[alsa-devel] ASoC: Intel: Enabling LPE audio over I2S on Intel Atom E3815

[Liam Girdwood]

On Wed, 2016-11-23 at 13:22 +0800, Shrirang Bagul wrote:
> Hi,
> 
> I'm attempting to enable audio on Intel Atom E3815. I have a board with RT5660
> codec from Realtek connected to the SoC over I2S2. The codec can be configured
> over I2C bus. The board supports External Mic In and Line Out connections for
> audio.
> 
> I am running Ubuntu 16.04 LTS with kernel v4.4.
> 
> To support RT5660 codec, I have backported patches -
> d01580c ASoC: rt5660: enable MCLK detection
> 2b26dd4 ASoC: rt5660: add rt5660 codec driver
> from https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git
> topic/rt5660 branch
> 
> To support I2S_CLK using MCLK I've also backported the patch to support PMC
> platform clocks -
> [13/17] clk: x86: Add Atom PMC platform clocks (https://patchwork.kernel.org/pat
> ch/9277989/)
> 
> To understand the I2S over LPE architecture for audio I'm referring to the Intel
> Atom Processor E3800: Datasheet (http://www.intel.com/content/dam/www/public/us/
> en/documents/datasheets/atom-e3800-family-datasheet.pdf) and discussions on
> alsa-devel mailing list thread: http://mailman.alsa-project.org/pipermail/alsa-d
> evel/2015-November/100303.html
> 
> After implementing the machine driver byt-rt5660.c (by referring to byt-
> rt5640.c), the CPU DAI baytrail-pcm-audio is registered successfully and the
> fw_sst_0f28.bin-48kHz_i2s_master firmware also is loaded without any errors. It
> is possible to configure the codec controls using alsamixer. 
> 
> However, an attempt to record results in an empty PCM file and no audio is heard
>  if I try to playback using aplay.
> 

I'm assuming the pointer is being incremented on playback ? It's
sometimes helpful to disable pulseaudio and try directly with aplay.

You can also try aplay -Dhw0,0 --test-position

If the position is moving then it's likely the codec mixer configuration
is missing something or your MCLK is missing ?

The record result seems like the DSP is not capturing data. Can you try
again without pulseaudio and use arecord -Dhw:0,0 --test-position. Is
there anything in dmesg after plyback/capture ?
 

> I'm clueless on how to proceed from this point onward in getting the audio to
> work on this board. The ouput of alsa-info.sh, clk_summary & gpio config from
> debugfs and dmesg log is attached with this message. I have published the source
> code here: http://kernel.ubuntu.com/git/snb/ubuntu-xenial.git/log/?h=x-master-au
> dio-test
> 
> I would highly appreciate your help!
> 

Liam