tree adad60778fda9a939c94cf2ecbb579ddb00e75fb
parent 304eb0a8e5a0d76e7a069f9b87cb3b8499b1f07c
author Richard Fitzgerald <rf@opensource.wolfsonmicro.com> 1395927335 +0000
committer Richard Fitzgerald <rf@opensource.wolfsonmicro.com> 1399284900 +0100

audio_hw: Correct scaling of volume setting

Android passes volume as a float multiplier value
that has already been converted from logarithmic decibels
into a linear sample multiplier. ALSA volume controls
use a logarithmic sequence so we must convert the values
we get from Android back into a decibel scale.

Change-Id: I5f5d95cb923fa0a3b4bbb6acf1de6316e571904b
Signed-off-by: lihui<hui.li@capelabs.com>
Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>