[alsa-devel] [PATCH 8/8] ASoC: rsnd: Add Volume Ramp support

[Kuninori Morimoto]

Hi Mark

Thank you for your feedback

> > amixer set "DVC Out Ramp" 100%		// Mute as default
> > amixer set "DVC Out Ramp Period" 80%
> 
> Normally this would be expressed as an enum with some sort of time
> units.  We did discuss at the mini-summit making a standard way of
> expressing this but nobody did that yet.

OK, I can be a 1st guy :)
The HW setting is like below

    value: mean
    00000: 128 dB/1 step
    00001:  64 dB/1 step
    00010:  32 dB/1 step
    ...
    10101: 0.125 dB/2048 steps
    10110: 0.125 dB/4096 steps
    10111: 0.125 dB/8192 steps

Current "DVC Out Ramp Period" wants to have direct value of register.
But, upstream want to have time like this ?

     amixer set "DVC Out Ramp Period" 15000  // 15sec

> > aplay xxx.wav &
> > amixer set "DVC Out Ramp" 0%		// to Volume 100%
> > amixer set "DVC Out Ramp" 100%		// to Mute
> 
> I'm not sure I quite understand this control - what exactly is this
> setting?  It appears that the ramp value is the opposite of the volume
> we end up with which is a bit odd and the comments suggest that this is
> actually triggering a ramp when normally ramps would be done as part of
> a volume set, mute or power up/down operation.

Current "DVC Out Ramp" want to have direct value of register.
It is...

   000:  1 time
   ...
   031:  0.5 time
   ...
   3FE:  4.1 x 10^-7 time
   3FF:  Mute

Maybe I can used inverted value for it ?

      amixer set "DVC Out Ramp" 100%	// to Volume 100%
      amixer set "DVC Out Ramp" 0%	// to Mute