ethernet: arc: Add support for specific SoC layer device tree bindings

Some platforms have special bank registers which might be used to
select the correct clock or the right mode for Media Indepent Interface
controllers. Sometimes, it is also required to activate vcc regulators
in the right order to supply the ethernet controller at the right time.
This patch is an architecture refactoring of the arc-emac device driver.
It adds a new software design which allows to add specific platform
glue layer. Each platform has now its own module which performs custom
initialization and remove for the target and then calls to the
core driver.

Signed-off-by: Romain Perier <romain.perier@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/arc/emac_main.c b/drivers/net/ethernet/arc/emac_main.c
index bbc3157..b35c69e 100644
--- a/drivers/net/ethernet/arc/emac_main.c
+++ b/drivers/net/ethernet/arc/emac_main.c
@@ -26,8 +26,6 @@
 
 #include "emac.h"
 
-#define DRV_NAME	"arc_emac"
-#define DRV_VERSION	"1.0"
 
 /**
  * arc_emac_adjust_link - Adjust the PHY link duplex.
@@ -120,8 +118,10 @@
 static void arc_emac_get_drvinfo(struct net_device *ndev,
 				 struct ethtool_drvinfo *info)
 {
-	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
-	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+
+	strlcpy(info->driver, priv->drv_name, sizeof(info->driver));
+	strlcpy(info->version, priv->drv_version, sizeof(info->version));
 }
 
 static const struct ethtool_ops arc_emac_ethtool_ops = {
@@ -671,19 +671,16 @@
 #endif
 };
 
-static int arc_emac_probe(struct platform_device *pdev)
+int arc_emac_probe(struct net_device *ndev, int interface)
 {
-	struct device *dev = &pdev->dev;
+	struct device *dev = ndev->dev.parent;
 	struct resource res_regs;
 	struct device_node *phy_node;
 	struct arc_emac_priv *priv;
-	struct net_device *ndev;
 	const char *mac_addr;
 	unsigned int id, clock_frequency, irq;
 	int err;
 
-	if (!dev->of_node)
-		return -ENODEV;
 
 	/* Get PHY from device tree */
 	phy_node = of_parse_phandle(dev->of_node, "phy", 0);
@@ -706,12 +703,6 @@
 		return -ENODEV;
 	}
 
-	ndev = alloc_etherdev(sizeof(struct arc_emac_priv));
-	if (!ndev)
-		return -ENOMEM;
-
-	dev_set_drvdata(dev, ndev);
-	SET_NETDEV_DEV(ndev, dev);
 
 	ndev->netdev_ops = &arc_emac_netdev_ops;
 	ndev->ethtool_ops = &arc_emac_ethtool_ops;
@@ -724,28 +715,25 @@
 
 	priv->regs = devm_ioremap_resource(dev, &res_regs);
 	if (IS_ERR(priv->regs)) {
-		err = PTR_ERR(priv->regs);
-		goto out_netdev;
+		return PTR_ERR(priv->regs);
 	}
 	dev_dbg(dev, "Registers base address is 0x%p\n", priv->regs);
 
-	priv->clk = of_clk_get(dev->of_node, 0);
-	if (IS_ERR(priv->clk)) {
-		/* Get CPU clock frequency from device tree */
-		if (of_property_read_u32(dev->of_node, "clock-frequency",
-					&clock_frequency)) {
-			dev_err(dev, "failed to retrieve <clock-frequency> from device tree\n");
-			err = -EINVAL;
-			goto out_netdev;
-		}
-	} else {
+	if (priv->clk) {
 		err = clk_prepare_enable(priv->clk);
 		if (err) {
 			dev_err(dev, "failed to enable clock\n");
-			goto out_clkget;
+			return err;
 		}
 
 		clock_frequency = clk_get_rate(priv->clk);
+	} else {
+		/* Get CPU clock frequency from device tree */
+		if (of_property_read_u32(dev->of_node, "clock-frequency",
+					 &clock_frequency)) {
+			dev_err(dev, "failed to retrieve <clock-frequency> from device tree\n");
+			return -EINVAL;
+		}
 	}
 
 	id = arc_reg_get(priv, R_ID);
@@ -806,7 +794,7 @@
 	}
 
 	priv->phy_dev = of_phy_connect(ndev, phy_node, arc_emac_adjust_link, 0,
-				       PHY_INTERFACE_MODE_MII);
+				       interface);
 	if (!priv->phy_dev) {
 		dev_err(dev, "of_phy_connect() failed\n");
 		err = -ENODEV;
@@ -833,20 +821,15 @@
 out_mdio:
 	arc_mdio_remove(priv);
 out_clken:
-	if (!IS_ERR(priv->clk))
+	if (priv->clk)
 		clk_disable_unprepare(priv->clk);
-out_clkget:
-	if (!IS_ERR(priv->clk))
-		clk_put(priv->clk);
-out_netdev:
-	free_netdev(ndev);
 	return err;
 }
+EXPORT_SYMBOL_GPL(arc_emac_probe);
 
-static int arc_emac_remove(struct platform_device *pdev)
+int arc_emac_remove(struct net_device *ndev)
 {
-	struct device *dev = &pdev->dev;
-	struct net_device *ndev = dev_get_drvdata(dev);
+	struct device *dev = ndev->dev.parent;
 	struct arc_emac_priv *priv = netdev_priv(ndev);
 
 	phy_disconnect(priv->phy_dev);
@@ -857,31 +840,12 @@
 
 	if (!IS_ERR(priv->clk)) {
 		clk_disable_unprepare(priv->clk);
-		clk_put(priv->clk);
 	}
 
-	free_netdev(ndev);
 
 	return 0;
 }
-
-static const struct of_device_id arc_emac_dt_ids[] = {
-	{ .compatible = "snps,arc-emac" },
-	{ /* Sentinel */ }
-};
-MODULE_DEVICE_TABLE(of, arc_emac_dt_ids);
-
-static struct platform_driver arc_emac_driver = {
-	.probe = arc_emac_probe,
-	.remove = arc_emac_remove,
-	.driver = {
-		.name = DRV_NAME,
-		.owner = THIS_MODULE,
-		.of_match_table  = arc_emac_dt_ids,
-		},
-};
-
-module_platform_driver(arc_emac_driver);
+EXPORT_SYMBOL_GPL(arc_emac_remove);
 
 MODULE_AUTHOR("Alexey Brodkin <abrodkin@synopsys.com>");
 MODULE_DESCRIPTION("ARC EMAC driver");