net: bcmgenet: add support for ethtool flow control

This commit extends the supported ethtool operations to allow MAC
level flow control to be configured for the bcmgenet driver.

The ethtool utility can be used to change the configuration of
auto-negotiated symmetric and asymmetric modes as well as manually
configuring support for RX and TX Pause frames individually.
Signed-off-by: Doug Berger <opendmb@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/genet/bcmgenet.c

@@ -935,6 +935,48 @@ static int bcmgenet_set_coalesce(struct net_device *dev,
 	return 0;
 }
 
+static void bcmgenet_get_pauseparam(struct net_device *dev,
+				    struct ethtool_pauseparam *epause)
+{
+	struct bcmgenet_priv *priv;
+	u32 umac_cmd;
+
+	priv = netdev_priv(dev);
+
+	epause->autoneg = priv->autoneg_pause;
+
+	if (netif_carrier_ok(dev)) {
+		/* report active state when link is up */
+		umac_cmd = bcmgenet_umac_readl(priv, UMAC_CMD);
+		epause->tx_pause = !(umac_cmd & CMD_TX_PAUSE_IGNORE);
+		epause->rx_pause = !(umac_cmd & CMD_RX_PAUSE_IGNORE);
+	} else {
+		/* otherwise report stored settings */
+		epause->tx_pause = priv->tx_pause;
+		epause->rx_pause = priv->rx_pause;
+	}
+}
+
+static int bcmgenet_set_pauseparam(struct net_device *dev,
+				   struct ethtool_pauseparam *epause)
+{
+	struct bcmgenet_priv *priv = netdev_priv(dev);
+
+	if (!dev->phydev)
+		return -ENODEV;
+
+	if (!phy_validate_pause(dev->phydev, epause))
+		return -EINVAL;
+
+	priv->autoneg_pause = !!epause->autoneg;
+	priv->tx_pause = !!epause->tx_pause;
+	priv->rx_pause = !!epause->rx_pause;
+
+	bcmgenet_phy_pause_set(dev, priv->rx_pause, priv->tx_pause);
+
+	return 0;
+}
+
 /* standard ethtool support functions. */
 enum bcmgenet_stat_type {
 	BCMGENET_STAT_NETDEV = -1,
@@ -1587,6 +1629,8 @@ static const struct ethtool_ops bcmgenet_ethtool_ops = {
 	.get_ts_info		= ethtool_op_get_ts_info,
 	.get_rxnfc		= bcmgenet_get_rxnfc,
 	.set_rxnfc		= bcmgenet_set_rxnfc,
+	.get_pauseparam		= bcmgenet_get_pauseparam,
+	.set_pauseparam		= bcmgenet_set_pauseparam,
 };
 
 /* Power down the unimac, based on mode. */
@@ -3364,6 +3408,8 @@ static int bcmgenet_open(struct net_device *dev)
 		goto err_irq1;
 	}
 
+	bcmgenet_phy_pause_set(dev, priv->rx_pause, priv->tx_pause);
+
 	bcmgenet_netif_start(dev);
 
 	netif_tx_start_all_queues(dev);
@@ -3945,6 +3991,11 @@ static int bcmgenet_probe(struct platform_device *pdev)
 
 	spin_lock_init(&priv->lock);
 
+	/* Set default pause parameters */
+	priv->autoneg_pause = 1;
+	priv->tx_pause = 1;
+	priv->rx_pause = 1;
+
 	SET_NETDEV_DEV(dev, &pdev->dev);
 	dev_set_drvdata(&pdev->dev, dev);
 	dev->watchdog_timeo = 2 * HZ;

drivers/net/ethernet/broadcom/genet/bcmgenet.h

@@ -594,6 +594,9 @@ struct bcmgenet_priv {
 
 	/* other misc variables */
 	struct bcmgenet_hw_params *hw_params;
+	unsigned autoneg_pause:1;
+	unsigned tx_pause:1;
+	unsigned rx_pause:1;
 
 	/* MDIO bus variables */
 	wait_queue_head_t wq;
@@ -686,6 +689,7 @@ int bcmgenet_mii_init(struct net_device *dev);
 int bcmgenet_mii_config(struct net_device *dev, bool init);
 int bcmgenet_mii_probe(struct net_device *dev);
 void bcmgenet_mii_exit(struct net_device *dev);
+void bcmgenet_phy_pause_set(struct net_device *dev, bool rx, bool tx);
 void bcmgenet_phy_power_set(struct net_device *dev, bool enable);
 void bcmgenet_mii_setup(struct net_device *dev);
 

drivers/net/ethernet/broadcom/genet/bcmmii.c

@@ -41,12 +41,29 @@ static void bcmgenet_mac_config(struct net_device *dev)
 	cmd_bits <<= CMD_SPEED_SHIFT;
 
 	/* duplex */
-	if (phydev->duplex != DUPLEX_FULL)
-		cmd_bits |= CMD_HD_EN;
+	if (phydev->duplex != DUPLEX_FULL) {
+		cmd_bits |= CMD_HD_EN |
+			CMD_RX_PAUSE_IGNORE | CMD_TX_PAUSE_IGNORE;
+	} else {
+		/* pause capability defaults to Symmetric */
+		if (priv->autoneg_pause) {
+			bool tx_pause = 0, rx_pause = 0;
+
+			if (phydev->autoneg)
+				phy_get_pause(phydev, &tx_pause, &rx_pause);
 
-	/* pause capability */
-	if (!phydev->pause)
-		cmd_bits |= CMD_RX_PAUSE_IGNORE | CMD_TX_PAUSE_IGNORE;
+			if (!tx_pause)
+				cmd_bits |= CMD_TX_PAUSE_IGNORE;
+			if (!rx_pause)
+				cmd_bits |= CMD_RX_PAUSE_IGNORE;
+		}
+
+		/* Manual override */
+		if (!priv->rx_pause)
+			cmd_bits |= CMD_RX_PAUSE_IGNORE;
+		if (!priv->tx_pause)
+			cmd_bits |= CMD_TX_PAUSE_IGNORE;
+	}
 
 	/* Program UMAC and RGMII block based on established
 	 * link speed, duplex, and pause. The speed set in
@@ -101,6 +118,21 @@ static int bcmgenet_fixed_phy_link_update(struct net_device *dev,
 	return 0;
 }
 
+void bcmgenet_phy_pause_set(struct net_device *dev, bool rx, bool tx)
+{
+	struct phy_device *phydev = dev->phydev;
+
+	linkmode_mod_bit(ETHTOOL_LINK_MODE_Pause_BIT, phydev->advertising, rx);
+	linkmode_mod_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT, phydev->advertising,
+			 rx | tx);
+	phy_start_aneg(phydev);
+
+	mutex_lock(&phydev->lock);
+	if (phydev->link)
+		bcmgenet_mac_config(dev);
+	mutex_unlock(&phydev->lock);
+}
+
 void bcmgenet_phy_power_set(struct net_device *dev, bool enable)
 {
 	struct bcmgenet_priv *priv = netdev_priv(dev);
@@ -351,8 +383,6 @@ int bcmgenet_mii_probe(struct net_device *dev)
 		return ret;
 	}
 
-	linkmode_copy(phydev->advertising, phydev->supported);
-
 	/* The internal PHY has its link interrupts routed to the
 	 * Ethernet MAC ISRs. On GENETv5 there is a hardware issue
 	 * that prevents the signaling of link UP interrupts when