[net-next PATCH v6 02/10] net: phy: add support for scanning PHY in PHY packages nodes

[Christian Marangi <ansuelsmth@gmail.com>]

Add support for scanning PHY in PHY package nodes. PHY packages nodes
are just container for actual PHY on the MDIO bus.

Their PHY address defined in the PHY package node are absolute and
reflect the address on the MDIO bus.

mdio_bus.c and of_mdio.c is updated to now support and parse also
PHY package subnode by checking if the node name match
"ethernet-phy-package".

As PHY package reg is mandatory and each PHY in the PHY package must
have a reg, every invalid PHY Package node is ignored and will be
skipped by the autoscan fallback.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
 drivers/net/mdio/of_mdio.c | 79 +++++++++++++++++++++++++++-----------
 drivers/net/phy/mdio_bus.c | 44 +++++++++++++++++----
 2 files changed, 92 insertions(+), 31 deletions(-)

diff --git a/drivers/net/mdio/of_mdio.c b/drivers/net/mdio/of_mdio.c
index 64ebcb6d235c..08e607f62e10 100644
--- a/drivers/net/mdio/of_mdio.c
+++ b/drivers/net/mdio/of_mdio.c
@@ -139,6 +139,53 @@ bool of_mdiobus_child_is_phy(struct device_node *child)
 }
 EXPORT_SYMBOL(of_mdiobus_child_is_phy);
 
+static int __of_mdiobus_parse_phys(struct mii_bus *mdio, struct device_node *np,
+				   bool *scanphys)
+{
+	struct device_node *child;
+	int addr, rc = 0;
+
+	/* Loop over the child nodes and register a phy_device for each phy */
+	for_each_available_child_of_node(np, child) {
+		if (of_node_name_eq(child, "ethernet-phy-package")) {
+			/* Ignore invalid ethernet-phy-package node */
+			if (!of_property_present(child, "reg"))
+				continue;
+
+			rc = __of_mdiobus_parse_phys(mdio, child, NULL);
+			if (rc && rc != -ENODEV)
+				goto exit;
+
+			continue;
+		}
+
+		addr = of_mdio_parse_addr(&mdio->dev, child);
+		if (addr < 0) {
+			/* Skip scanning for invalid ethernet-phy-package node */
+			if (scanphys)
+				*scanphys = true;
+			continue;
+		}
+
+		if (of_mdiobus_child_is_phy(child))
+			rc = of_mdiobus_register_phy(mdio, child, addr);
+		else
+			rc = of_mdiobus_register_device(mdio, child, addr);
+
+		if (rc == -ENODEV)
+			dev_err(&mdio->dev,
+				"MDIO device at address %d is missing.\n",
+				addr);
+		else if (rc)
+			goto exit;
+	}
+
+	return 0;
+exit:
+	of_node_put(child);
+	return rc;
+}
+
 /**
  * __of_mdiobus_register - Register mii_bus and create PHYs from the device tree
  * @mdio: pointer to mii_bus structure
@@ -180,33 +227,18 @@ int __of_mdiobus_register(struct mii_bus *mdio, struct device_node *np,
 		return rc;
 
 	/* Loop over the child nodes and register a phy_device for each phy */
-	for_each_available_child_of_node(np, child) {
-		addr = of_mdio_parse_addr(&mdio->dev, child);
-		if (addr < 0) {
-			scanphys = true;
-			continue;
-		}
-
-		if (of_mdiobus_child_is_phy(child))
-			rc = of_mdiobus_register_phy(mdio, child, addr);
-		else
-			rc = of_mdiobus_register_device(mdio, child, addr);
-
-		if (rc == -ENODEV)
-			dev_err(&mdio->dev,
-				"MDIO device at address %d is missing.\n",
-				addr);
-		else if (rc)
-			goto unregister;
-	}
+	rc = __of_mdiobus_parse_phys(mdio, np, &scanphys);
+	if (rc)
+		goto unregister;
 
 	if (!scanphys)
 		return 0;
 
 	/* auto scan for PHYs with empty reg property */
 	for_each_available_child_of_node(np, child) {
-		/* Skip PHYs with reg property set */
-		if (of_property_present(child, "reg"))
+		/* Skip PHYs with reg property set or ethernet-phy-package node */
+		if (of_property_present(child, "reg") ||
+		    of_node_name_eq(child, "ethernet-phy-package"))
 			continue;
 
 		for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
@@ -227,15 +259,16 @@ int __of_mdiobus_register(struct mii_bus *mdio, struct device_node *np,
 				if (!rc)
 					break;
 				if (rc != -ENODEV)
-					goto unregister;
+					goto put_unregister;
 			}
 		}
 	}
 
 	return 0;
 
-unregister:
+put_unregister:
 	of_node_put(child);
+unregister:
 	mdiobus_unregister(mdio);
 	return rc;
 }
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index afbad1ad8683..08624f073014 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -459,19 +459,34 @@ EXPORT_SYMBOL(of_mdio_find_bus);
  * found, set the of_node pointer for the mdio device. This allows
  * auto-probed phy devices to be supplied with information passed in
  * via DT.
+ * If a PHY package is found, PHY is searched also there.
  */
-static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
-				    struct mdio_device *mdiodev)
+static int of_mdiobus_find_phy(struct device *dev, struct mdio_device *mdiodev,
+			       struct device_node *np)
 {
-	struct device *dev = &mdiodev->dev;
 	struct device_node *child;
 
-	if (dev->of_node || !bus->dev.of_node)
-		return;
-
-	for_each_available_child_of_node(bus->dev.of_node, child) {
+	for_each_available_child_of_node(np, child) {
 		int addr;
 
+		if (of_node_name_eq(child, "ethernet-phy-package")) {
+			/* Validate PHY package reg presence */
+			if (!of_property_present(child, "reg")) {
+				of_node_put(child);
+				return -EINVAL;
+			}
+
+			if (!of_mdiobus_find_phy(dev, mdiodev, child)) {
+				/* The refcount for the PHY package will be
+				 * incremented later when PHY join the Package.
+				 */
+				of_node_put(child);
+				return 0;
+			}
+
+			continue;
+		}
+
 		addr = of_mdio_parse_addr(dev, child);
 		if (addr < 0)
 			continue;
@@ -481,9 +496,22 @@ static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
 			/* The refcount on "child" is passed to the mdio
 			 * device. Do _not_ use of_node_put(child) here.
 			 */
-			return;
+			return 0;
 		}
 	}
+
+	return -ENODEV;
+}
+
+static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
+				    struct mdio_device *mdiodev)
+{
+	struct device *dev = &mdiodev->dev;
+
+	if (dev->of_node || !bus->dev.of_node)
+		return;
+
+	of_mdiobus_find_phy(dev, mdiodev, bus->dev.of_node);
 }
 #else /* !IS_ENABLED(CONFIG_OF_MDIO) */
 static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
-- 
2.43.0