drivers: regulator: npm1300: Set voltage checks existing setting

Regulator voltage setting is not applied if the device output
is already configured for the requested voltage.
This change is needed to ensure correct device behaviour.

Signed-off-by: Andy Sinclair <[email protected]>

drivers/regulator/regulator_npm1300.c

@@ -141,10 +141,33 @@ static int retention_set_voltage(const struct device *dev, int32_t retention_uv)
 				     idx);
 }
 
+static int buck_get_voltage_index(const struct device *dev, uint8_t chan, uint8_t *idx)
+{
+	const struct regulator_npm1300_config *config = dev->config;
+	uint8_t sel;
+	int ret;
+
+	ret = mfd_npm1300_reg_read(config->mfd, BUCK_BASE, BUCK_OFFSET_SW_CTRL, &sel);
+
+	if (ret < 0) {
+		return ret;
+	}
+
+	if ((sel >> chan) & 1U) {
+		/* SW control */
+		return mfd_npm1300_reg_read(config->mfd, BUCK_BASE,
+					    BUCK_OFFSET_VOUT_NORM + (chan * 2U), idx);
+	}
+
+	/* VSET pin control */
+	return mfd_npm1300_reg_read(config->mfd, BUCK_BASE, BUCK_OFFSET_VOUT_STAT + chan, idx);
+}
+
 static int buck_set_voltage(const struct device *dev, uint8_t chan, int32_t min_uv, int32_t max_uv)
 {
 	const struct regulator_npm1300_config *config = dev->config;
 	uint8_t mask;
+	uint8_t curr_idx;
 	uint16_t idx;
 	int ret;
 
@@ -154,6 +177,13 @@ static int buck_set_voltage(const struct device *dev, uint8_t chan, int32_t min_
 		return ret;
 	}
 
+	/* Get current setting, and return if current and new index match */
+	ret = buck_get_voltage_index(dev, chan, &curr_idx);
+
+	if ((ret < 0) || (idx == curr_idx)) {
+		return ret;
+	}
+
 	ret = mfd_npm1300_reg_write(config->mfd, BUCK_BASE, BUCK_OFFSET_VOUT_NORM + (chan * 2U),
 				    idx);
 
@@ -201,26 +231,10 @@ int regulator_npm1300_set_voltage(const struct device *dev, int32_t min_uv, int3
 
 static int buck_get_voltage(const struct device *dev, uint8_t chan, int32_t *volt_uv)
 {
-	const struct regulator_npm1300_config *config = dev->config;
-	uint8_t sel;
 	uint8_t idx;
 	int ret;
 
-	ret = mfd_npm1300_reg_read(config->mfd, BUCK_BASE, BUCK_OFFSET_SW_CTRL, &sel);
-
-	if (ret < 0) {
-		return ret;
-	}
-
-	if ((sel >> chan) & 1U) {
-		/* SW control */
-		ret = mfd_npm1300_reg_read(config->mfd, BUCK_BASE,
-					   BUCK_OFFSET_VOUT_NORM + (chan * 2U), &idx);
-	} else {
-		/* VSET pin control */
-		ret = mfd_npm1300_reg_read(config->mfd, BUCK_BASE, BUCK_OFFSET_VOUT_STAT + chan,
-					   &idx);
-	}
+	ret = buck_get_voltage_index(dev, chan, &idx);
 
 	if (ret < 0) {
 		return ret;