Codec "virtual multiplexer" representation

Codec "virtual multiplexer" representation

[Petr Kulhavy]

Hi,

I'm writing an ASoC driver for the  TAS5721 amplifier.
This 2.1 amplifier provides a complex configuration of the audio 
channels (3), PWMs(4) and output(4) mappings.
However only few (about 6) configurations really make sense.

I'm trying to model the output configurations in ALSA. In order to avoid 
a complicated set of switches and multiplexers I would like
to add just one multiplexer like control which selects one of these 6 
output configurations and a callback function which sets the proper
registers accordingly (there are 5 affected registers).

Is there a way to create such a "virtual multiplexer" in ALSA?

Thanks
Petr

Re: Codec "virtual multiplexer" representation

[Andreas Dannenberg]

On Wed, Feb 17, 2016 at 05:02:47PM +0100, Petr Kulhavy wrote:
> Hi,
> 
> I'm writing an ASoC driver for the  TAS5721 amplifier.
> This 2.1 amplifier provides a complex configuration of the audio channels
> (3), PWMs(4) and output(4) mappings.
> However only few (about 6) configurations really make sense.

Petr,
on a related note, I'm currently working on a combined driver (85%
complete) for TAS5720/TAS5722 which are nice but relatively simple
Class-D mono amplifiers. Despite almost having the same P/N there is
little to no similarity with TAS5721 (which gives a another example why
one should be careful with wildcard 'x' in driver names) so there is no
case for a combined driver here but let's make sure we align our
namespace to avoid collision:

tas5720.[c|h] - Driver for TAS5720/TAS5722 (WIP by Andreas)
tas5721.[c|h] - Driver for TAS5721 (WIP by Petr)

Regards,

--
Andreas Dannenberg
Texas Instruments Inc


> 
> I'm trying to model the output configurations in ALSA. In order to avoid a
> complicated set of switches and multiplexers I would like
> to add just one multiplexer like control which selects one of these 6 output
> configurations and a callback function which sets the proper
> registers accordingly (there are 5 affected registers).
> 
> Is there a way to create such a "virtual multiplexer" in ALSA?
> 
> Thanks
> Petr
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel@alsa-project.org
> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel

Re: Codec "virtual multiplexer" representation

[Petr Kulhavy]

On 18.02.2016 06:30, Andreas Dannenberg wrote:
>
> Petr,
> on a related note, I'm currently working on a combined driver (85%
> complete) for TAS5720/TAS5722 which are nice but relatively simple
> Class-D mono amplifiers. Despite almost having the same P/N there is
> little to no similarity with TAS5721 (which gives a another example why
> one should be careful with wildcard 'x' in driver names) so there is no
> case for a combined driver here but let's make sure we align our
> namespace to avoid collision:
>
> tas5720.[c|h] - Driver for TAS5720/TAS5722 (WIP by Andreas)
> tas5721.[c|h] - Driver for TAS5721 (WIP by Petr)
>
> Regards,
>
> --
> Andreas Dannenberg
> Texas Instruments Inc
>
Hi Andreas,

thanks for letting me know! In the meantime I have found there is a 
driver for TAS5711, TAS5717 and TAS5719.
The TAS5721 is very similar to the 5711, so I will just update that 
driver rather than creating a new one.

One question came to my mind, which you can perhaps help me to answer as 
you are more familiar with these amplifiers:
what is the usual representation of a 2.1 system in controls? I'm 
wondering that the TAS5711 has just master volume and a double slider 
for Ch1/Ch2, but there is no Ch3 control.
Surely that is needed as well, isn't it?

Regards
Petr