net: phy: add ofnode node to struct phy_device

Now the UCLASS_ETH device "node" field is owerwritten by some network drivers in
case of Ethernet PHYs which are linked to UCLASS_ETH device using
"phy-handle" DT property and when Ethernet PHY driver needs to read some
additional information from DT. In such cases following happens (in
general):

- network drivers
	priv->phydev = phy_connect(priv->bus, priv->phyaddr, dev,
				   priv->interface);
	<-- phydev is connected to dev which is UCLASS_ETH device

	if (priv->phy_of_handle > 0)
		dev_set_of_offset(priv->phydev->dev, priv->phy_of_handle);
	<-- phydev->dev->node is overwritten by phy-handle DT node

- PHY driver in .config() callback
	int node = dev_of_offset(dev);
	<-- PHY driver uses overwritten dev->node
        const void *fdt = gd->fdt_blob;

	 if (fdtdec_get_bool(fdt, node, "property"))
		...

As result, UCLASS_ETH device can't be used any more for DT accessing.

This patch adds additional ofnode node field to struct phy_device which can
be set explicitly by network drivers and used by PHY drivers, so
overwriting can be avoided. Also add helper function phy_get_ofnode()
which will check and return phy_device->node or dev_ofnode(phydev->dev) for
backward compatibility with existing drivers.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

drivers/net/phy/phy.c

@@ -642,6 +642,10 @@ static struct phy_device *phy_device_create(struct mii_dev *bus, int addr,
 	dev->link = 0;
 	dev->interface = interface;
 
+#ifdef CONFIG_DM_ETH
+	dev->node = ofnode_null();
+#endif
+
 	dev->autoneg = AUTONEG_ENABLE;
 
 	dev->addr = addr;

include/phy.h

@@ -9,6 +9,7 @@
 #ifndef _PHY_H
 #define _PHY_H
 
+#include <dm.h>
 #include <linux/list.h>
 #include <linux/mii.h>
 #include <linux/ethtool.h>
@@ -112,6 +113,7 @@ struct phy_device {
 
 #ifdef CONFIG_DM_ETH
 	struct udevice *dev;
+	ofnode node;
 #else
 	struct eth_device *dev;
 #endif
@@ -182,11 +184,22 @@ void phy_connect_dev(struct phy_device *phydev, struct udevice *dev);
 struct phy_device *phy_connect(struct mii_dev *bus, int addr,
 				struct udevice *dev,
 				phy_interface_t interface);
+static inline ofnode phy_get_ofnode(struct phy_device *phydev)
+{
+	if (ofnode_valid(phydev->node))
+		return phydev->node;
+	else
+		return dev_ofnode(phydev->dev);
+}
 #else
 void phy_connect_dev(struct phy_device *phydev, struct eth_device *dev);
 struct phy_device *phy_connect(struct mii_dev *bus, int addr,
 				struct eth_device *dev,
 				phy_interface_t interface);
+static inline ofnode phy_get_ofnode(struct phy_device *phydev)
+{
+	return ofnode_null();
+}
 #endif
 int phy_startup(struct phy_device *phydev);
 int phy_config(struct phy_device *phydev);