drivers: regulator: common: allow to specify on by default

Some regulators are enabled by default, however, such condition cannot
be captured now by the regulator driver API. Refactor
regulator_common_init_enable to regulator_common_init (enable removed,
as it also sets mode) and add a new argument to specify such condition.
With this change, regulator_disable() and regulator_is_enabled() work as
expected without a first call to regulator_enable().

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>

drivers/regulator/regulator_common.c

@@ -13,7 +13,7 @@ void regulator_common_data_init(const struct device *dev)
 	data->refcnt = 0;
 }
 
-int regulator_common_init_enable(const struct device *dev)
+int regulator_common_init(const struct device *dev, bool is_enabled)
 {
 	const struct regulator_driver_api *api = dev->api;
 	const struct regulator_common_config *config = dev->config;
@@ -27,7 +27,9 @@ int regulator_common_init_enable(const struct device *dev)
 		}
 	}
 
-	if ((config->flags & REGULATOR_INIT_ENABLED) != 0U) {
+	if (is_enabled) {
+		data->refcnt++;
+	} else if ((config->flags & REGULATOR_INIT_ENABLED) != 0U) {
 		ret = api->enable(dev);
 		if (ret < 0) {
 			return ret;

drivers/regulator/regulator_fake.c

@@ -60,7 +60,7 @@ static int regulator_fake_init(const struct device *dev)
 {
 	regulator_common_data_init(dev);
 
-	return regulator_common_init_enable(dev);
+	return regulator_common_init(dev, false);
 }
 
 /* parent regulator */

drivers/regulator/regulator_fixed.c

@@ -72,7 +72,7 @@ static int regulator_fixed_init(const struct device *dev)
 		return ret;
 	}
 
-	ret = regulator_common_init_enable(dev);
+	ret = regulator_common_init(dev, false);
 	if (ret < 0) {
 		return ret;
 	}

drivers/regulator/regulator_npm6001.c

@@ -603,8 +603,7 @@ static int regulator_npm6001_init(const struct device *dev)
 	if (!device_is_ready(config->p)) {
 		return -ENODEV;
 	}
-
+	return regulator_common_init(dev, false);
-	return regulator_common_init_enable(dev);
 }
 
 static int regulator_npm6001_common_init(const struct device *dev)

drivers/regulator/regulator_pca9420.c

@@ -343,7 +343,7 @@ static int regulator_pca9420_init(const struct device *dev)
 		}
 	}
 
-	return regulator_common_init_enable(dev);
+	return regulator_common_init(dev, false);
 }
 
 int regulator_pca9420_dvs_state_set(const struct device *dev,

include/zephyr/drivers/regulator.h

@@ -194,18 +194,22 @@ struct regulator_common_data {
 void regulator_common_data_init(const struct device *dev);
 
 /**
- * @brief Common function to enable regulator at init time.
+ * @brief Common function to initialize the regulator at init time.
  *
  * This function can be called after drivers initialize the regulator. It
  * will automatically enable the regulator if it is set to `regulator-boot-on`
- * or `regulator-always-on` and increase its usage count.
+ * or `regulator-always-on` and increase its usage count. It will also configure
+ * the regulator mode if `regulator-initial-mode` is set. Regulators that are
+ * enabled by default in hardware, must set @p is_enabled to `true`.
  *
  * @param dev Regulator device instance
+ * @param is_enabled Indicate if the regulator is enabled by default in
+ * hardware.
  *
  * @retval 0 If enabled successfully.
  * @retval -errno Negative errno in case of failure.
  */
-int regulator_common_init_enable(const struct device *dev);
+int regulator_common_init(const struct device *dev, bool is_enabled);
 
 /** @endcond */