ASoC: max98090: Fix sequencing when starting additional routes

Enforce correct device sequencing when configuring a new
audio route when there is an existing active audio route(s).

This patch fixed recording noise issue while playback is active.

We have some registers which require the device to be in full shutdown
or to enter full shutdown before the register settings will take effect.
Currently the driver is not shutting down the device when a new audio
route is created. If a new audio route is made active while there is
already an active audio route, then the required register sequencing is
violated. A hardware shutdown toggle when creating a new audio route
corrects the sequencing error. The device must remain in hardware
shutdown for 40ms to allow the internal hardware core to fully shutdown.

Signed-off-by: Fang, Yang A <[e-mail]>
Signed-off-by: Sathyanarayana Nujella <[e-mail]>
Acked-by: Anish Kumar <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

sound/soc/codecs/max98090.c

···
 	return 0;
 }
 
+static int max98090_shdn_event(struct snd_soc_dapm_widget *w,
+				 struct snd_kcontrol *kcontrol, int event)
+{
+	struct snd_soc_codec *codec = snd_soc_dapm_to_codec(w->dapm);
+	struct max98090_priv *max98090 = snd_soc_codec_get_drvdata(codec);
+
+	if (event & SND_SOC_DAPM_POST_PMU)
+		max98090->shdn_pending = true;
+
+	return 0;
+
+}
+
 static const char *mic1_mux_text[] = { "IN12", "IN56" };
 
 static SOC_ENUM_SINGLE_DECL(mic1_mux_enum,
···
 	SND_SOC_DAPM_SUPPLY("SDOEN", M98090_REG_IO_CONFIGURATION,
 		M98090_SDOEN_SHIFT, 0, NULL, 0),
 	SND_SOC_DAPM_SUPPLY("DMICL_ENA", M98090_REG_DIGITAL_MIC_ENABLE,
-		 M98090_DIGMICL_SHIFT, 0, NULL, 0),
+		 M98090_DIGMICL_SHIFT, 0, max98090_shdn_event,
+			SND_SOC_DAPM_POST_PMU),
 	SND_SOC_DAPM_SUPPLY("DMICR_ENA", M98090_REG_DIGITAL_MIC_ENABLE,
-		 M98090_DIGMICR_SHIFT, 0, NULL, 0),
+		 M98090_DIGMICR_SHIFT, 0, max98090_shdn_event,
+			 SND_SOC_DAPM_POST_PMU),
 	SND_SOC_DAPM_SUPPLY("AHPF", M98090_REG_FILTER_CONFIG,
 		M98090_AHPF_SHIFT, 0, NULL, 0),
 
···
 		&max98090_right_adc_mixer_controls[0],
 		ARRAY_SIZE(max98090_right_adc_mixer_controls)),
 
-	SND_SOC_DAPM_ADC("ADCL", NULL, M98090_REG_INPUT_ENABLE,
-		M98090_ADLEN_SHIFT, 0),
-	SND_SOC_DAPM_ADC("ADCR", NULL, M98090_REG_INPUT_ENABLE,
-		M98090_ADREN_SHIFT, 0),
+	SND_SOC_DAPM_ADC_E("ADCL", NULL, M98090_REG_INPUT_ENABLE,
+		M98090_ADLEN_SHIFT, 0, max98090_shdn_event,
+		SND_SOC_DAPM_POST_PMU),
+	SND_SOC_DAPM_ADC_E("ADCR", NULL, M98090_REG_INPUT_ENABLE,
+		M98090_ADREN_SHIFT, 0, max98090_shdn_event,
+		SND_SOC_DAPM_POST_PMU),
 
 	SND_SOC_DAPM_AIF_OUT("AIFOUTL", "HiFi Capture", 0,
 		SND_SOC_NOPM, 0, 0),
···
 	return 0;
 }
 
+static void max98090_seq_notifier(struct snd_soc_dapm_context *dapm,
+	enum snd_soc_dapm_type event, int subseq)
+{
+	struct snd_soc_codec *codec = snd_soc_dapm_to_codec(dapm);
+	struct max98090_priv *max98090 = snd_soc_codec_get_drvdata(codec);
+
+	if (max98090->shdn_pending) {
+		snd_soc_update_bits(codec, M98090_REG_DEVICE_SHUTDOWN,
+				M98090_SHDNN_MASK, 0);
+		msleep(40);
+		snd_soc_update_bits(codec, M98090_REG_DEVICE_SHUTDOWN,
+				M98090_SHDNN_MASK, M98090_SHDNN_MASK);
+		max98090->shdn_pending = false;
+	}
+}
+
 static struct snd_soc_codec_driver soc_codec_dev_max98090 = {
 	.probe   = max98090_probe,
 	.remove  = max98090_remove,
+	.seq_notifier = max98090_seq_notifier,
 	.set_bias_level = max98090_set_bias_level,
 };
 

sound/soc/codecs/max98090.h

···
 	unsigned int pa2en;
 	unsigned int sidetone;
 	bool master;
+	bool shdn_pending;
 };
 
 int max98090_mic_detect(struct snd_soc_codec *codec,