ASoC: Implement interrupt based WM8994 microphone detection

Support interrupt based microphone bias detection. The WM8994 has two
microphone bias supplies, with detection supported on both. Detection
using GPIOs together with the standard GPIO based jack framework is
already supported via the platform data for the WM8994 core driver.

Note that as well as the microphone bias itself the system clock and
whichever AIF clock is supplying the system clock will need to be
enabled for detection to function.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/wm8994.c

@@ -61,6 +61,12 @@ static int wm8994_retune_mobile_base[] = {
 
 #define WM8994_REG_CACHE_SIZE  0x621
 
+struct wm8994_micdet {
+	struct snd_soc_jack *jack;
+	int det;
+	int shrt;
+};
+
 /* codec private data */
 struct wm8994_priv {
 	struct wm_hubs_data hubs;
@@ -86,6 +92,8 @@ struct wm8994_priv {
 	int retune_mobile_cfg[WM8994_NUM_EQ];
 	struct soc_enum retune_mobile_enum;
 
+	struct wm8994_micdet micdet[2];
+
 	struct wm8994_pdata *pdata;
 };
 
@@ -3702,6 +3710,96 @@ struct snd_soc_codec_device soc_codec_dev_wm8994 = {
 };
 EXPORT_SYMBOL_GPL(soc_codec_dev_wm8994);
 
+/**
+ * wm8994_mic_detect - Enable microphone detection via the WM8994 IRQ
+ *
+ * @codec:   WM8994 codec
+ * @jack:    jack to report detection events on
+ * @micbias: microphone bias to detect on
+ * @det:     value to report for presence detection
+ * @shrt:    value to report for short detection
+ *
+ * Enable microphone detection via IRQ on the WM8994.  If GPIOs are
+ * being used to bring out signals to the processor then only platform
+ * data configuration is needed for WM8903 and processor GPIOs should
+ * be configured using snd_soc_jack_add_gpios() instead.
+ *
+ * Configuration of detection levels is available via the micbias1_lvl
+ * and micbias2_lvl platform data members.
+ */
+int wm8994_mic_detect(struct snd_soc_codec *codec, struct snd_soc_jack *jack,
+		      int micbias, int det, int shrt)
+{
+	struct wm8994_priv *wm8994 = codec->private_data;
+	struct wm8994_micdet *micdet;
+	int reg;
+
+	switch (micbias) {
+	case 1:
+		micdet = &wm8994->micdet[0];
+		break;
+	case 2:
+		micdet = &wm8994->micdet[1];
+		break;
+	default:
+		return -EINVAL;
+	}	
+
+	dev_dbg(codec->dev, "Configuring microphone detection on %d: %x %x\n",
+		micbias, det, shrt);
+
+	/* Store the configuration */
+	micdet->jack = jack;
+	micdet->det = det;
+	micdet->shrt = shrt;
+
+	/* If either of the jacks is set up then enable detection */
+	if (wm8994->micdet[0].jack || wm8994->micdet[1].jack)
+		reg = WM8994_MICD_ENA;
+	else 
+		reg = 0;
+
+	snd_soc_update_bits(codec, WM8994_MICBIAS, WM8994_MICD_ENA, reg);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(wm8994_mic_detect);
+
+static irqreturn_t wm8994_mic_irq(int irq, void *data)
+{
+	struct wm8994_priv *priv = data;
+	struct snd_soc_codec *codec = &priv->codec;
+	int reg;
+	int report;
+
+	reg = snd_soc_read(codec, WM8994_INTERRUPT_RAW_STATUS_2);
+	if (reg < 0) {
+		dev_err(codec->dev, "Failed to read microphone status: %d\n",
+			reg);
+		return IRQ_HANDLED;
+	}
+
+	dev_dbg(codec->dev, "Microphone status: %x\n", reg);
+
+	report = 0;
+	if (reg & WM8994_MIC1_DET_STS)
+		report |= priv->micdet[0].det;
+	if (reg & WM8994_MIC1_SHRT_STS)
+		report |= priv->micdet[0].shrt;
+	snd_soc_jack_report(priv->micdet[0].jack, report,
+			    priv->micdet[0].det | priv->micdet[0].shrt);
+
+	report = 0;
+	if (reg & WM8994_MIC2_DET_STS)
+		report |= priv->micdet[1].det;
+	if (reg & WM8994_MIC2_SHRT_STS)
+		report |= priv->micdet[1].shrt;
+	snd_soc_jack_report(priv->micdet[1].jack, report,
+			    priv->micdet[1].det | priv->micdet[1].shrt);
+
+	return IRQ_HANDLED;
+}
+
 static int wm8994_codec_probe(struct platform_device *pdev)
 {
 	int ret;
@@ -3774,6 +3872,30 @@ static int wm8994_codec_probe(struct platform_device *pdev)
 	}
 			   
 
+	ret = wm8994_request_irq(codec->control_data, WM8994_IRQ_MIC1_DET,
+				 wm8994_mic_irq, "Mic 1 detect", wm8994);
+	if (ret != 0)
+		dev_warn(&pdev->dev,
+			 "Failed to request Mic1 detect IRQ: %d\n", ret);
+
+	ret = wm8994_request_irq(codec->control_data, WM8994_IRQ_MIC1_SHRT,
+				 wm8994_mic_irq, "Mic 1 short", wm8994);
+	if (ret != 0)
+		dev_warn(&pdev->dev,
+			 "Failed to request Mic1 short IRQ: %d\n", ret);
+
+	ret = wm8994_request_irq(codec->control_data, WM8994_IRQ_MIC2_DET,
+				 wm8994_mic_irq, "Mic 2 detect", wm8994);
+	if (ret != 0)
+		dev_warn(&pdev->dev,
+			 "Failed to request Mic2 detect IRQ: %d\n", ret);
+
+	ret = wm8994_request_irq(codec->control_data, WM8994_IRQ_MIC2_SHRT,
+				 wm8994_mic_irq, "Mic 2 short", wm8994);
+	if (ret != 0)
+		dev_warn(&pdev->dev,
+			 "Failed to request Mic2 short IRQ: %d\n", ret);
+
 	/* Remember if AIFnLRCLK is configured as a GPIO.  This should be
 	 * configured on init - if a system wants to do this dynamically
 	 * at runtime we can deal with that then.
@@ -3781,7 +3903,7 @@ static int wm8994_codec_probe(struct platform_device *pdev)
 	ret = wm8994_reg_read(codec->control_data, WM8994_GPIO_1);
 	if (ret < 0) {
 		dev_err(codec->dev, "Failed to read GPIO1 state: %d\n", ret);
-		goto err;
+		goto err_irq;
 	}
 	if ((ret & WM8994_GPN_FN_MASK) != WM8994_GP_FN_PIN_SPECIFIC) {
 		wm8994->lrclk_shared[0] = 1;
@@ -3793,7 +3915,7 @@ static int wm8994_codec_probe(struct platform_device *pdev)
 	ret = wm8994_reg_read(codec->control_data, WM8994_GPIO_6);
 	if (ret < 0) {
 		dev_err(codec->dev, "Failed to read GPIO6 state: %d\n", ret);
-		goto err;
+		goto err_irq;
 	}
 	if ((ret & WM8994_GPN_FN_MASK) != WM8994_GP_FN_PIN_SPECIFIC) {
 		wm8994->lrclk_shared[1] = 1;
@@ -3843,7 +3965,7 @@ static int wm8994_codec_probe(struct platform_device *pdev)
 	ret = snd_soc_register_codec(codec);
 	if (ret != 0) {
 		dev_err(codec->dev, "Failed to register codec: %d\n", ret);
-		goto err;
+		goto err_irq;
 	}
 
 	ret = snd_soc_register_dais(wm8994_dai, ARRAY_SIZE(wm8994_dai));
@@ -3858,6 +3980,11 @@ static int wm8994_codec_probe(struct platform_device *pdev)
 
 err_codec:
 	snd_soc_unregister_codec(codec);
+err_irq:
+	wm8994_free_irq(codec->control_data, WM8994_IRQ_MIC2_SHRT, wm8994);
+	wm8994_free_irq(codec->control_data, WM8994_IRQ_MIC2_DET, wm8994);
+	wm8994_free_irq(codec->control_data, WM8994_IRQ_MIC1_SHRT, wm8994);
+	wm8994_free_irq(codec->control_data, WM8994_IRQ_MIC1_DET, wm8994);
 err:
 	kfree(wm8994);
 	return ret;
@@ -3871,6 +3998,10 @@ static int __devexit wm8994_codec_remove(struct platform_device *pdev)
 	wm8994_set_bias_level(codec, SND_SOC_BIAS_OFF);
 	snd_soc_unregister_dais(wm8994_dai, ARRAY_SIZE(wm8994_dai));
 	snd_soc_unregister_codec(&wm8994->codec);
+	wm8994_free_irq(codec->control_data, WM8994_IRQ_MIC2_SHRT, wm8994);
+	wm8994_free_irq(codec->control_data, WM8994_IRQ_MIC2_DET, wm8994);
+	wm8994_free_irq(codec->control_data, WM8994_IRQ_MIC1_SHRT, wm8994);
+	wm8994_free_irq(codec->control_data, WM8994_IRQ_MIC1_DET, wm8994);
 	kfree(wm8994);
 	wm8994_codec = NULL;
 

sound/soc/codecs/wm8994.h

@@ -23,4 +23,7 @@ extern struct snd_soc_dai wm8994_dai[];
 #define WM8994_FLL1 1
 #define WM8994_FLL2 2
 
+int wm8994_mic_detect(struct snd_soc_codec *codec, struct snd_soc_jack *jack,
+		      int micbias, int det, int shrt);
+
 #endif