ASoC: nau8825: add clock management for power saving

Adjust dapm widget to manage clock from power event for power saving.
Signed-off-by: David Lin <CTLIN0@nuvoton.com>
Signed-off-by: Mac Chiang <mac.chiang@intel.com>
Link: https://lore.kernel.org/r/20211025113857.3860951-3-CTLIN0@nuvoton.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/nau8825.c

@@ -47,6 +47,7 @@
 
 static int nau8825_configure_sysclk(struct nau8825 *nau8825,
 		int clk_id, unsigned int freq);
+static bool nau8825_is_jack_inserted(struct regmap *regmap);
 
 struct nau8825_fll {
 	int mclk_src;
@@ -981,6 +982,31 @@ static int nau8825_output_dac_event(struct snd_soc_dapm_widget *w,
 	return 0;
 }
 
+static int system_clock_control(struct snd_soc_dapm_widget *w,
+				struct snd_kcontrol *k, int  event)
+{
+	struct snd_soc_component *component = snd_soc_dapm_to_component(w->dapm);
+	struct nau8825 *nau8825 = snd_soc_component_get_drvdata(component);
+	struct regmap *regmap = nau8825->regmap;
+
+	if (SND_SOC_DAPM_EVENT_OFF(event)) {
+		dev_dbg(nau8825->dev, "system clock control : POWER OFF\n");
+		/* Set clock source to disable or internal clock before the
+		 * playback or capture end. Codec needs clock for Jack
+		 * detection and button press if jack inserted; otherwise,
+		 * the clock should be closed.
+		 */
+		if (nau8825_is_jack_inserted(regmap)) {
+			nau8825_configure_sysclk(nau8825,
+						 NAU8825_CLK_INTERNAL, 0);
+		} else {
+			nau8825_configure_sysclk(nau8825, NAU8825_CLK_DIS, 0);
+		}
+	}
+
+	return 0;
+}
+
 static int nau8825_biq_coeff_get(struct snd_kcontrol *kcontrol,
 				     struct snd_ctl_elem_value *ucontrol)
 {
@@ -1094,6 +1120,9 @@ static const struct snd_kcontrol_new nau8825_dacr_mux =
 static const struct snd_soc_dapm_widget nau8825_dapm_widgets[] = {
 	SND_SOC_DAPM_AIF_OUT("AIFTX", "Capture", 0, NAU8825_REG_I2S_PCM_CTRL2,
 		15, 1),
+	SND_SOC_DAPM_AIF_IN("AIFRX", "Playback", 0, SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_SUPPLY("System Clock", SND_SOC_NOPM, 0, 0,
+			    system_clock_control, SND_SOC_DAPM_POST_PMD),
 
 	SND_SOC_DAPM_INPUT("MIC"),
 	SND_SOC_DAPM_MICBIAS("MICBIAS", NAU8825_REG_MIC_BIAS, 8, 0),
@@ -1182,9 +1211,11 @@ static const struct snd_soc_dapm_route nau8825_dapm_routes[] = {
 	{"ADC", NULL, "ADC Clock"},
 	{"ADC", NULL, "ADC Power"},
 	{"AIFTX", NULL, "ADC"},
+	{"AIFTX", NULL, "System Clock"},
 
-	{"DDACL", NULL, "Playback"},
-	{"DDACR", NULL, "Playback"},
+	{"AIFRX", NULL, "System Clock"},
+	{"DDACL", NULL, "AIFRX"},
+	{"DDACR", NULL, "AIFRX"},
 	{"DDACL", NULL, "DDAC Clock"},
 	{"DDACR", NULL, "DDAC Clock"},
 	{"DACL Mux", "DACL", "DDACL"},