driver?

Frank has written a codec driver for a dumb BT codec (attached and link
below). This could be renamed and with a little string changes could be
used as a generic dumb codec driver.


> I haven't really understood yet how to include the machine code.
> Should this be done in the same way as the other platform drivers in
> arch/arm/mach-at91rm9200/board-xxx.c? Is there some sample code that I
> can use as a model?

I would use the eti_b1_wm8731.c as an example machine driver for your
board. You will need to replace any WM8731 references and add your
boards own specific clocks, gpio's etc. 


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