[PATCH 1/3] ASoC: mediatek: mt8188-mt6359: support dynamic pinctrl

[Trevor Wu (吳文良)]

On Tue, 2023-07-25 at 09:06 +0200, AngeloGioacchino Del Regno wrote:
> Il 25/07/23 05:53, Trevor Wu ha scritto:
> > To avoid power leakage, it is recommended to replace the default
> > pinctrl
> > state with dynamic pinctrl since certain audio pinmux functions can
> > remain in a HIGH state even when audio is disabled. Linking pinctrl
> > with
> > DAPM using SND_SOC_DAPM_PINCTRL will ensure that audio pins remain
> > in
> > GPIO mode by default and only switch to an audio function when
> > necessary.
> > 
> > Signed-off-by: Trevor Wu <trevor.wu at mediatek.com>
> > ---
> >   sound/soc/mediatek/mt8188/mt8188-mt6359.c | 21
> > +++++++++++++++++++++
> >   1 file changed, 21 insertions(+)
> > 
> > diff --git a/sound/soc/mediatek/mt8188/mt8188-mt6359.c
> > b/sound/soc/mediatek/mt8188/mt8188-mt6359.c
> > index 7c9e08e6a4f5..667d79f33bf2 100644
> > --- a/sound/soc/mediatek/mt8188/mt8188-mt6359.c
> > +++ b/sound/soc/mediatek/mt8188/mt8188-mt6359.c
> > @@ -246,6 +246,11 @@ static const struct snd_soc_dapm_widget
> > mt8188_mt6359_widgets[] = {
> >   	SND_SOC_DAPM_MIC("Headset Mic", NULL),
> >   	SND_SOC_DAPM_SINK("HDMI"),
> >   	SND_SOC_DAPM_SINK("DP"),
> > +
> > +	/* dynamic pinctrl */
> > +	SND_SOC_DAPM_PINCTRL("ETDM_SPK_PIN", "aud_etdm_spk_on",
> > "aud_etdm_spk_off"),
> > +	SND_SOC_DAPM_PINCTRL("ETDM_HP_PIN", "aud_etdm_hp_on",
> > "aud_etdm_hp_off"),
> > +	SND_SOC_DAPM_PINCTRL("MTKAIF_PIN", "aud_mtkaif_on",
> > "aud_mtkaif_off"),
> >   };
> >   
> >   static const struct snd_kcontrol_new mt8188_mt6359_controls[] = {
> > @@ -267,6 +272,7 @@ static int
> > mt8188_mt6359_mtkaif_calibration(struct snd_soc_pcm_runtime *rtd)
> >   		snd_soc_rtdcom_lookup(rtd, AFE_PCM_NAME);
> >   	struct snd_soc_component *cmpnt_codec =
> >   		asoc_rtd_to_codec(rtd, 0)->component;
> > +	struct snd_soc_dapm_widget *pin_w = NULL, *w;
> >   	struct mtk_base_afe *afe;
> >   	struct mt8188_afe_private *afe_priv;
> >   	struct mtkaif_param *param;
> > @@ -306,6 +312,18 @@ static int
> > mt8188_mt6359_mtkaif_calibration(struct snd_soc_pcm_runtime *rtd)
> >   		return 0;
> >   	}
> >   
> > +	for_each_card_widgets(rtd->card, w) {
> > +		if (!strcmp(w->name, "MTKAIF_PIN")) {
> 
> if (strncmp(w->name, "MTKAIF_PIN", strlen(w->name) == 0) {
> 	pin_w = w;
> 	break;
> }
> 
> That's safer.
> 

If w->name is MTKAIF, the strncmp expression will return 0. However,
the result is not expected. I prefer to keep strcmp here.

> > +			pin_w = w;
> > +			break;
> > +		}
> > +	}
> > +
> > +	if (!pin_w)
> 
> Just a nitpick: you're checking for `if (pin_w)` later in this
> function, so
> to increase readability please do the same here.
> 
> if (pin_w)
> 	dapm_pinctrl_event(...)
> else
> 	dev_dbg(...)
> 

OK. I will update it in v2.

Thanks,
Trevor