[PATCH v2 1/5] regulator: Add of_get_regulator_from_list

[Corentin Labbe <clabbe@xxxxxxxxxxxx>]

of_get_regulator_from_list() permits to get a regulator from a
regulators list.
Then add support for such list in of_get_regulator()

Signed-off-by: Corentin Labbe <clabbe@xxxxxxxxxxxx>
---
 drivers/regulator/core.c | 44 ++++++++++++++++++++++++++++++++++++----
 1 file changed, 40 insertions(+), 4 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 1e54a833f2cf..09578c3595de 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -351,6 +351,33 @@ static void regulator_lock_dependent(struct regulator_dev *rdev,
 	mutex_unlock(&regulator_list_mutex);
 }
 
+/**
+ * of_get_regulator_from_list - get a regulator device node based on supply name
+ * from a DT regulators list
+ * @dev: Device pointer for the consumer (of regulator) device
+ * @np: The device node where to search for regulators list
+ * @supply: regulator supply name
+ *
+ * Extract the regulator device node corresponding to the supply name.
+ * returns the device node corresponding to the regulator if found, else
+ * returns NULL.
+ */
+static struct device_node *of_get_regulator_from_list(struct device *dev,
+						      struct device_node *np,
+						      const char *supply)
+{
+	struct of_phandle_args regspec;
+	int index, ret;
+
+	index = of_property_match_string(np, "regulator-names", supply);
+	if (index >= 0) {
+		ret = of_parse_phandle_with_args(np, "regulators", NULL, index, &regspec);
+		if (ret == 0)
+			return regspec.np;
+	}
+	return NULL;
+}
+
 /**
  * of_get_child_regulator - get a child regulator device node
  * based on supply name
@@ -362,17 +389,23 @@ static void regulator_lock_dependent(struct regulator_dev *rdev,
  * returns the device node corresponding to the regulator if found, else
  * returns NULL.
  */
-static struct device_node *of_get_child_regulator(struct device_node *parent,
-						  const char *prop_name)
+static struct device_node *of_get_child_regulator(struct device *dev,
+						  struct device_node *parent,
+						  const char *supply)
 {
 	struct device_node *regnode = NULL;
 	struct device_node *child = NULL;
+	char prop_name[64]; /* 64 is max size of property name */
 
+	snprintf(prop_name, 64, "%s-supply", supply);
 	for_each_child_of_node(parent, child) {
+		regnode = of_get_regulator_from_list(dev, child, supply);
+		if (regnode)
+			return regnode;
 		regnode = of_parse_phandle(child, prop_name, 0);
 
 		if (!regnode) {
-			regnode = of_get_child_regulator(child, prop_name);
+			regnode = of_get_child_regulator(dev, child, prop_name);
 			if (regnode)
 				goto err_node_put;
 		} else {
@@ -401,12 +434,15 @@ static struct device_node *of_get_regulator(struct device *dev, const char *supp
 	char prop_name[64]; /* 64 is max size of property name */
 
 	dev_dbg(dev, "Looking up %s-supply from device tree\n", supply);
+	regnode = of_get_regulator_from_list(dev, dev->of_node, supply);
+	if (regnode)
+		return regnode;
 
 	snprintf(prop_name, 64, "%s-supply", supply);
 	regnode = of_parse_phandle(dev->of_node, prop_name, 0);
 
 	if (!regnode) {
-		regnode = of_get_child_regulator(dev->of_node, prop_name);
+		regnode = of_get_child_regulator(dev, dev->of_node, supply);
 		if (regnode)
 			return regnode;
 
-- 
2.35.1