net: mvpp2: enable using phylink with ACPI

Now that the MDIO and phylink are supported in the ACPI
world, enable to use them in the mvpp2 driver. Ensure a backward
compatibility with the firmware whose ACPI description does
not contain the necessary elements for the proper phy handling
and fall back to relying on the link interrupts instead.
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c

@@ -4793,9 +4793,8 @@ static int mvpp2_open(struct net_device *dev)
 		goto err_cleanup_txqs;
 	}
 
-	/* Phylink isn't supported yet in ACPI mode */
-	if (port->of_node) {
-		err = phylink_of_phy_connect(port->phylink, port->of_node, 0);
+	if (port->phylink) {
+		err = phylink_fwnode_phy_connect(port->phylink, port->fwnode, 0);
 		if (err) {
 			netdev_err(port->dev, "could not attach PHY (%d)\n",
 				   err);
@@ -6703,6 +6702,19 @@ static void mvpp2_acpi_start(struct mvpp2_port *port)
 			  SPEED_UNKNOWN, DUPLEX_UNKNOWN, false, false);
 }
 
+/* In order to ensure backward compatibility for ACPI, check if the port
+ * firmware node comprises the necessary description allowing to use phylink.
+ */
+static bool mvpp2_use_acpi_compat_mode(struct fwnode_handle *port_fwnode)
+{
+	if (!is_acpi_node(port_fwnode))
+		return false;
+
+	return (!fwnode_property_present(port_fwnode, "phy-handle") &&
+		!fwnode_property_present(port_fwnode, "managed") &&
+		!fwnode_get_named_child_node(port_fwnode, "fixed-link"));
+}
+
 /* Ports initialization */
 static int mvpp2_port_probe(struct platform_device *pdev,
 			    struct fwnode_handle *port_fwnode,
@@ -6921,8 +6933,7 @@ static int mvpp2_port_probe(struct platform_device *pdev,
 	dev->max_mtu = MVPP2_BM_JUMBO_PKT_SIZE;
 	dev->dev.of_node = port_node;
 
-	/* Phylink isn't used w/ ACPI as of now */
-	if (port_node) {
+	if (!mvpp2_use_acpi_compat_mode(port_fwnode)) {
 		port->phylink_config.dev = &dev->dev;
 		port->phylink_config.type = PHYLINK_NETDEV;
 
@@ -6934,6 +6945,7 @@ static int mvpp2_port_probe(struct platform_device *pdev,
 		}
 		port->phylink = phylink;
 	} else {
+		dev_warn(&pdev->dev, "Use link irqs for port#%d. FW update required\n", port->id);
 		port->phylink = NULL;
 	}