net: phy: Introduce fwnode_get_phy_id()

Extract phy_id from compatible string. This will be used by
fwnode_mdiobus_register_phy() to create phy device using the
phy_id.
Signed-off-by: Calvin Johnson <calvin.johnson@oss.nxp.com>
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Acked-by: Grant Likely <grant.likely@arm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/phy_device.c

@@ -834,6 +834,27 @@ static int get_phy_c22_id(struct mii_bus *bus, int addr, u32 *phy_id)
 	return 0;
 }
 
+/* Extract the phy ID from the compatible string of the form
+ * ethernet-phy-idAAAA.BBBB.
+ */
+int fwnode_get_phy_id(struct fwnode_handle *fwnode, u32 *phy_id)
+{
+	unsigned int upper, lower;
+	const char *cp;
+	int ret;
+
+	ret = fwnode_property_read_string(fwnode, "compatible", &cp);
+	if (ret)
+		return ret;
+
+	if (sscanf(cp, "ethernet-phy-id%4x.%4x", &upper, &lower) != 2)
+		return -EINVAL;
+
+	*phy_id = ((upper & GENMASK(15, 0)) << 16) | (lower & GENMASK(15, 0));
+	return 0;
+}
+EXPORT_SYMBOL(fwnode_get_phy_id);
+
 /**
  * get_phy_device - reads the specified PHY device and returns its @phy_device
  *		    struct

include/linux/phy.h

@@ -1377,6 +1377,7 @@ struct phy_device *phy_device_create(struct mii_bus *bus, int addr, u32 phy_id,
 				     bool is_c45,
 				     struct phy_c45_device_ids *c45_ids);
 #if IS_ENABLED(CONFIG_PHYLIB)
+int fwnode_get_phy_id(struct fwnode_handle *fwnode, u32 *phy_id);
 struct mdio_device *fwnode_mdio_find_device(struct fwnode_handle *fwnode);
 struct phy_device *fwnode_phy_find_device(struct fwnode_handle *phy_fwnode);
 struct phy_device *device_phy_find_device(struct device *dev);
@@ -1385,6 +1386,10 @@ struct phy_device *get_phy_device(struct mii_bus *bus, int addr, bool is_c45);
 int phy_device_register(struct phy_device *phy);
 void phy_device_free(struct phy_device *phydev);
 #else
+static inline int fwnode_get_phy_id(struct fwnode_handle *fwnode, u32 *phy_id)
+{
+	return 0;
+}
 static inline
 struct mdio_device *fwnode_mdio_find_device(struct fwnode_handle *fwnode)
 {