phy: core: Allow children node to be overridden

In order to more flexibly support device tree bindings, allow drivers to
override the container of the child nodes. By default the device node of
the PHY provider is assumed to be the parent for children, but bindings
may decide to add additional levels for better organization.

Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

1 files changed, 44 insertions, 6 deletions

diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
index e7e574dc667a..b72e9a3b6429 100644
--- a/drivers/phy/phy-core.c
+++ b/drivers/phy/phy-core.c
@@ -141,7 +141,7 @@ static struct phy_provider *of_phy_provider_lookup(struct device_node *node)
 		if (phy_provider->dev->of_node == node)
 			return phy_provider;
 
-		for_each_child_of_node(phy_provider->dev->of_node, child)
+		for_each_child_of_node(phy_provider->children, child)
 			if (child == node)
 				return phy_provider;
 	}
@@ -811,24 +811,59 @@ EXPORT_SYMBOL_GPL(devm_phy_destroy);
 /**
  * __of_phy_provider_register() - create/register phy provider with the framework
  * @dev: struct device of the phy provider
+ * @children: device node containing children (if different from dev->of_node)
  * @owner: the module owner containing of_xlate
  * @of_xlate: function pointer to obtain phy instance from phy provider
  *
  * Creates struct phy_provider from dev and of_xlate function pointer.
  * This is used in the case of dt boot for finding the phy instance from
  * phy provider.
+ *
+ * If the PHY provider doesn't nest children directly but uses a separate
+ * child node to contain the individual children, the @children parameter
+ * can be used to override the default. If NULL, the default (dev->of_node)
+ * will be used. If non-NULL, the device node must be a child (or further
+ * descendant) of dev->of_node. Otherwise an ERR_PTR()-encoded -EINVAL
+ * error code is returned.
  */
 struct phy_provider *__of_phy_provider_register(struct device *dev,
-	struct module *owner, struct phy * (*of_xlate)(struct device *dev,
-	struct of_phandle_args *args))
+	struct device_node *children, struct module *owner,
+	struct phy * (*of_xlate)(struct device *dev,
+				 struct of_phandle_args *args))
 {
 	struct phy_provider *phy_provider;
 
+	/*
+	 * If specified, the device node containing the children must itself
+	 * be the provider's device node or a child (or further descendant)
+	 * thereof.
+	 */
+	if (children) {
+		struct device_node *parent = of_node_get(children), *next;
+
+		while (parent) {
+			if (parent == dev->of_node)
+				break;
+
+			next = of_get_parent(parent);
+			of_node_put(parent);
+			parent = next;
+		}
+
+		if (!parent)
+			return ERR_PTR(-EINVAL);
+
+		of_node_put(parent);
+	} else {
+		children = dev->of_node;
+	}
+
 	phy_provider = kzalloc(sizeof(*phy_provider), GFP_KERNEL);
 	if (!phy_provider)
 		return ERR_PTR(-ENOMEM);
 
 	phy_provider->dev = dev;
+	phy_provider->children = of_node_get(children);
 	phy_provider->owner = owner;
 	phy_provider->of_xlate = of_xlate;
 
@@ -854,8 +889,9 @@ EXPORT_SYMBOL_GPL(__of_phy_provider_register);
  * on the devres data, then, devres data is freed.
  */
 struct phy_provider *__devm_of_phy_provider_register(struct device *dev,
-	struct module *owner, struct phy * (*of_xlate)(struct device *dev,
-	struct of_phandle_args *args))
+	struct device_node *children, struct module *owner,
+	struct phy * (*of_xlate)(struct device *dev,
+				 struct of_phandle_args *args))
 {
 	struct phy_provider **ptr, *phy_provider;
 
@@ -863,7 +899,8 @@ struct phy_provider *__devm_of_phy_provider_register(struct device *dev,
 	if (!ptr)
 		return ERR_PTR(-ENOMEM);
 
-	phy_provider = __of_phy_provider_register(dev, owner, of_xlate);
+	phy_provider = __of_phy_provider_register(dev, children, owner,
+						  of_xlate);
 	if (!IS_ERR(phy_provider)) {
 		*ptr = phy_provider;
 		devres_add(dev, ptr);
@@ -888,6 +925,7 @@ void of_phy_provider_unregister(struct phy_provider *phy_provider)
 
 	mutex_lock(&phy_provider_mutex);
 	list_del(&phy_provider->list);
+	of_node_put(phy_provider->children);
 	kfree(phy_provider);
 	mutex_unlock(&phy_provider_mutex);
 }