[alsa-devel] Patches to bind the SGTL5000 chip to AM33XX McASP

[Peter Ujfalusi]

Greg,

On 03/19/2015 07:48 PM, Greg Knight wrote:
>> For a codec such as the SGTL5000 I would connect a clock, which is
> running all
>> the time. If you take a look at the driver, it enables the clock at
> probe and
>> leaves it running as long as the driver is loaded.
> 
> Speaking briefly to my "electrical" colleague, he's a bit concerned
> about the extra power load that a crystal oscillator might incur, while
> I'm concerned about audio quality from a source like CLKOUT2.
> 
> Is there a straightforward way we could enable the clock on-demand -
> when we're communicating with the codec/mixer or actually using the
> audio subsystem - while keeping it disabled when not in use? We don't
> expect to be using the audio subsystem frequently.
> 
> Worst-case we can set up a GPIO and enable/disable it as needed in
> user-space - acceptable, if annoying, for our application.

See my reply to Nikolay.

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