[alsa-devel] [PATCH] ASoC: ak4642: Add Playback Volume control

[Kuninori Morimoto]

Dear Liam, Mark

> > Is this for the "Master Playback Volume" ? If so, It should be "Master
> > Playback Volume"

Now I'm creating V2 patch.
And I have 2 questions

1) name

Manual said this register name is "Digital Volume Control".
In this case, should I use "Digital Playback Volume" ?
or "Master Playback Volume" ?

2) settings

This chip is

> +/*
> + * Playback Volume (table 39)
> + *
> + * max : 0x00 : +12.0 dB
> + *       ( 0.5 dB step )
> + * min : 0xFE : -115.0 dB
> + * mute: 0xFF
> + */

min is 0xFE (-115.0 dB)
and last 0xFF mean "mute".
and DECLARE_TLV_DB_SCALE have "mute" flag.

In this case,

> +static const DECLARE_TLV_DB_SCALE(out_tlv, -11500, 50, 1);

Is this -11500 correct ?
it should be -11550 ?

> +static const struct snd_kcontrol_new ak4642_snd_controls[] = {
> +
> +	SOC_DOUBLE_R_TLV("Playback Volume", L_DVC, R_DVC,
> +			 0, 0xFF, 1, out_tlv),

And here, Is 0xFF correct here ?
Is it 0xFE ?

I asked because I noticed amixer's output seems not correct.
There is 0.5db difference between register and amixer's output.

Best regards
--
Kuninori Morimoto