[alsa-devel] [PATCH 10/11] ASoC: codecs: Add AB8500 codec-driver

[Ola Lilja]

On 05/23/2012 07:40 PM, Mark Brown wrote:

> On Wed, May 23, 2012 at 09:04:49AM +0200, Ola Lilja wrote:
>> On 05/08/2012 08:27 PM, Mark Brown wrote:
> 
>> >> +	SOC_ENUM("Charge Pump High Threshold For Low Voltage",
>> >> +		soc_enum_envdeththre),
>> >> +	SOC_ENUM("Charge Pump Low Threshold For Low Voltage",
>> >> +		soc_enum_envdetlthre),
>> >> +	SOC_ENUM("Charge Pump Envelope Detection", soc_enum_envdetcpen),
>> >> +	SOC_ENUM("Charge Pump Envelope Detection Decay Time",
>> >> +		soc_enum_envdettime),
> 
>> > Again, why is this all exposed to userspace?
> 
>> These one we need as ALSA-controls. They are parameters that we can tune during
>> runtime and are not hard-wired in any way.
> 
> This seems incredibly surprising - are you sure the configuration isn't
> simply a case of enabling and disabling the charge pump voltage scaling?


Well, yes. One of the control enables/disables the ability to use another
charge-pump voltage when the signal gets over a certain threshold. The other
parameters are tuning of this theshold and responsiveness. This feature can be
changed during runtime depending of quality vs. powersaving needs.