[alsa-devel] ASoC: How to declare volume TLV dB scale?

[Clemens Ladisch]

Sergej Sawazki wrote:
> could someone please help me to understand the mixer controls TLV scale?
> What would be the DECLARE_TLV_DB_SCALE values for the following example?
>
> reg. value:  0    ..  0x3ff
> phys. value: 0dB  .. -128dB
> volume:      100% ..  0%(mute)

0% volume would be -∞ dB.

And how are the register values mapped between the min/max values?
Does 0x200 correspond to -64 dB, or 50 % of the sample value, or
50 % of the volume?

> What does TLV actually stand for?

Type-length-value.  It's an implementation detail.


Regards,
Clemens