net: dsa: Allow multi hop routes to be expressed

With more than two switches in a hierarchy, it becomes necessary to
describe multi-hop routes between switches. The current binding does
not allow this, although the older platform_data did. Extend the link
property to be a list rather than a single phandle to a remote switch.
It is then possible to express that a port should be used to reach
more than one switch and the switch maybe more than one hop away.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 30 insertions, 10 deletions

diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
index 78d4ac9..053eb2b 100644
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -554,6 +554,31 @@ static int dsa_of_setup_routing_table(struct dsa_platform_data *pd,
 	return 0;
 }
 
+static int dsa_of_probe_links(struct dsa_platform_data *pd,
+			      struct dsa_chip_data *cd,
+			      int chip_index, int port_index,
+			      struct device_node *port,
+			      const char *port_name)
+{
+	struct device_node *link;
+	int link_index;
+	int ret;
+
+	for (link_index = 0;; link_index++) {
+		link = of_parse_phandle(port, "link", link_index);
+		if (!link)
+			break;
+
+		if (!strcmp(port_name, "dsa") && pd->nr_chips > 1) {
+			ret = dsa_of_setup_routing_table(pd, cd, chip_index,
+							 port_index, link);
+			if (ret)
+				return ret;
+		}
+	}
+	return 0;
+}
+
 static void dsa_of_free_platform_data(struct dsa_platform_data *pd)
 {
 	int i;
@@ -573,7 +598,7 @@ static void dsa_of_free_platform_data(struct dsa_platform_data *pd)
 static int dsa_of_probe(struct device *dev)
 {
 	struct device_node *np = dev->of_node;
-	struct device_node *child, *mdio, *ethernet, *port, *link;
+	struct device_node *child, *mdio, *ethernet, *port;
 	struct mii_bus *mdio_bus, *mdio_bus_switch;
 	struct net_device *ethernet_dev;
 	struct dsa_platform_data *pd;
@@ -668,15 +693,10 @@ static int dsa_of_probe(struct device *dev)
 				goto out_free_chip;
 			}
 
-			link = of_parse_phandle(port, "link", 0);
-
-			if (!strcmp(port_name, "dsa") && link &&
-					pd->nr_chips > 1) {
-				ret = dsa_of_setup_routing_table(pd, cd,
-						chip_index, port_index, link);
-				if (ret)
-					goto out_free_chip;
-			}
+			ret = dsa_of_probe_links(pd, cd, chip_index,
+						 port_index, port, port_name);
+			if (ret)
+				goto out_free_chip;
 
 		}
 	}