On 04/11/16 22:31, Clemens Ladisch wrote:
Matt Flax wrote:
I have a sample rate converter IC, which is followed by a DAC. This kind of setup :
SoC chip -> Sample rate conv. chip -> DAC chip
What is the purpose of the converter? What problem does it solve?
It has a lower noise floor then libsamplerate.
How do you construct a machine driver for this setup ?
The original DAC driver will not work correctly, as far as sample rate settings are concerned.
Yes, I was expecting that. Tell me, even in the current ALSA version, is there any support for sample rate converter hardware chains ? Situations where we need to control standard codecs which a after sample rate converters.
Unfortunately the silicon only supports an older 3.14 kernel.
You mean, you paid for _no support_? And now are asking here instead? (Not that a newer kernel version would help ...)
It is the Nexell s5p6818 silicon, community only support at this point. Also I couldn't find any examples of sample rate converter hardware chains in linux/sound/soc ...
Well, if your goal isn't a proper driver for upstream, just hack the existing DAC driver to access the other I²C device, when needed.
Sure, I can do this. I can't find any examples on operating a codec within a codec. Would I export all function symbols and do it that way ?
Regards, Clemens