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.