b44: add phylib support

Most of the older home routers based on the Broadcom BCM47XX SoC series
are using a MAC that is supported by b44. On most of these routers not
the internal PHY of this MAC core is used, but a switch sometimes on an
external chip or integrated into the same SoC as the Ethernet core.
For this switch a special PHY driver is needed which should not be
integrated into b44 as the same switches are also used by other
Broadcom home networking SoCs which are using different Ethernet MAC
drivers. This was tested with the b53 switch driver which is currently
on its way to mainline.

If the internal PHY is not used, b44 will now search on the MDIO bus
for a phy and use the Linux phylib subsystem to register a driver.
Support for the internal PHY must stay here, because there are some
device which are suing the internal phy.

With this patch we scan the mdio bus when the sprom or nvram says that
the PHY address is 30, if a PHY was found at this address b44 uses it.

This was tested with a BCM4704, BCM4712 and BCM5354.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/Kconfig

@@ -23,6 +23,7 @@ config B44
 	depends on SSB_POSSIBLE && HAS_DMA
 	select SSB
 	select MII
+	select PHYLIB
 	---help---
 	  If you have a network (Ethernet) controller of this type, say Y
 	  or M and read the Ethernet-HOWTO, available from

drivers/net/ethernet/broadcom/b44.c

@@ -6,6 +6,7 @@
  * Copyright (C) 2006 Felix Fietkau (nbd@openwrt.org)
  * Copyright (C) 2006 Broadcom Corporation.
  * Copyright (C) 2007 Michael Buesch <m@bues.ch>
+ * Copyright (C) 2013 Hauke Mehrtens <hauke@hauke-m.de>
  *
  * Distribute under GPL.
  */
@@ -29,6 +30,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/ssb/ssb.h>
 #include <linux/slab.h>
+#include <linux/phy.h>
 
 #include <asm/uaccess.h>
 #include <asm/io.h>
@@ -316,6 +318,23 @@ static void b44_mdio_write_mii(struct net_device *dev, int phy_id, int location,
 	__b44_writephy(bp, phy_id, location, val);
 }
 
+static int b44_mdio_read_phylib(struct mii_bus *bus, int phy_id, int location)
+{
+	u32 val;
+	struct b44 *bp = bus->priv;
+	int rc = __b44_readphy(bp, phy_id, location, &val);
+	if (rc)
+		return 0xffffffff;
+	return val;
+}
+
+static int b44_mdio_write_phylib(struct mii_bus *bus, int phy_id, int location,
+				 u16 val)
+{
+	struct b44 *bp = bus->priv;
+	return __b44_writephy(bp, phy_id, location, val);
+}
+
 static int b44_phy_reset(struct b44 *bp)
 {
 	u32 val;
@@ -523,10 +542,12 @@ static void b44_check_phy(struct b44 *bp)
 
 	if (bp->flags & B44_FLAG_EXTERNAL_PHY) {
 		bp->flags |= B44_FLAG_100_BASE_T;
-		bp->flags |= B44_FLAG_FULL_DUPLEX;
 		if (!netif_carrier_ok(bp->dev)) {
 			u32 val = br32(bp, B44_TX_CTRL);
-			val |= TX_CTRL_DUPLEX;
+			if (bp->flags & B44_FLAG_FULL_DUPLEX)
+				val |= TX_CTRL_DUPLEX;
+			else
+				val &= ~TX_CTRL_DUPLEX;
 			bw32(bp, B44_TX_CTRL, val);
 			netif_carrier_on(bp->dev);
 			b44_link_report(bp);
@@ -1805,6 +1826,11 @@ static int b44_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 {
 	struct b44 *bp = netdev_priv(dev);
 
+	if (bp->flags & B44_FLAG_EXTERNAL_PHY) {
+		BUG_ON(!bp->phydev);
+		return phy_ethtool_gset(bp->phydev, cmd);
+	}
+
 	cmd->supported = (SUPPORTED_Autoneg);
 	cmd->supported |= (SUPPORTED_100baseT_Half |
 			  SUPPORTED_100baseT_Full |
@@ -1846,7 +1872,23 @@ static int b44_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 static int b44_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 {
 	struct b44 *bp = netdev_priv(dev);
-	u32 speed = ethtool_cmd_speed(cmd);
+	u32 speed;
+	int ret;
+
+	if (bp->flags & B44_FLAG_EXTERNAL_PHY) {
+		BUG_ON(!bp->phydev);
+		spin_lock_irq(&bp->lock);
+		if (netif_running(dev))
+			b44_setup_phy(bp);
+
+		ret = phy_ethtool_sset(bp->phydev, cmd);
+
+		spin_unlock_irq(&bp->lock);
+
+		return ret;
+	}
+
+	speed = ethtool_cmd_speed(cmd);
 
 	/* We do not support gigabit. */
 	if (cmd->autoneg == AUTONEG_ENABLE) {
@@ -2076,7 +2118,6 @@ static const struct ethtool_ops b44_ethtool_ops = {
 
 static int b44_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 {
-	struct mii_ioctl_data *data = if_mii(ifr);
 	struct b44 *bp = netdev_priv(dev);
 	int err = -EINVAL;
 
@@ -2084,7 +2125,12 @@ static int b44_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 		goto out;
 
 	spin_lock_irq(&bp->lock);
-	err = generic_mii_ioctl(&bp->mii_if, data, cmd, NULL);
+	if (bp->flags & B44_FLAG_EXTERNAL_PHY) {
+		BUG_ON(!bp->phydev);
+		err = phy_mii_ioctl(bp->phydev, ifr, cmd);
+	} else {
+		err = generic_mii_ioctl(&bp->mii_if, if_mii(ifr), cmd, NULL);
+	}
 	spin_unlock_irq(&bp->lock);
 out:
 	return err;
@@ -2146,6 +2192,127 @@ static const struct net_device_ops b44_netdev_ops = {
 #endif
 };
 
+static void b44_adjust_link(struct net_device *dev)
+{
+	struct b44 *bp = netdev_priv(dev);
+	struct phy_device *phydev = bp->phydev;
+	bool status_changed = 0;
+
+	BUG_ON(!phydev);
+
+	if (bp->old_link != phydev->link) {
+		status_changed = 1;
+		bp->old_link = phydev->link;
+	}
+
+	/* reflect duplex change */
+	if (phydev->link) {
+		if ((phydev->duplex == DUPLEX_HALF) &&
+		    (bp->flags & B44_FLAG_FULL_DUPLEX)) {
+			status_changed = 1;
+			bp->flags &= ~B44_FLAG_FULL_DUPLEX;
+		} else if ((phydev->duplex == DUPLEX_FULL) &&
+			   !(bp->flags & B44_FLAG_FULL_DUPLEX)) {
+			status_changed = 1;
+			bp->flags |= B44_FLAG_FULL_DUPLEX;
+		}
+	}
+
+	if (status_changed) {
+		b44_check_phy(bp);
+		phy_print_status(phydev);
+	}
+}
+
+static int b44_register_phy_one(struct b44 *bp)
+{
+	struct mii_bus *mii_bus;
+	struct ssb_device *sdev = bp->sdev;
+	struct phy_device *phydev;
+	char bus_id[MII_BUS_ID_SIZE + 3];
+	int err;
+
+	mii_bus = mdiobus_alloc();
+	if (!mii_bus) {
+		dev_err(sdev->dev, "mdiobus_alloc() failed\n");
+		err = -ENOMEM;
+		goto err_out;
+	}
+
+	mii_bus->priv = bp;
+	mii_bus->read = b44_mdio_read_phylib;
+	mii_bus->write = b44_mdio_write_phylib;
+	mii_bus->name = "b44_eth_mii";
+	mii_bus->parent = sdev->dev;
+	mii_bus->phy_mask = ~(1 << bp->phy_addr);
+	snprintf(mii_bus->id, MII_BUS_ID_SIZE, "%x", instance);
+	mii_bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
+	if (!mii_bus->irq) {
+		dev_err(sdev->dev, "mii_bus irq allocation failed\n");
+		err = -ENOMEM;
+		goto err_out_mdiobus;
+	}
+
+	memset(mii_bus->irq, PHY_POLL, sizeof(int) * PHY_MAX_ADDR);
+
+	bp->mii_bus = mii_bus;
+
+	err = mdiobus_register(mii_bus);
+	if (err) {
+		dev_err(sdev->dev, "failed to register MII bus\n");
+		goto err_out_mdiobus_irq;
+	}
+
+	snprintf(bus_id, sizeof(bus_id), PHY_ID_FMT, mii_bus->id, bp->phy_addr);
+
+	phydev = phy_connect(bp->dev, bus_id, &b44_adjust_link,
+			     PHY_INTERFACE_MODE_MII);
+	if (IS_ERR(phydev)) {
+		dev_err(sdev->dev, "could not attach PHY at %i\n",
+			bp->phy_addr);
+		err = PTR_ERR(phydev);
+		goto err_out_mdiobus_unregister;
+	}
+
+	/* mask with MAC supported features */
+	phydev->supported &= (SUPPORTED_100baseT_Half |
+			      SUPPORTED_100baseT_Full |
+			      SUPPORTED_Autoneg |
+			      SUPPORTED_MII);
+	phydev->advertising = phydev->supported;
+
+	bp->phydev = phydev;
+	bp->old_link = 0;
+	bp->phy_addr = phydev->addr;
+
+	dev_info(sdev->dev, "attached PHY driver [%s] (mii_bus:phy_addr=%s)\n",
+		 phydev->drv->name, dev_name(&phydev->dev));
+
+	return 0;
+
+err_out_mdiobus_unregister:
+	mdiobus_unregister(mii_bus);
+
+err_out_mdiobus_irq:
+	kfree(mii_bus->irq);
+
+err_out_mdiobus:
+	mdiobus_free(mii_bus);
+
+err_out:
+	return err;
+}
+
+static void b44_unregister_phy_one(struct b44 *bp)
+{
+	struct mii_bus *mii_bus = bp->mii_bus;
+
+	phy_disconnect(bp->phydev);
+	mdiobus_unregister(mii_bus);
+	kfree(mii_bus->irq);
+	mdiobus_free(mii_bus);
+}
+
 static int b44_init_one(struct ssb_device *sdev,
 			const struct ssb_device_id *ent)
 {
@@ -2245,10 +2412,20 @@ static int b44_init_one(struct ssb_device *sdev,
 	if (b44_phy_reset(bp) < 0)
 		bp->phy_addr = B44_PHY_ADDR_NO_LOCAL_PHY;
 
+	if (bp->flags & B44_FLAG_EXTERNAL_PHY) {
+		err = b44_register_phy_one(bp);
+		if (err) {
+			dev_err(sdev->dev, "Cannot register PHY, aborting\n");
+			goto err_out_unregister_netdev;
+		}
+	}
+
 	netdev_info(dev, "%s %pM\n", DRV_DESCRIPTION, dev->dev_addr);
 
 	return 0;
 
+err_out_unregister_netdev:
+	unregister_netdev(dev);
 err_out_powerdown:
 	ssb_bus_may_powerdown(sdev->bus);
 
@@ -2262,8 +2439,11 @@ static int b44_init_one(struct ssb_device *sdev,
 static void b44_remove_one(struct ssb_device *sdev)
 {
 	struct net_device *dev = ssb_get_drvdata(sdev);
+	struct b44 *bp = netdev_priv(dev);
 
 	unregister_netdev(dev);
+	if (bp->flags & B44_FLAG_EXTERNAL_PHY)
+		b44_unregister_phy_one(bp);
 	ssb_device_disable(sdev, 0);
 	ssb_bus_may_powerdown(sdev->bus);
 	free_netdev(dev);

drivers/net/ethernet/broadcom/b44.h

@@ -397,6 +397,9 @@ struct b44 {
 	u32			tx_pending;
 	u8			phy_addr;
 	u8			force_copybreak;
+	struct phy_device	*phydev;
+	struct mii_bus		*mii_bus;
+	int			old_link;
 	struct mii_if_info	mii_if;
 };