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>

drivers/net/ethernet/arc/Kconfig

@@ -17,10 +17,14 @@ config NET_VENDOR_ARC
 
 if NET_VENDOR_ARC
 
-config ARC_EMAC
-	tristate "ARC EMAC support"
+config ARC_EMAC_CORE
+	tristate
 	select MII
 	select PHYLIB
+
+config ARC_EMAC
+	tristate "ARC EMAC support"
+	select ARC_EMAC_CORE
 	depends on OF_IRQ
 	depends on OF_NET
 	---help---

drivers/net/ethernet/arc/Makefile

@@ -3,4 +3,5 @@
 #
 
 arc_emac-objs := emac_main.o emac_mdio.o
-obj-$(CONFIG_ARC_EMAC) += arc_emac.o
+obj-$(CONFIG_ARC_EMAC_CORE) += arc_emac.o
+obj-$(CONFIG_ARC_EMAC) += emac_arc.o

drivers/net/ethernet/arc/emac.h

@@ -124,6 +124,8 @@ struct buffer_state {
  */
 struct arc_emac_priv {
 	/* Devices */
+	const char *drv_name;
+	const char *drv_version;
 	struct device *dev;
 	struct phy_device *phy_dev;
 	struct mii_bus *bus;
@@ -206,5 +208,7 @@ static inline void arc_reg_clr(struct arc_emac_priv *priv, int reg, int mask)
 
 int arc_mdio_probe(struct arc_emac_priv *priv);
 int arc_mdio_remove(struct arc_emac_priv *priv);
+int arc_emac_probe(struct net_device *ndev, int interface);
+int arc_emac_remove(struct net_device *ndev);
 
 #endif /* ARC_EMAC_H */

drivers/net/ethernet/arc/emac_arc.c

@@ -0,0 +1,95 @@
+/**
+ * emac_arc.c - ARC EMAC specific glue layer
+ *
+ * Copyright (C) 2014 Romain Perier
+ *
+ * Romain Perier  <romain.perier@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/module.h>
+#include <linux/of_net.h>
+#include <linux/platform_device.h>
+
+#include "emac.h"
+
+#define DRV_NAME    "emac_arc"
+#define DRV_VERSION "1.0"
+
+static int emac_arc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct net_device *ndev;
+	struct arc_emac_priv *priv;
+	int interface, err;
+
+	if (!dev->of_node)
+		return -ENODEV;
+
+	ndev = alloc_etherdev(sizeof(struct arc_emac_priv));
+	if (!ndev)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, ndev);
+	SET_NETDEV_DEV(ndev, dev);
+
+	priv = netdev_priv(ndev);
+	priv->drv_name = DRV_NAME;
+	priv->drv_version = DRV_VERSION;
+
+	interface = of_get_phy_mode(dev->of_node);
+	if (interface < 0)
+		interface = PHY_INTERFACE_MODE_MII;
+
+	priv->clk = devm_clk_get(dev, "hclk");
+	if (IS_ERR(priv->clk)) {
+		dev_err(dev, "failed to retrieve host clock from device tree\n");
+		err = -EINVAL;
+		goto out_netdev;
+	}
+
+	err = arc_emac_probe(ndev, interface);
+out_netdev:
+	if (err)
+		free_netdev(ndev);
+	return err;
+}
+
+static int emac_arc_remove(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	int err;
+
+	err = arc_emac_remove(ndev);
+	free_netdev(ndev);
+	return err;
+}
+
+static const struct of_device_id emac_arc_dt_ids[] = {
+	{ .compatible = "snps,arc-emac" },
+	{ /* Sentinel */ }
+};
+
+static struct platform_driver emac_arc_driver = {
+	.probe = emac_arc_probe,
+	.remove = emac_arc_remove,
+	.driver = {
+		.name = DRV_NAME,
+		.of_match_table  = emac_arc_dt_ids,
+	},
+};
+
+module_platform_driver(emac_arc_driver);
+
+MODULE_AUTHOR("Romain Perier <romain.perier@gmail.com>");
+MODULE_DESCRIPTION("ARC EMAC platform driver");
+MODULE_LICENSE("GPL");

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 int arc_emac_set_settings(struct net_device *ndev,
 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 @@ static const struct net_device_ops arc_emac_netdev_ops = {
 #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 @@ static int arc_emac_probe(struct platform_device *pdev)
 		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 @@ static int arc_emac_probe(struct platform_device *pdev)
 
 	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 @@ static int arc_emac_probe(struct platform_device *pdev)
 	}
 
 	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_netif_api:
 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 @@ static int arc_emac_remove(struct platform_device *pdev)
 
 	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");