net: core: add of_find_net_device_by_node()

Add a helper function which allows getting the struct net_device pointer
associated with a given struct device_node pointer. This is useful for
instance for DSA Ethernet devices not backed by a platform_device, but a PCI
device.

Since we need to access net_class which is not accessible outside of
net/core/net-sysfs.c, this helper function is also added here and gated
with CONFIG_OF_NET.

Network devices initialized with SET_NETDEV_DEV() are also taken into
account by checking for dev->parent first and then falling back to
checking the device pointer within struct net_device.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/of_net.h b/include/linux/of_net.h
index 34597c8c1a4c..9cd72aab76fe 100644
--- a/include/linux/of_net.h
+++ b/include/linux/of_net.h
@@ -9,8 +9,11 @@
 
 #ifdef CONFIG_OF_NET
 #include <linux/of.h>
+
+struct net_device;
 extern int of_get_phy_mode(struct device_node *np);
 extern const void *of_get_mac_address(struct device_node *np);
+extern struct net_device *of_find_net_device_by_node(struct device_node *np);
 #else
 static inline int of_get_phy_mode(struct device_node *np)
 {
@@ -21,6 +24,11 @@ static inline const void *of_get_mac_address(struct device_node *np)
 {
         return NULL;
 }
+
+static inline struct net_device *of_find_net_device_by_node(struct device_node *np)
+{
+        return NULL;
+}
 #endif
 
 #endif /* __LINUX_OF_NET_H */