From: Maxime Ripard <maxime.ripard@bootlin.com>
To: alsa-devel@alsa-project.org
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>,
Takashi Iwai <tiwai@suse.com>,
Liam Girdwood <lgirdwood@gmail.com>, Chen-Yu Tsai <wens@csie.org>,
Mark Brown <broonie@kernel.org>,
Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
Jaroslav Kysela <perex@perex.cz>,
linux-arm-kernel@lists.infradead.org
Subject: Best representation for TDM devices
Date: Thu, 25 Jul 2019 15:01:12 +0200 [thread overview]
Message-ID: <20190725130112.3j2vi4dyngyr6yh3@flea> (raw)
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Hi,
I'm currently working on a device that has two Analog's ADAU7002
connected to an I2S/TDM Controller (sound/soc/sunxi/sun4i-i2s.c, with
some modifications), over the slots 1/2 and 3/4.
The capture itself is working fine, however I'm not quite sure about
the way to expose those streams to the userspace.
Since I have two codecs, I have two links (described through
simple-card) and thus two subdevices. However, the microphones
connected are really separate streams, so ideally (I guess?) we should
have 1 subdevice per microphone.
An alternative would be that we capture the whole 4 channels and use
dsnoop to demux them, but trying to use the device directly (using
arecord -D hw:0) results in the ioctl to change the number of channels
being rejected, I'm assuming because each codec only has 2 channels?
So I'm a bit lost at this point about how I should go and expose
this. I couldn't really find any similar setup either in the
kernel. Any preferred way of doing this?
Thanks!
Maxime
--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
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next reply other threads:[~2019-07-25 13:01 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-25 13:01 Maxime Ripard [this message]
2019-07-25 17:44 ` Best representation for TDM devices Mark Brown
[not found] <CAMTEBE0mPY=44txPC2G+Cb=NqeH6Cqesar9Vkq0afXBv4dUWHQ@mail.gmail.com>
2019-08-01 11:48 ` Mark Brown
2019-08-14 10:53 ` Ali Burak Parım
2019-08-14 16:02 ` Mark Brown
2019-08-19 8:41 ` Maxime Ripard
2019-08-19 15:45 ` Mark Brown
2019-08-20 14:06 ` Maxime Ripard
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