ASoC: tlv320aic31xx: Add button press detection

This device can optionally detect headset or microphone button presses.
Add support for this by passing this event to the jack layer.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/codecs/tlv320aic31xx.c b/sound/soc/codecs/tlv320aic31xx.c
index a60cd8c..fa47bfc 100644
--- a/sound/soc/codecs/tlv320aic31xx.c
+++ b/sound/soc/codecs/tlv320aic31xx.c
@@ -1423,10 +1423,21 @@ static irqreturn_t aic31xx_irq(int irq, void *data)
 		dev_err(dev, "Short circuit on Left output is detected\n");
 	if (value & AIC31XX_HPRSCDETECT)
 		dev_err(dev, "Short circuit on Right output is detected\n");
-	if (value & AIC31XX_HSPLUG) {
+	if (value & (AIC31XX_HSPLUG | AIC31XX_BUTTONPRESS)) {
 		unsigned int val;
 		int status = 0;
 
+		ret = regmap_read(aic31xx->regmap, AIC31XX_INTRDACFLAG2,
+				  &val);
+		if (ret) {
+			dev_err(dev, "Failed to read interrupt mask: %d\n",
+				ret);
+			goto exit;
+		}
+
+		if (val & AIC31XX_BUTTONPRESS)
+			status |= SND_JACK_BTN_0;
+
 		ret = regmap_read(aic31xx->regmap, AIC31XX_HSDETECT, &val);
 		if (ret) {
 			dev_err(dev, "Failed to read headset type: %d\n", ret);
@@ -1451,7 +1462,8 @@ static irqreturn_t aic31xx_irq(int irq, void *data)
 	}
 	if (value & ~(AIC31XX_HPLSCDETECT |
 		      AIC31XX_HPRSCDETECT |
-		      AIC31XX_HSPLUG))
+		      AIC31XX_HSPLUG |
+		      AIC31XX_BUTTONPRESS))
 		dev_err(dev, "Unknown DAC interrupt flags: 0x%08x\n", value);
 
 read_overflow:
@@ -1564,6 +1576,7 @@ static int aic31xx_i2c_probe(struct i2c_client *i2c,
 
 		regmap_write(aic31xx->regmap, AIC31XX_INT1CTRL,
 			     AIC31XX_HSPLUGDET |
+			     AIC31XX_BUTTONPRESSDET |
 			     AIC31XX_SC |
 			     AIC31XX_ENGINE);