net: dsa: mv88e6xxx: Refactor MDIO so driver registers mdio bus

Have the switch driver register its own MDIO bus. This allows for an
mdio property in the device tree, with child nodes for phys, which
can be referenced via phandles, etc.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/dsa/mv88e6xxx.c b/drivers/net/dsa/mv88e6xxx.c
index b8e65e6..192b39c 100644
--- a/drivers/net/dsa/mv88e6xxx.c
+++ b/drivers/net/dsa/mv88e6xxx.c
@@ -21,6 +21,7 @@
 #include <linux/list.h>
 #include <linux/mdio.h>
 #include <linux/module.h>
+#include <linux/of_mdio.h>
 #include <linux/netdevice.h>
 #include <linux/gpio/consumer.h>
 #include <linux/phy.h>
@@ -3130,13 +3131,11 @@
 	int i;
 
 	ps->ds = ds;
+	ds->slave_mii_bus = ps->mdio_bus;
 
 	if (mv88e6xxx_has(ps, MV88E6XXX_FLAG_EEPROM))
 		mutex_init(&ps->eeprom_mutex);
 
-	if (mv88e6xxx_has(ps, MV88E6XXX_FLAG_PPU))
-		mv88e6xxx_ppu_state_init(ps);
-
 	mutex_lock(&ps->smi_mutex);
 
 	err = mv88e6xxx_switch_reset(ps);
@@ -3192,9 +3191,9 @@
 	return -EINVAL;
 }
 
-static int mv88e6xxx_mdio_read(struct dsa_switch *ds, int port, int regnum)
+static int mv88e6xxx_mdio_read(struct mii_bus *bus, int port, int regnum)
 {
-	struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
+	struct mv88e6xxx_priv_state *ps = bus->priv;
 	int addr = mv88e6xxx_port_to_mdio_addr(ps, port);
 	int ret;
 
@@ -3214,10 +3213,10 @@
 	return ret;
 }
 
-static int mv88e6xxx_mdio_write(struct dsa_switch *ds, int port, int regnum,
+static int mv88e6xxx_mdio_write(struct mii_bus *bus, int port, int regnum,
 				u16 val)
 {
-	struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
+	struct mv88e6xxx_priv_state *ps = bus->priv;
 	int addr = mv88e6xxx_port_to_mdio_addr(ps, port);
 	int ret;
 
@@ -3237,6 +3236,66 @@
 	return ret;
 }
 
+static int mv88e6xxx_mdio_register(struct mv88e6xxx_priv_state *ps,
+				   struct device_node *np)
+{
+	static int index;
+	struct mii_bus *bus;
+	int err;
+
+	if (mv88e6xxx_has(ps, MV88E6XXX_FLAG_PPU))
+		mv88e6xxx_ppu_state_init(ps);
+
+	if (np)
+		ps->mdio_np = of_get_child_by_name(np, "mdio");
+
+	bus = devm_mdiobus_alloc(ps->dev);
+	if (!bus)
+		return -ENOMEM;
+
+	bus->priv = (void *)ps;
+	if (np) {
+		bus->name = np->full_name;
+		snprintf(bus->id, MII_BUS_ID_SIZE, "%s", np->full_name);
+	} else {
+		bus->name = "mv88e6xxx SMI";
+		snprintf(bus->id, MII_BUS_ID_SIZE, "mv88e6xxx-%d", index++);
+	}
+
+	bus->read = mv88e6xxx_mdio_read;
+	bus->write = mv88e6xxx_mdio_write;
+	bus->parent = ps->dev;
+
+	if (ps->mdio_np)
+		err = of_mdiobus_register(bus, ps->mdio_np);
+	else
+		err = mdiobus_register(bus);
+	if (err) {
+		dev_err(ps->dev, "Cannot register MDIO bus (%d)\n", err);
+		goto out;
+	}
+	ps->mdio_bus = bus;
+
+	return 0;
+
+out:
+	if (ps->mdio_np)
+		of_node_put(ps->mdio_np);
+
+	return err;
+}
+
+static void mv88e6xxx_mdio_unregister(struct mv88e6xxx_priv_state *ps)
+
+{
+	struct mii_bus *bus = ps->mdio_bus;
+
+	mdiobus_unregister(bus);
+
+	if (ps->mdio_np)
+		of_node_put(ps->mdio_np);
+}
+
 #ifdef CONFIG_NET_DSA_HWMON
 
 static int mv88e61xx_get_temp(struct dsa_switch *ds, int *temp)
@@ -3549,6 +3608,7 @@
 	struct mii_bus *bus;
 	const char *name;
 	int id, prod_num, rev;
+	int err;
 
 	bus = dsa_host_dev_to_mii_bus(host_dev);
 	if (!bus)
@@ -3575,8 +3635,13 @@
 	ps->bus = bus;
 	ps->sw_addr = sw_addr;
 	ps->info = info;
+	ps->dev = dsa_dev;
 	mutex_init(&ps->smi_mutex);
 
+	err = mv88e6xxx_mdio_register(ps, NULL);
+	if (err)
+		return NULL;
+
 	*priv = ps;
 
 	dev_info(&ps->bus->dev, "switch 0x%x probed: %s, revision %u\n",
@@ -3590,8 +3655,6 @@
 	.probe			= mv88e6xxx_drv_probe,
 	.setup			= mv88e6xxx_setup,
 	.set_addr		= mv88e6xxx_set_addr,
-	.phy_read		= mv88e6xxx_mdio_read,
-	.phy_write		= mv88e6xxx_mdio_write,
 	.adjust_link		= mv88e6xxx_adjust_link,
 	.get_strings		= mv88e6xxx_get_strings,
 	.get_ethtool_stats	= mv88e6xxx_get_ethtool_stats,
@@ -3677,6 +3740,12 @@
 	    !of_property_read_u32(np, "eeprom-length", &eeprom_len))
 		ps->eeprom_len = eeprom_len;
 
+	err = mv88e6xxx_mdio_register(ps, mdiodev->dev.of_node);
+	if (err)
+		return err;
+
+	ds->slave_mii_bus = ps->mdio_bus;
+
 	dev_set_drvdata(dev, ds);
 
 	dev_info(dev, "switch 0x%x probed: %s, revision %u\n",
@@ -3691,6 +3760,8 @@
 	struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
 
 	put_device(&ps->bus->dev);
+
+	mv88e6xxx_mdio_unregister(ps);
 }
 
 static const struct of_device_id mv88e6xxx_of_match[] = {