drivers: regulator: add common init enable API

Add a new API for drivers that can be called to initialize the regulator
at init time if `regulator-boot-on` or `regulator-always-on` are set.

Signed-off-by: Gerard Marull-Paretas <[email protected]>

Author: gmarull

drivers/regulator/regulator_common.c

@@ -14,6 +14,30 @@ void regulator_common_data_init(const struct device *dev)
 	data->refcnt = 0;
 }
 
+int regulator_common_init_enable(const struct device *dev)
+{
+	const struct regulator_common_config *config =
+		(struct regulator_common_config *)dev->config;
+	struct regulator_common_data *data =
+		(struct regulator_common_data *)dev->data;
+
+	if ((config->flags & REGULATOR_INIT_ENABLED) != 0U) {
+		const struct regulator_driver_api *api =
+			(const struct regulator_driver_api *)dev->api;
+
+		int ret;
+
+		ret = api->enable(dev);
+		if (ret < 0) {
+			return ret;
+		}
+
+		data->refcnt++;
+	}
+
+	return 0;
+}
+
 int regulator_enable(const struct device *dev)
 {
 	const struct regulator_driver_api *api =

drivers/regulator/regulator_fixed.c

@@ -67,18 +67,18 @@ static int regulator_fixed_init(const struct device *dev)
 		return -ENODEV;
 	}
 
-	if ((cfg->common.flags & REGULATOR_INIT_ENABLED) != 0U) {
-		ret = gpio_pin_configure_dt(&cfg->enable, GPIO_OUTPUT_ACTIVE);
-		if (ret < 0) {
-			return ret;
-		}
+	ret = gpio_pin_configure_dt(&cfg->enable, GPIO_OUTPUT_INACTIVE);
+	if (ret < 0) {
+		return ret;
+	}
+
+	ret = regulator_common_init_enable(dev);
+	if (ret < 0) {
+		return ret;
+	}
 
+	if (regulator_is_enabled(dev)) {
 		k_busy_wait(cfg->startup_delay_us);
-	} else {
-		ret = gpio_pin_configure_dt(&cfg->enable, GPIO_OUTPUT_INACTIVE);
-		if (ret < 0) {
-			return ret;
-		}
 	}
 
 	return 0;

drivers/regulator/regulator_pca9420.c

@@ -300,7 +300,6 @@ static int regulator_pca9420_init(const struct device *dev)
 {
 	const struct regulator_pca9420_config *config = dev->config;
 	const struct regulator_pca9420_common_config *cconfig = config->parent->config;
-	int rc  = 0;
 
 	regulator_common_data_init(dev);
 
@@ -344,11 +343,7 @@ static int regulator_pca9420_init(const struct device *dev)
 		}
 	}
 
-	if ((config->common.flags & REGULATOR_INIT_ENABLED) != 0U) {
-		rc = regulator_pca9420_enable(dev);
-	}
-
-	return rc;
+	return regulator_common_init_enable(dev);
 }
 
 int regulator_pca9420_dvs_state_set(const struct device *dev,

include/zephyr/drivers/regulator.h

@@ -153,6 +153,20 @@ struct regulator_common_data {
  */
 void regulator_common_data_init(const struct device *dev);
 
+/**
+ * @brief Common function to enable 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.
+ *
+ * @param dev Regulator device instance
+ *
+ * @retval 0 If enabled successfully.
+ * @retval -errno Negative errno in case of failure.
+ */
+int regulator_common_init_enable(const struct device *dev);
+
 /** @endcond */
 
 /**