Merge branch 'dsa-multi-swtich'

Andrew Lunn says:

====================
D in DSA patches

The D in DSA is distributed, meaning multiple switches can be
connected together. Currently no mainline system does this, and so the
code is broken. This patchset contains two fixes, and a small helper.

With three of more switches, the current device tree binding is not
sufficient to express the routing between the switches. The first
patch extends the binding, in a backwards compatible way, to allow a
link between a switch to describe all the switches accessible over the
link, not just the direct neighbor.

The third patch fixes the port configuration on newer devices for
links connecting switches.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/dsa/dsa.txt

@@ -44,9 +44,10 @@ Note that a port labelled "dsa" will imply checking for the uplink phandle
 described below.
 
 Optionnal property:
-- link			: Should be a phandle to another switch's DSA port.
+- link			: Should be a list of phandles to another switch's DSA port.
 			  This property is only used when switches are being
-			  chained/cascaded together.
+			  chained/cascaded together. This port is used as outgoing port
+			  towards the phandle port, which can be more than one hop away.
 
 - phy-handle		: Phandle to a PHY on an external MDIO bus, not the
 			  switch internal one. See
@@ -100,10 +101,11 @@ Example:
 				label = "cpu";
 			};
 
-			switch0uplink: port@6 {
+			switch0port6: port@6 {
 				reg = <6>;
 				label = "dsa";
-				link = <&switch1uplink>;
+				link = <&switch1port0
+				        &switch2port0>;
 			};
 		};
 
@@ -113,10 +115,29 @@ Example:
 			reg = <17 1>;	/* MDIO address 17, switch 1 in tree */
 			mii-bus = <&mii_bus1>;
 
-			switch1uplink: port@0 {
+			switch1port0: port@0 {
 				reg = <0>;
 				label = "dsa";
-				link = <&switch0uplink>;
+				link = <&switch0port6>;
+			};
+			switch1port1: port@1 {
+				reg = <1>;
+				label = "dsa";
+				link = <&switch2port1>;
+			};
+		};
+
+		switch@2 {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			reg = <18 2>;	/* MDIO address 18, switch 2 in tree */
+			mii-bus = <&mii_bus1>;
+
+			switch2port0: port@0 {
+				reg = <0>;
+				label = "dsa";
+				link = <&switch1port1
+				        &switch0port6>;
 			};
 		};
 	};

drivers/net/dsa/mv88e6xxx.c

@@ -1926,8 +1926,7 @@ static int mv88e6xxx_setup_port(struct dsa_switch *ds, int port)
 		 * full duplex.
 		 */
 		reg = _mv88e6xxx_reg_read(ds, REG_PORT(port), PORT_PCS_CTRL);
-		if (dsa_is_cpu_port(ds, port) ||
-		    ds->dsa_port_mask & (1 << port)) {
+		if (dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port)) {
 			reg |= PORT_PCS_CTRL_FORCE_LINK |
 				PORT_PCS_CTRL_LINK_UP |
 				PORT_PCS_CTRL_DUPLEX_FULL |
@@ -1988,12 +1987,15 @@ static int mv88e6xxx_setup_port(struct dsa_switch *ds, int port)
 				reg |= PORT_CONTROL_EGRESS_ADD_TAG;
 		}
 	}
+	if (dsa_is_dsa_port(ds, port)) {
+		if (mv88e6xxx_6095_family(ds) || mv88e6xxx_6185_family(ds))
+			reg |= PORT_CONTROL_DSA_TAG;
 		if (mv88e6xxx_6352_family(ds) || mv88e6xxx_6351_family(ds) ||
 		    mv88e6xxx_6165_family(ds) || mv88e6xxx_6097_family(ds) ||
-	    mv88e6xxx_6095_family(ds) || mv88e6xxx_6065_family(ds) ||
 		    mv88e6xxx_6320_family(ds)) {
-		if (ds->dsa_port_mask & (1 << port))
 			reg |= PORT_CONTROL_FRAME_MODE_DSA;
+		}
+
 		if (port == dsa_upstream_port(ds))
 			reg |= PORT_CONTROL_FORWARD_UNKNOWN |
 				PORT_CONTROL_FORWARD_UNKNOWN_MC;

include/net/dsa.h

@@ -171,6 +171,11 @@ static inline bool dsa_is_cpu_port(struct dsa_switch *ds, int p)
 	return !!(ds->index == ds->dst->cpu_switch && p == ds->dst->cpu_port);
 }
 
+static inline bool dsa_is_dsa_port(struct dsa_switch *ds, int p)
+{
+	return !!((ds->dsa_port_mask) & (1 << p));
+}
+
 static inline bool dsa_is_port_initialized(struct dsa_switch *ds, int p)
 {
 	return ds->phys_port_mask & (1 << p) && ds->ports[p];

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);
+			ret = dsa_of_probe_links(pd, cd, chip_index,
+						 port_index, port, port_name);
 			if (ret)
 				goto out_free_chip;
-			}
 
 		}
 	}