Dynamic control commands that match the downloadable DSP firmware

Dynamic control commands that match the downloadable DSP firmware

[Peter Hsiang]

Hi Mark and Everyone,

For codecs with a programmable DSP core, one needs to provide the amixer controls for the 'soft' features.  As there could be multiple DSP firmware images for different applications, it would be nice if a single codec driver source can support an unlimited combination of commands for DSP firmware features.  

Rather than hard coding the control commands in the driver directly, wouldn't it be cool if, in addition to the firmware being loaded from file, the control commands information can be loaded from file as well.  Then the driver would dynamically create and install the control commands the same way we already do for the EQ.

What do you think?

Peter

Re: Dynamic control commands that match the downloadable DSP firmware

[Mark Brown]

On Wed, Apr 06, 2011 at 03:51:49PM -0700, Peter Hsiang wrote:
> Hi Mark and Everyone,

As previously mentioned fix your mail client to word wrap within
paragraphs.  Not doing this makes your mails very hard to read and reply
to.  I've reflowed your text.

> Rather than hard coding the control commands in the driver directly,
> wouldn't it be cool if, in addition to the firmware being loaded from
> file, the control commands information can be loaded from file as
> well.  Then the driver would dynamically create and install the
> control commands the same way we already do for the EQ.

Yes, this is one of the topics that's on the agenda for the ASoC
conference next month.  There's some tricks here as for many DSPs there
are sequencing requirements for updating the controls, especially things
like coefficient banks, or constraints on which firmware features can be
active simultaneously both of which make a purely data driven approach
more complex than it could be.

With more complex systems it's not just controls but also DAPM that can
need updating, and of course we also need to manage changing firmwares
at runtime and convincing firmware vendors to supply data that ALSA can
comprehend.