[alsa-devel] [PATCH 1/2] ASoC: wm8960: correct the min gain value of some PGA

[Zidan Wang]

On Wed, Sep 09, 2015 at 12:49:54PM +0100, Charles Keepax wrote:
> On Wed, Sep 09, 2015 at 07:29:10PM +0800, Zidan Wang wrote:
> > The min gain is the corresponding gain value when the register value is 0
> > instead of 1, just correct it.
> > 
> > Signed-off-by: Zidan Wang <zidan.wang at freescale.com>
> > ---
> >  sound/soc/codecs/wm8960.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c
> > index e3b7d0c..6163474 100644
> > --- a/sound/soc/codecs/wm8960.c
> > +++ b/sound/soc/codecs/wm8960.c
> > @@ -211,11 +211,11 @@ static int wm8960_put_deemph(struct snd_kcontrol *kcontrol,
> >  	return wm8960_set_deemph(codec);
> >  }
> >  
> > -static const DECLARE_TLV_DB_SCALE(adc_tlv, -9700, 50, 0);
> > -static const DECLARE_TLV_DB_SCALE(dac_tlv, -12700, 50, 1);
> > +static const DECLARE_TLV_DB_SCALE(adc_tlv, -9750, 50, 1);
> > +static const DECLARE_TLV_DB_SCALE(dac_tlv, -12750, 50, 1);
> 
> The value zero is used for digital mute here. So I don't think it
> is really appropriate to extend the TLV to show it as -97.5dB or
> -127.5dB.

I think the min register value will corresponding to the min gain.
So value 0 will also have a gain value, although it's for digital mute.

Refer to wm8962 codec driver, beep gain range is -90db~-6db, step in 6db,
but it define the beep gain like below:
static const DECLARE_TLV_DB_SCALE(beep_tlv, -9600, 600, 1);

Best Regards,
Zidan Wang
> 
> >  static const DECLARE_TLV_DB_SCALE(bypass_tlv, -2100, 300, 0);
> >  static const DECLARE_TLV_DB_SCALE(out_tlv, -12100, 100, 1);
> > -static const DECLARE_TLV_DB_SCALE(boost_tlv, -1200, 300, 1);
> > +static const DECLARE_TLV_DB_SCALE(boost_tlv, -1500, 300, 1);
> 
> Same here.
> 
> >  
> >  static const struct snd_kcontrol_new wm8960_snd_controls[] = {
> >  SOC_DOUBLE_R_TLV("Capture Volume", WM8960_LINVOL, WM8960_RINVOL,
> > -- 
> > 1.9.1
> 
> Thanks,
> Charles