net: dsa: Add new binding implementation

The existing DSA binding has a number of limitations and problems. The
main problem is that it cannot represent a switch as a linux device,
hanging off some bus. It is limited to one CPU port. The DSA platform
device is artificial, and does not really represent hardware.

Implement a new binding which can be embedded into any type of node on
a bus to represent one switch device, and its links to other switches.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx.c

@@ -3748,6 +3748,12 @@ int mv88e6xxx_probe(struct mdio_device *mdiodev)
 
 	dev_set_drvdata(dev, ds);
 
+	err = dsa_register_switch(ds, mdiodev->dev.of_node);
+	if (err) {
+		mv88e6xxx_mdio_unregister(ps);
+		return err;
+	}
+
 	dev_info(dev, "switch 0x%x probed: %s, revision %u\n",
 		 prod_num, ps->info->name, rev);
 
@@ -3759,6 +3765,7 @@ static void mv88e6xxx_remove(struct mdio_device *mdiodev)
 	struct dsa_switch *ds = dev_get_drvdata(&mdiodev->dev);
 	struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
 
+	dsa_unregister_switch(ds);
 	put_device(&ps->bus->dev);
 
 	mv88e6xxx_mdio_unregister(ps);

include/net/dsa.h

@@ -85,6 +85,17 @@ struct dsa_platform_data {
 struct packet_type;
 
 struct dsa_switch_tree {
+	struct list_head	list;
+
+	/* Tree identifier */
+	u32 tree;
+
+	/* Number of switches attached to this tree */
+	struct kref refcount;
+
+	/* Has this tree been applied to the hardware? */
+	bool applied;
+
 	/*
 	 * Configuration data for the platform device that owns
 	 * this dsa switch tree instance.
@@ -169,10 +180,16 @@ struct dsa_switch {
 	struct device		*hwmon_dev;
 #endif
 
+	/*
+	 * The lower device this switch uses to talk to the host
+	 */
+	struct net_device *master_netdev;
+
 	/*
 	 * Slave mii_bus and devices for the individual ports.
 	 */
 	u32			dsa_port_mask;
+	u32			cpu_port_mask;
 	u32			enabled_port_mask;
 	u32			phys_mii_mask;
 	struct dsa_port		ports[DSA_MAX_PORTS];
@@ -361,4 +378,7 @@ static inline bool dsa_uses_tagged_protocol(struct dsa_switch_tree *dst)
 {
 	return dst->rcv != NULL;
 }
+
+void dsa_unregister_switch(struct dsa_switch *ds);
+int dsa_register_switch(struct dsa_switch *ds, struct device_node *np);
 #endif

net/dsa/Makefile

 # the core
 obj-$(CONFIG_NET_DSA) += dsa_core.o
-dsa_core-y += dsa.o slave.o
+dsa_core-y += dsa.o slave.o dsa2.o
 
 # tagging formats
 dsa_core-$(CONFIG_NET_DSA_TAG_BRCM) += tag_brcm.o

net/dsa/dsa.c

@@ -294,6 +294,7 @@ static int dsa_switch_setup_one(struct dsa_switch *ds, struct device *parent)
 			}
 			dst->cpu_switch = index;
 			dst->cpu_port = i;
+			ds->cpu_port_mask |= 1 << i;
 		} else if (!strcmp(name, "dsa")) {
 			ds->dsa_port_mask |= 1 << i;
 		} else {
@@ -492,6 +493,10 @@ static void dsa_switch_destroy(struct dsa_switch *ds)
 		if (!(dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port)))
 			continue;
 		dsa_cpu_dsa_destroy(ds->ports[port].dn);
+
+		/* Clearing a bit which is not set does no harm */
+		ds->cpu_port_mask |= ~(1 << port);
+		ds->dsa_port_mask |= ~(1 << port);
 	}
 
 	if (ds->slave_mii_bus && ds->drv->phy_read)

net/dsa/dsa_priv.h

@@ -59,7 +59,7 @@ const struct dsa_device_ops *dsa_resolve_tag_protocol(int tag_protocol);
 extern const struct dsa_device_ops notag_netdev_ops;
 void dsa_slave_mii_bus_init(struct dsa_switch *ds);
 int dsa_slave_create(struct dsa_switch *ds, struct device *parent,
-		     int port, char *name);
+		     int port, const char *name);
 void dsa_slave_destroy(struct net_device *slave_dev);
 int dsa_slave_suspend(struct net_device *slave_dev);
 int dsa_slave_resume(struct net_device *slave_dev);

net/dsa/slave.c

@@ -1099,14 +1099,18 @@ int dsa_slave_resume(struct net_device *slave_dev)
 }
 
 int dsa_slave_create(struct dsa_switch *ds, struct device *parent,
-		     int port, char *name)
+		     int port, const char *name)
 {
-	struct net_device *master = ds->dst->master_netdev;
 	struct dsa_switch_tree *dst = ds->dst;
+	struct net_device *master;
 	struct net_device *slave_dev;
 	struct dsa_slave_priv *p;
 	int ret;
 
+	master = ds->dst->master_netdev;
+	if (ds->master_netdev)
+		master = ds->master_netdev;
+
 	slave_dev = alloc_netdev(sizeof(struct dsa_slave_priv), name,
 				 NET_NAME_UNKNOWN, ether_setup);
 	if (slave_dev == NULL)