[alsa-devel] [PATCH] Try to support analog audio codec at firefly reload

[John Keeping]

On Tue, Aug 16, 2016 at 04:42:06AM +0800, Randy Li wrote:
>   This patch could enabled the es8328 codec at firefly reload board,
> but it doesn't not really work. I disable the mute of channel 
> Left mix and Right mix in alsamixer, I could hear the noise from
> my headphone, but it never be a music. 
>   I just send this patch here to see whether somebody could figure
> out what is wrong, I am really not familiar with sound.

Have you tried adding an mclk-fs setting to the simple-audio-card?  You
probably want to set it to 256, which will allow 44.1kHz, 48kHz, 88.2kHz
and 96kHz at the codec.  This will give more functionality than pinning
the clock to a specific rate.

For the Rock2 Square, I write a machine driver for the sound because the
headphone GPIO setup cannot be made to work with simple-audio-card; I
found the Firefly Reload schematic and it looks like the configuration
hardware is very similar.  It's a bit of a mess but you can find it on
Github [1] if you want to take a look.

[1] https://github.com/johnkeeping/linux/tree/topic/audio