device property: Introduce fwnode_get_mac_address()

Until now there were two almost identical functions for
obtaining MAC address - of_get_mac_address() and, more generic,
device_get_mac_address(). However it is not uncommon,
that the network interface is represented as a child
of the actual controller, hence it is not associated
directly to any struct device, required by the latter
routine.

This commit allows for getting the MAC address for
children nodes in the ACPI world by introducing a new function -
fwnode_get_mac_address(). This commit also changes
device_get_mac_address() routine to be its wrapper, in order
to prevent unnecessary duplication.
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/base/property.c

@@ -1153,11 +1153,11 @@ int device_get_phy_mode(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(device_get_phy_mode);
 
-static void *device_get_mac_addr(struct device *dev,
+static void *fwnode_get_mac_addr(struct fwnode_handle *fwnode,
 				 const char *name, char *addr,
 				 int alen)
 {
-	int ret = device_property_read_u8_array(dev, name, addr, alen);
+	int ret = fwnode_property_read_u8_array(fwnode, name, addr, alen);
 
 	if (ret == 0 && alen == ETH_ALEN && is_valid_ether_addr(addr))
 		return addr;
@@ -1165,8 +1165,8 @@ static void *device_get_mac_addr(struct device *dev,
 }
 
 /**
- * device_get_mac_address - Get the MAC for a given device
- * @dev:	Pointer to the device
+ * fwnode_get_mac_address - Get the MAC from the firmware node
+ * @fwnode:	Pointer to the firmware node
  * @addr:	Address of buffer to store the MAC in
  * @alen:	Length of the buffer pointed to by addr, should be ETH_ALEN
  *
@@ -1187,19 +1187,31 @@ static void *device_get_mac_addr(struct device *dev,
  * In this case, the real MAC is in 'local-mac-address', and 'mac-address'
  * exists but is all zeros.
 */
-void *device_get_mac_address(struct device *dev, char *addr, int alen)
+void *fwnode_get_mac_address(struct fwnode_handle *fwnode, char *addr, int alen)
 {
 	char *res;
 
-	res = device_get_mac_addr(dev, "mac-address", addr, alen);
+	res = fwnode_get_mac_addr(fwnode, "mac-address", addr, alen);
 	if (res)
 		return res;
 
-	res = device_get_mac_addr(dev, "local-mac-address", addr, alen);
+	res = fwnode_get_mac_addr(fwnode, "local-mac-address", addr, alen);
 	if (res)
 		return res;
 
-	return device_get_mac_addr(dev, "address", addr, alen);
+	return fwnode_get_mac_addr(fwnode, "address", addr, alen);
+}
+EXPORT_SYMBOL(fwnode_get_mac_address);
+
+/**
+ * device_get_mac_address - Get the MAC for a given device
+ * @dev:	Pointer to the device
+ * @addr:	Address of buffer to store the MAC in
+ * @alen:	Length of the buffer pointed to by addr, should be ETH_ALEN
+ */
+void *device_get_mac_address(struct device *dev, char *addr, int alen)
+{
+	return fwnode_get_mac_address(dev_fwnode(dev), addr, alen);
 }
 EXPORT_SYMBOL(device_get_mac_address);
 

include/linux/property.h

@@ -279,6 +279,8 @@ int device_get_phy_mode(struct device *dev);
 
 void *device_get_mac_address(struct device *dev, char *addr, int alen);
 
+void *fwnode_get_mac_address(struct fwnode_handle *fwnode,
+			     char *addr, int alen);
 struct fwnode_handle *fwnode_graph_get_next_endpoint(
 	const struct fwnode_handle *fwnode, struct fwnode_handle *prev);
 struct fwnode_handle *