ASoC: tlv320aic31xx: Add overflow detection support

Similar to short circuit detection, when the ADC/DAC is saturated and
overflows poor audio quality can result and should be reported to the
user. This device support Automatic Dynamic Range Compression (DRC)
to reduce this but it is not enabled currently in this driver.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/tlv320aic31xx.c

@@ -1409,7 +1409,7 @@ static irqreturn_t aic31xx_irq(int irq, void *data)
 	if (value)
 		handled = true;
 	else
-		goto exit;
+		goto read_overflow;
 
 	if (value & AIC31XX_HPLSCDETECT)
 		dev_err(dev, "Short circuit on Left output is detected\n");
@@ -1419,6 +1419,35 @@ static irqreturn_t aic31xx_irq(int irq, void *data)
 		      AIC31XX_HPRSCDETECT))
 		dev_err(dev, "Unknown DAC interrupt flags: 0x%08x\n", value);
 
+read_overflow:
+	ret = regmap_read(aic31xx->regmap, AIC31XX_OFFLAG, &value);
+	if (ret) {
+		dev_err(dev, "Failed to read overflow flag: %d\n", ret);
+		goto exit;
+	}
+
+	if (value)
+		handled = true;
+	else
+		goto exit;
+
+	if (value & AIC31XX_DAC_OF_LEFT)
+		dev_warn(dev, "Left-channel DAC overflow has occurred\n");
+	if (value & AIC31XX_DAC_OF_RIGHT)
+		dev_warn(dev, "Right-channel DAC overflow has occurred\n");
+	if (value & AIC31XX_DAC_OF_SHIFTER)
+		dev_warn(dev, "DAC barrel shifter overflow has occurred\n");
+	if (value & AIC31XX_ADC_OF)
+		dev_warn(dev, "ADC overflow has occurred\n");
+	if (value & AIC31XX_ADC_OF_SHIFTER)
+		dev_warn(dev, "ADC barrel shifter overflow has occurred\n");
+	if (value & ~(AIC31XX_DAC_OF_LEFT |
+		      AIC31XX_DAC_OF_RIGHT |
+		      AIC31XX_DAC_OF_SHIFTER |
+		      AIC31XX_ADC_OF |
+		      AIC31XX_ADC_OF_SHIFTER))
+		dev_warn(dev, "Unknown overflow interrupt flags: 0x%08x\n", value);
+
 exit:
 	if (handled)
 		return IRQ_HANDLED;
@@ -1499,7 +1528,8 @@ static int aic31xx_i2c_probe(struct i2c_client *i2c,
 				   AIC31XX_GPIO1_FUNC_SHIFT);
 
 		regmap_write(aic31xx->regmap, AIC31XX_INT1CTRL,
-			     AIC31XX_SC);
+			     AIC31XX_SC |
+			     AIC31XX_ENGINE);
 
 		ret = devm_request_threaded_irq(aic31xx->dev, aic31xx->irq,
 						NULL, aic31xx_irq,

sound/soc/codecs/tlv320aic31xx.h

@@ -173,6 +173,13 @@ struct aic31xx_pdata {
 #define AIC31XX_HPRDRVPWRSTATUS_MASK	BIT(1)
 #define AIC31XX_SPRDRVPWRSTATUS_MASK	BIT(0)
 
+/* AIC31XX_OFFLAG */
+#define AIC31XX_DAC_OF_LEFT		BIT(7)
+#define AIC31XX_DAC_OF_RIGHT		BIT(6)
+#define AIC31XX_DAC_OF_SHIFTER		BIT(5)
+#define AIC31XX_ADC_OF			BIT(3)
+#define AIC31XX_ADC_OF_SHIFTER		BIT(1)
+
 /* AIC31XX_INTRDACFLAG */
 #define AIC31XX_HPLSCDETECT		BIT(7)
 #define AIC31XX_HPRSCDETECT		BIT(6)