[v1,1/1] ASoC: wm8903: implement DMIC support

  Add DMIC input and routing.

Tested-by: Svyatoslav Ryhel <clamor95@gmail.com> # ASUS TF300T
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
---
 sound/soc/codecs/wm8903.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
  

On Sat, Mar 25, 2023 at 10:36:43AM +0200, Svyatoslav Ryhel wrote:
> Add DMIC input and routing.
> 
> Tested-by: Svyatoslav Ryhel <clamor95@gmail.com> # ASUS TF300T
> Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
> ---
>  sound/soc/codecs/wm8903.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/sound/soc/codecs/wm8903.c b/sound/soc/codecs/wm8903.c
> index 41346e5ec5ad..9c2f0aadcff3 100644
> --- a/sound/soc/codecs/wm8903.c
> +++ b/sound/soc/codecs/wm8903.c
> @@ -9,7 +9,6 @@
>   *
>   * TODO:
>   *  - TDM mode configuration.
> - *  - Digital microphone support.
>   */
>  
>  #include <linux/module.h>
> @@ -816,6 +815,7 @@ SND_SOC_DAPM_INPUT("IN2L"),
>  SND_SOC_DAPM_INPUT("IN2R"),
>  SND_SOC_DAPM_INPUT("IN3L"),
>  SND_SOC_DAPM_INPUT("IN3R"),
> +SND_SOC_DAPM_INPUT("DMIC"),
>  SND_SOC_DAPM_INPUT("DMICDAT"),

There is already a datapath for the DMIC here, DMICDAT. Are you
sure you don't just need to set the "Left/Right ADC Input" muxes
correctly through the ALSA controls?

>  
>  SND_SOC_DAPM_OUTPUT("HPOUTL"),
> @@ -996,6 +996,9 @@ static const struct snd_soc_dapm_route wm8903_intercon[] = {
>  	{ "AIFTXL", NULL, "Left Capture Mux" },
>  	{ "AIFTXR", NULL, "Right Capture Mux" },
>  
> +	{ "ADCL", NULL, "DMIC" },
> +	{ "ADCR", NULL, "DMIC" },
> +

And at any rate these should not be directly connected to the
ADC you need some muxing to indicate whether the DMIC or AMICs
are active. Which the DMICDAT path appears to already have.

Thanks,
Charles
  

пн, 27 бер. 2023 р. о 11:32 Charles Keepax <ckeepax@opensource.cirrus.com> пише:
>
> On Sat, Mar 25, 2023 at 10:36:43AM +0200, Svyatoslav Ryhel wrote:
> > Add DMIC input and routing.
> >
> > Tested-by: Svyatoslav Ryhel <clamor95@gmail.com> # ASUS TF300T
> > Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
> > ---
> >  sound/soc/codecs/wm8903.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/sound/soc/codecs/wm8903.c b/sound/soc/codecs/wm8903.c
> > index 41346e5ec5ad..9c2f0aadcff3 100644
> > --- a/sound/soc/codecs/wm8903.c
> > +++ b/sound/soc/codecs/wm8903.c
> > @@ -9,7 +9,6 @@
> >   *
> >   * TODO:
> >   *  - TDM mode configuration.
> > - *  - Digital microphone support.
> >   */
> >
> >  #include <linux/module.h>
> > @@ -816,6 +815,7 @@ SND_SOC_DAPM_INPUT("IN2L"),
> >  SND_SOC_DAPM_INPUT("IN2R"),
> >  SND_SOC_DAPM_INPUT("IN3L"),
> >  SND_SOC_DAPM_INPUT("IN3R"),
> > +SND_SOC_DAPM_INPUT("DMIC"),
> >  SND_SOC_DAPM_INPUT("DMICDAT"),
>
> There is already a datapath for the DMIC here, DMICDAT. Are you
> sure you don't just need to set the "Left/Right ADC Input" muxes
> correctly through the ALSA controls?
>

I will check once more, but so far I was not able to set the mic to
work with DMICDAT. Only with this patch.

Best regards,
Svyatoslav R.

> >
> >  SND_SOC_DAPM_OUTPUT("HPOUTL"),
> > @@ -996,6 +996,9 @@ static const struct snd_soc_dapm_route wm8903_intercon[] = {
> >       { "AIFTXL", NULL, "Left Capture Mux" },
> >       { "AIFTXR", NULL, "Right Capture Mux" },
> >
> > +     { "ADCL", NULL, "DMIC" },
> > +     { "ADCR", NULL, "DMIC" },
> > +
>
> And at any rate these should not be directly connected to the
> ADC you need some muxing to indicate whether the DMIC or AMICs
> are active. Which the DMICDAT path appears to already have.
>
> Thanks,
> Charles
  

On Mon, Mar 27, 2023 at 11:37:05AM +0300, Svyatoslav Ryhel wrote:
> пн, 27 бер. 2023 р. о 11:32 Charles Keepax <ckeepax@opensource.cirrus.com> пише:
> >
> > On Sat, Mar 25, 2023 at 10:36:43AM +0200, Svyatoslav Ryhel wrote:
> > > Add DMIC input and routing.
> > >
> > > Tested-by: Svyatoslav Ryhel <clamor95@gmail.com> # ASUS TF300T
> > > Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
> > > ---
> > >  sound/soc/codecs/wm8903.c | 5 ++++-
> > >  1 file changed, 4 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/sound/soc/codecs/wm8903.c b/sound/soc/codecs/wm8903.c
> > > index 41346e5ec5ad..9c2f0aadcff3 100644
> > > --- a/sound/soc/codecs/wm8903.c
> > > +++ b/sound/soc/codecs/wm8903.c
> > > @@ -9,7 +9,6 @@
> > >   *
> > >   * TODO:
> > >   *  - TDM mode configuration.
> > > - *  - Digital microphone support.
> > >   */
> > >
> > >  #include <linux/module.h>
> > > @@ -816,6 +815,7 @@ SND_SOC_DAPM_INPUT("IN2L"),
> > >  SND_SOC_DAPM_INPUT("IN2R"),
> > >  SND_SOC_DAPM_INPUT("IN3L"),
> > >  SND_SOC_DAPM_INPUT("IN3R"),
> > > +SND_SOC_DAPM_INPUT("DMIC"),
> > >  SND_SOC_DAPM_INPUT("DMICDAT"),
> >
> > There is already a datapath for the DMIC here, DMICDAT. Are you
> > sure you don't just need to set the "Left/Right ADC Input" muxes
> > correctly through the ALSA controls?
> >
> 
> I will check once more, but so far I was not able to set the mic to
> work with DMICDAT. Only with this patch.
> 

The two should be basically equivalent when the controls are set
right, your patch has:

DMIC -> ADCL

The current code has

DMIC -> Left ADC Input -> ADCL

The only difference is that Left ADC Input sets the ADC_DIG_MIC
bit, but the datasheet clearly indicates that should be
necessary for digital mics to work. Does your system definitely
have DMICs? Without that bit set the decimator should still be
connected to the analogue front end.

Thanks,
Charles
  

пн, 27 бер. 2023 р. о 13:14 Charles Keepax <ckeepax@opensource.cirrus.com> пише:
>
> On Mon, Mar 27, 2023 at 11:37:05AM +0300, Svyatoslav Ryhel wrote:
> > пн, 27 бер. 2023 р. о 11:32 Charles Keepax <ckeepax@opensource.cirrus.com> пише:
> > >
> > > On Sat, Mar 25, 2023 at 10:36:43AM +0200, Svyatoslav Ryhel wrote:
> > > > Add DMIC input and routing.
> > > >
> > > > Tested-by: Svyatoslav Ryhel <clamor95@gmail.com> # ASUS TF300T
> > > > Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
> > > > ---
> > > >  sound/soc/codecs/wm8903.c | 5 ++++-
> > > >  1 file changed, 4 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/sound/soc/codecs/wm8903.c b/sound/soc/codecs/wm8903.c
> > > > index 41346e5ec5ad..9c2f0aadcff3 100644
> > > > --- a/sound/soc/codecs/wm8903.c
> > > > +++ b/sound/soc/codecs/wm8903.c
> > > > @@ -9,7 +9,6 @@
> > > >   *
> > > >   * TODO:
> > > >   *  - TDM mode configuration.
> > > > - *  - Digital microphone support.
> > > >   */
> > > >
> > > >  #include <linux/module.h>
> > > > @@ -816,6 +815,7 @@ SND_SOC_DAPM_INPUT("IN2L"),
> > > >  SND_SOC_DAPM_INPUT("IN2R"),
> > > >  SND_SOC_DAPM_INPUT("IN3L"),
> > > >  SND_SOC_DAPM_INPUT("IN3R"),
> > > > +SND_SOC_DAPM_INPUT("DMIC"),
> > > >  SND_SOC_DAPM_INPUT("DMICDAT"),
> > >
> > > There is already a datapath for the DMIC here, DMICDAT. Are you
> > > sure you don't just need to set the "Left/Right ADC Input" muxes
> > > correctly through the ALSA controls?
> > >
> >
> > I will check once more, but so far I was not able to set the mic to
> > work with DMICDAT. Only with this patch.
> >
>
> The two should be basically equivalent when the controls are set
> right, your patch has:
>
> DMIC -> ADCL
>
> The current code has
>
> DMIC -> Left ADC Input -> ADCL
>
> The only difference is that Left ADC Input sets the ADC_DIG_MIC
> bit, but the datasheet clearly indicates that should be
> necessary for digital mics to work. Does your system definitely
> have DMICs? Without that bit set the decimator should still be
> connected to the analogue front end.
>

You are correct, this patch is not needed. It appears that the
issue was not in routing but in wm8903 gpio configuration.

DMICDAT works as intended.

> Thanks,
> Charles