phy: core: Add an exported of_phy_get function

Previously the of_phy_get function took a struct device * and
was declared static. It was impossible to call it from
another driver and thus it was impossible to get phy defined
for a given node. The old function was renamed to _of_phy_get
and was left for internal use. of_phy_get function was added
and it was exported. The function enables to get a phy for
a given device tree node.

Signed-off-by: Kamil Debski <k.debski@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

drivers/phy/phy-core.c

@@ -274,8 +274,8 @@ int phy_power_off(struct phy *phy)
 EXPORT_SYMBOL_GPL(phy_power_off);
 
 /**
- * of_phy_get() - lookup and obtain a reference to a phy by phandle
- * @dev: device that requests this phy
+ * _of_phy_get() - lookup and obtain a reference to a phy by phandle
+ * @np: device_node for which to get the phy
  * @index: the index of the phy
  *
  * Returns the phy associated with the given phandle value,
@@ -284,20 +284,17 @@ EXPORT_SYMBOL_GPL(phy_power_off);
  * not yet loaded. This function uses of_xlate call back function provided
  * while registering the phy_provider to find the phy instance.
  */
-static struct phy *of_phy_get(struct device *dev, int index)
+static struct phy *_of_phy_get(struct device_node *np, int index)
 {
 	int ret;
 	struct phy_provider *phy_provider;
 	struct phy *phy = NULL;
 	struct of_phandle_args args;
 
-	ret = of_parse_phandle_with_args(dev->of_node, "phys", "#phy-cells",
+	ret = of_parse_phandle_with_args(np, "phys", "#phy-cells",
 		index, &args);
-	if (ret) {
-		dev_dbg(dev, "failed to get phy in %s node\n",
-			dev->of_node->full_name);
+	if (ret)
 		return ERR_PTR(-ENODEV);
-	}
 
 	mutex_lock(&phy_provider_mutex);
 	phy_provider = of_phy_provider_lookup(args.np);
@@ -316,6 +313,36 @@ err0:
 	return phy;
 }
 
+/**
+ * of_phy_get() - lookup and obtain a reference to a phy using a device_node.
+ * @np: device_node for which to get the phy
+ * @con_id: name of the phy from device's point of view
+ *
+ * Returns the phy driver, after getting a refcount to it; or
+ * -ENODEV if there is no such phy. The caller is responsible for
+ * calling phy_put() to release that count.
+ */
+struct phy *of_phy_get(struct device_node *np, const char *con_id)
+{
+	struct phy *phy = NULL;
+	int index = 0;
+
+	if (con_id)
+		index = of_property_match_string(np, "phy-names", con_id);
+
+	phy = _of_phy_get(np, index);
+	if (IS_ERR(phy))
+		return phy;
+
+	if (!try_module_get(phy->ops->owner))
+		return ERR_PTR(-EPROBE_DEFER);
+
+	get_device(&phy->dev);
+
+	return phy;
+}
+EXPORT_SYMBOL_GPL(of_phy_get);
+
 /**
  * phy_put() - release the PHY
  * @phy: the phy returned by phy_get()
@@ -407,7 +434,7 @@ struct phy *phy_get(struct device *dev, const char *string)
 	if (dev->of_node) {
 		index = of_property_match_string(dev->of_node, "phy-names",
 			string);
-		phy = of_phy_get(dev, index);
+		phy = _of_phy_get(dev->of_node, index);
 	} else {
 		phy = phy_lookup(dev, string);
 	}

include/linux/phy/phy.h

@@ -151,6 +151,7 @@ struct phy *devm_phy_get(struct device *dev, const char *string);
 struct phy *devm_phy_optional_get(struct device *dev, const char *string);
 void phy_put(struct phy *phy);
 void devm_phy_put(struct device *dev, struct phy *phy);
+struct phy *of_phy_get(struct device_node *np, const char *con_id);
 struct phy *of_phy_simple_xlate(struct device *dev,
 	struct of_phandle_args *args);
 struct phy *phy_create(struct device *dev, const struct phy_ops *ops,
@@ -259,6 +260,11 @@ static inline void devm_phy_put(struct device *dev, struct phy *phy)
 {
 }
 
+static inline struct phy *of_phy_get(struct device_node *np, const char *con_id)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
 static inline struct phy *of_phy_simple_xlate(struct device *dev,
 	struct of_phandle_args *args)
 {