net: socionext: Stop PHY before resetting netsec

In ndo_stop, driver resets the netsec ethernet controller IP.
When the netsec IP is reset, HW running mode turns to NRM mode
and driver has to wait until this mode transition completes.

But mode transition to NRM will not complete if the PHY is
in normal operation state. Netsec IP requires PHY is in
power down state when it is reset.

This modification stops the PHY before resetting netsec.

Together with this modification, phy_addr is stored in netsec_priv
structure because ndev->phydev is not yet ready in ndo_init.

Fixes: 533dd11a ("net: socionext: Add Synquacer NetSec driver")
Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Signed-off-by: Yoshitoyo Osaki <osaki.yoshitoyo@socionext.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/socionext/netsec.c

@@ -274,6 +274,7 @@ struct netsec_priv {
 	struct clk *clk;
 	u32 msg_enable;
 	u32 freq;
+	u32 phy_addr;
 	bool rx_cksum_offload_flag;
 };
 
@@ -1343,11 +1344,11 @@ static int netsec_netdev_stop(struct net_device *ndev)
 	netsec_uninit_pkt_dring(priv, NETSEC_RING_TX);
 	netsec_uninit_pkt_dring(priv, NETSEC_RING_RX);
 
-	ret = netsec_reset_hardware(priv, false);
-
 	phy_stop(ndev->phydev);
 	phy_disconnect(ndev->phydev);
 
+	ret = netsec_reset_hardware(priv, false);
+
 	pm_runtime_put_sync(priv->dev);
 
 	return ret;
@@ -1357,6 +1358,7 @@ static int netsec_netdev_init(struct net_device *ndev)
 {
 	struct netsec_priv *priv = netdev_priv(ndev);
 	int ret;
+	u16 data;
 
 	ret = netsec_alloc_dring(priv, NETSEC_RING_TX);
 	if (ret)
@@ -1366,6 +1368,11 @@ static int netsec_netdev_init(struct net_device *ndev)
 	if (ret)
 		goto err1;
 
+	/* set phy power down */
+	data = netsec_phy_read(priv->mii_bus, priv->phy_addr, MII_BMCR) |
+		BMCR_PDOWN;
+	netsec_phy_write(priv->mii_bus, priv->phy_addr, MII_BMCR, data);
+
 	ret = netsec_reset_hardware(priv, true);
 	if (ret)
 		goto err2;
@@ -1415,7 +1422,7 @@ static const struct net_device_ops netsec_netdev_ops = {
 };
 
 static int netsec_of_probe(struct platform_device *pdev,
-			   struct netsec_priv *priv)
+			   struct netsec_priv *priv, u32 *phy_addr)
 {
 	priv->phy_np = of_parse_phandle(pdev->dev.of_node, "phy-handle", 0);
 	if (!priv->phy_np) {
@@ -1423,6 +1430,8 @@ static int netsec_of_probe(struct platform_device *pdev,
 		return -EINVAL;
 	}
 
+	*phy_addr = of_mdio_parse_addr(&pdev->dev, priv->phy_np);
+
 	priv->clk = devm_clk_get(&pdev->dev, NULL); /* get by 'phy_ref_clk' */
 	if (IS_ERR(priv->clk)) {
 		dev_err(&pdev->dev, "phy_ref_clk not found\n");
@@ -1623,12 +1632,14 @@ static int netsec_probe(struct platform_device *pdev)
 	}
 
 	if (dev_of_node(&pdev->dev))
-		ret = netsec_of_probe(pdev, priv);
+		ret = netsec_of_probe(pdev, priv, &phy_addr);
 	else
 		ret = netsec_acpi_probe(pdev, priv, &phy_addr);
 	if (ret)
 		goto free_ndev;
 
+	priv->phy_addr = phy_addr;
+
 	if (!priv->freq) {
 		dev_err(&pdev->dev, "missing PHY reference clock frequency\n");
 		ret = -ENODEV;