openwrt/target/linux/ath25/patches-5.15/220-enet_micrel_workaround.patch

--- a/drivers/net/ethernet/atheros/ar231x/ar231x.c
+++ b/drivers/net/ethernet/atheros/ar231x/ar231x.c
@@ -133,6 +133,7 @@ static int ar231x_mdiobus_write(struct m
 static int ar231x_mdiobus_reset(struct mii_bus *bus);
 static int ar231x_mdiobus_probe(struct net_device *dev);
 static void ar231x_adjust_link(struct net_device *dev);
+static bool no_phy;
 
 #ifndef ERR
 #define ERR(fmt, args...) printk("%s: " fmt, __func__, ##args)
@@ -164,6 +165,32 @@ static const struct net_device_ops ar231
 #endif
 };
 
+static int get_phy_id(struct mii_bus *bus, int addr, u32 *phy_id)
+{
+	int phy_reg;
+
+	/**
+	 * Grab the bits from PHYIR1, and put them
+	 * in the upper half.
+	 */
+	phy_reg = mdiobus_read(bus, addr, MII_PHYSID1);
+
+	if (phy_reg < 0)
+		return -EIO;
+
+	*phy_id = (phy_reg & 0xffff) << 16;
+
+	/* Grab the bits from PHYIR2, and put them in the lower half */
+	phy_reg = mdiobus_read(bus, addr, MII_PHYSID2);
+
+	if (phy_reg < 0)
+		return -EIO;
+
+	*phy_id |= (phy_reg & 0xffff);
+
+	return 0;
+}
+
 static int ar231x_probe(struct platform_device *pdev)
 {
 	struct net_device *dev;
@@ -271,6 +298,24 @@ static int ar231x_probe(struct platform_
 
 	mdiobus_register(sp->mii_bus);
 
+	/**
+	 * Workaround for Micrel switch, which is only available on
+	 * one PHY and cannot be configured through MDIO.
+	 */
+	if (!no_phy) {
+		u32 phy_id = 0;
+
+		get_phy_id(sp->mii_bus, 1, &phy_id);
+		if (phy_id == 0x00221450)
+			no_phy = true;
+	}
+	if (no_phy) {
+		sp->link = 1;
+		netif_carrier_on(dev);
+		return 0;
+	}
+	no_phy = true;
+
 	if (ar231x_mdiobus_probe(dev) != 0) {
 		printk(KERN_ERR "%s: mdiobus_probe failed\n", dev->name);
 		rx_tasklet_cleanup(dev);
@@ -324,8 +369,10 @@ static int ar231x_remove(struct platform
 	rx_tasklet_cleanup(dev);
 	ar231x_init_cleanup(dev);
 	unregister_netdev(dev);
-	mdiobus_unregister(sp->mii_bus);
-	mdiobus_free(sp->mii_bus);
+	if (sp->mii_bus) {
+		mdiobus_unregister(sp->mii_bus);
+		mdiobus_free(sp->mii_bus);
+	}
 	kfree(dev);
 	return 0;
 }
@@ -868,7 +915,8 @@ static int ar231x_open(struct net_device
 
 	sp->eth_regs->mac_control |= MAC_CONTROL_RE;
 
-	phy_start(sp->phy_dev);
+	if (sp->phy_dev)
+		phy_start(sp->phy_dev);
 
 	return 0;
 }
@@ -949,7 +997,8 @@ static int ar231x_close(struct net_devic
 
 #endif
 
-	phy_stop(sp->phy_dev);
+	if (sp->phy_dev)
+		phy_stop(sp->phy_dev);
 
 	return 0;
 }
@@ -993,6 +1042,9 @@ static int ar231x_ioctl(struct net_devic
 {
 	struct ar231x_private *sp = netdev_priv(dev);
 
+	if (!sp->phy_dev)
+		return -ENODEV;
+
 	switch (cmd) {
 	case SIOCGMIIPHY:
 	case SIOCGMIIREG: