[alsa-devel] at91 SoC Modifications

Paul Kavan pkavan at gmail.com
Thu Jun 21 21:10:54 CEST 2007

If possible, I am more confused now then I was this morning--and that is
after a lot of exploration and probing of the device.

The playback side of everything seems to work well for .raw files. I have
some that I made with my old ssc polling driver. The sound fine using aplay
with either the bare bones or the default alsa.conf file. However, I cannot
use arecord at all. I am not sure why, but something is preventing the sync
line from working during record. The sync line has a .3V,pp square that
rides around 3V DC. The frequency is that of the bit clock ~256.4K. Now,
when I playback a sample, the RF0 and RD0 look like they should.

I have RF0 and TF0 tied together and assume TF0 generates the sync. Also, I
have TK0 and RK0 tied together and assume TK0 generates the clock. Could
this be the problem.

Oh...and playback with PCM A (DSP_A) works fine, but no recording still. I
get the same type of signal on RF0 as before with PCM A fmt. Does anyone
have a sense if this is a ssc configuration problem or an alsa problem?


Paul David Kavan
Project Engineer
GRH Electronics, Inc.
pkavan at gmail.com

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