extcon: max8997: Set default of ADC debounce time during initialization

This patch set default of ADC Debounce Time(25ms) during probe step.
Also, can possible change ADC Debounce Time according to H/W situation
by using max8997_set_adc_debounce_time()

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>
diff --git a/drivers/extcon/extcon-max8997.c b/drivers/extcon/extcon-max8997.c
index 8739b50..3206daa 100644
--- a/drivers/extcon/extcon-max8997.c
+++ b/drivers/extcon/extcon-max8997.c
@@ -30,6 +30,13 @@
 
 #define	DEV_NAME			"max8997-muic"
 
+enum max8997_muic_adc_debounce_time {
+	ADC_DEBOUNCE_TIME_0_5MS = 0,	/* 0.5ms */
+	ADC_DEBOUNCE_TIME_10MS,		/* 10ms */
+	ADC_DEBOUNCE_TIME_25MS,		/* 25ms */
+	ADC_DEBOUNCE_TIME_38_62MS,	/* 38.62ms */
+};
+
 struct max8997_muic_irq {
 	unsigned int irq;
 	const char *name;
@@ -95,6 +102,38 @@
 };
 
 /*
+ * max8997_muic_set_debounce_time - Set the debounce time of ADC
+ * @info: the instance including private data of max8997 MUIC
+ * @time: the debounce time of ADC
+ */
+static int max8997_muic_set_debounce_time(struct max8997_muic_info *info,
+		enum max8997_muic_adc_debounce_time time)
+{
+	int ret;
+
+	switch (time) {
+	case ADC_DEBOUNCE_TIME_0_5MS:
+	case ADC_DEBOUNCE_TIME_10MS:
+	case ADC_DEBOUNCE_TIME_25MS:
+	case ADC_DEBOUNCE_TIME_38_62MS:
+		ret = max8997_update_reg(info->muic,
+					  MAX8997_MUIC_REG_CONTROL3,
+					  time << CONTROL3_ADCDBSET_SHIFT,
+					  CONTROL3_ADCDBSET_MASK);
+		if (ret) {
+			dev_err(info->dev, "failed to set ADC debounce time\n");
+			return -EAGAIN;
+		}
+		break;
+	default:
+		dev_err(info->dev, "invalid ADC debounce time\n");
+		return -EINVAL;
+	}
+
+	return 0;
+};
+
+/*
  * max8997_muic_set_path - Set hardware line according to attached cable
  * @info: the instance including private data of max8997 MUIC
  * @value: the path according to attached cable
@@ -507,6 +546,9 @@
 		}
 	}
 
+	/* Set ADC debounce time */
+	max8997_muic_set_debounce_time(info, ADC_DEBOUNCE_TIME_25MS);
+
 	/* Initial device detection */
 	max8997_muic_detect_dev(info);