[PATCH 1/6] net: Add EMAC ethernet driver found on Allwinner A10 SoC's

[PATCH 1/6] net: Add EMAC ethernet driver found on Allwinner A10 SoC's

[Maxime Ripard]

From: Stefan Roese <sr-ynQEQJNshbs@public.gmane.org>

The Allwinner A10 has an ethernet controller that seem to be developped
internally by them.

The exact feature set of this controller is unknown, since there is no
public documentation for this IP, and this driver is mostly the one
published by Allwinner that has been heavily cleaned up.

Signed-off-by: Stefan Roese <sr-ynQEQJNshbs@public.gmane.org>
Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 .../bindings/net/allwinner,sun4i-emac.txt          |  22 +
 drivers/net/ethernet/Kconfig                       |   1 +
 drivers/net/ethernet/Makefile                      |   1 +
 drivers/net/ethernet/allwinner/Kconfig             |  36 +
 drivers/net/ethernet/allwinner/Makefile            |   5 +
 drivers/net/ethernet/allwinner/sun4i-emac.c        | 960 +++++++++++++++++++++
 drivers/net/ethernet/allwinner/sun4i-emac.h        | 108 +++
 7 files changed, 1133 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/allwinner,sun4i-emac.txt
 create mode 100644 drivers/net/ethernet/allwinner/Kconfig
 create mode 100644 drivers/net/ethernet/allwinner/Makefile
 create mode 100644 drivers/net/ethernet/allwinner/sun4i-emac.c
 create mode 100644 drivers/net/ethernet/allwinner/sun4i-emac.h

diff --git a/Documentation/devicetree/bindings/net/allwinner,sun4i-emac.txt b/Documentation/devicetree/bindings/net/allwinner,sun4i-emac.txt
new file mode 100644
index 0000000..b90bfcd
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/allwinner,sun4i-emac.txt
@@ -0,0 +1,22 @@
+* Allwinner EMAC ethernet controller
+
+Required properties:
+- compatible: should be "allwinner,sun4i-emac".
+- reg: address and length of the register set for the device.
+- interrupts: interrupt for the device
+- phy: A phandle to a phy node defining the PHY address (as the reg
+  property, a single integer).
+- clocks: A phandle to the reference clock for this device
+
+Optional properties:
+- (local-)mac-address: mac address to be used by this driver
+
+Example:
+
+emac: ethernet@01c0b000 {
+       compatible = "allwinner,sun4i-emac";
+       reg = <0x01c0b000 0x1000>;
+       interrupts = <55>;
+       clocks = <&ahb_gates 17>;
+       phy = <&phy0>;
+};
diff --git a/drivers/net/ethernet/Kconfig b/drivers/net/ethernet/Kconfig
index ed956e0..18fd6fb 100644
--- a/drivers/net/ethernet/Kconfig
+++ b/drivers/net/ethernet/Kconfig
@@ -20,6 +20,7 @@ config SUNGEM_PHY
 source "drivers/net/ethernet/3com/Kconfig"
 source "drivers/net/ethernet/adaptec/Kconfig"
 source "drivers/net/ethernet/aeroflex/Kconfig"
+source "drivers/net/ethernet/allwinner/Kconfig"
 source "drivers/net/ethernet/alteon/Kconfig"
 source "drivers/net/ethernet/amd/Kconfig"
 source "drivers/net/ethernet/apple/Kconfig"
diff --git a/drivers/net/ethernet/Makefile b/drivers/net/ethernet/Makefile
index 8268d85..009da27 100644
--- a/drivers/net/ethernet/Makefile
+++ b/drivers/net/ethernet/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_NET_VENDOR_3COM) += 3com/
 obj-$(CONFIG_NET_VENDOR_8390) += 8390/
 obj-$(CONFIG_NET_VENDOR_ADAPTEC) += adaptec/
 obj-$(CONFIG_GRETH) += aeroflex/
+obj-$(CONFIG_NET_VENDOR_ALLWINNER) += allwinner/
 obj-$(CONFIG_NET_VENDOR_ALTEON) += alteon/
 obj-$(CONFIG_NET_VENDOR_AMD) += amd/
 obj-$(CONFIG_NET_VENDOR_APPLE) += apple/
diff --git a/drivers/net/ethernet/allwinner/Kconfig b/drivers/net/ethernet/allwinner/Kconfig
new file mode 100644
index 0000000..5d20fb0
--- /dev/null
+++ b/drivers/net/ethernet/allwinner/Kconfig
@@ -0,0 +1,36 @@
+#
+# Allwinner device configuration
+#
+
+config NET_VENDOR_ALLWINNER
+       bool "Allwinner devices"
+       default y
+       depends on ARCH_SUNXI
+       ---help---
+         If you have a network (Ethernet) card belonging to this
+	 class, say Y and read the Ethernet-HOWTO, available from
+	 <http://www.tldp.org/docs.html#howto>.
+
+	 Note that the answer to this question doesn't directly
+	 affect the kernel: saying N will just cause the configurator
+	 to skip all the questions about Davicom cards. If you say Y,
+	 you will be asked for your specific card in the following
+	 questions.
+
+if NET_VENDOR_ALLWINNER
+
+config SUN4I_EMAC
+        tristate "Allwinner A10 EMAC support"
+	depends on ARCH_SUNXI
+	depends on OF
+	select CRC32
+	select NET_CORE
+	select MII
+	select REGULATOR_FIXED_VOLTAGE
+        ---help---
+          Support for Allwinner A10 EMAC ethernet driver.
+
+          To compile this driver as a module, choose M here.  The module
+          will be called sun4i-emac.
+
+endif # NET_VENDOR_ALLWINNER
diff --git a/drivers/net/ethernet/allwinner/Makefile b/drivers/net/ethernet/allwinner/Makefile
new file mode 100644
index 0000000..03129f7
--- /dev/null
+++ b/drivers/net/ethernet/allwinner/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for the Allwinner device drivers.
+#
+
+obj-$(CONFIG_SUN4I_EMAC) += sun4i-emac.o
diff --git a/drivers/net/ethernet/allwinner/sun4i-emac.c b/drivers/net/ethernet/allwinner/sun4i-emac.c
new file mode 100644
index 0000000..b411344
--- /dev/null
+++ b/drivers/net/ethernet/allwinner/sun4i-emac.c
@@ -0,0 +1,960 @@
+/*
+ * Allwinner EMAC Fast Ethernet driver for Linux.
+ *
+ * Copyright 2012-2013 Stefan Roese <sr-ynQEQJNshbs@public.gmane.org>
+ * Copyright 2013 Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
+ *
+ * Based on the Linux driver provided by Allwinner:
+ * Copyright (C) 1997  Sten Wang
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/clk.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/mii.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_mdio.h>
+#include <linux/of_net.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/phy.h>
+
+#include "sun4i-emac.h"
+
+#define DRV_NAME		"sun4i-emac"
+#define DRV_VERSION		"1.02"
+
+#define EMAC_MAX_FRAME_LEN	0x0600
+
+/* Transmit timeout, default 5 seconds. */
+static int watchdog = 5000;
+module_param(watchdog, int, 0400);
+MODULE_PARM_DESC(watchdog, "transmit timeout in milliseconds");
+
+/* EMAC register address locking.
+ *
+ * The EMAC uses an address register to control where data written
+ * to the data register goes. This means that the address register
+ * must be preserved over interrupts or similar calls.
+ *
+ * During interrupt and other critical calls, a spinlock is used to
+ * protect the system, but the calls themselves save the address
+ * in the address register in case they are interrupting another
+ * access to the device.
+ *
+ * For general accesses a lock is provided so that calls which are
+ * allowed to sleep are serialised so that the address register does
+ * not need to be saved. This lock also serves to serialise access
+ * to the EEPROM and PHY access registers which are shared between
+ * these two devices.
+ */
+
+/* The driver supports the original EMACE, and now the two newer
+ * devices, EMACA and EMACB.
+ */
+
+struct emac_board_info {
+	struct clk		*clk;
+	struct device		*dev;
+	struct platform_device	*pdev;
+	spinlock_t		lock;
+	void __iomem		*membase;
+	u32			msg_enable;
+	struct net_device	*ndev;
+	struct sk_buff		*skb_last;
+	u16			tx_fifo_stat;
+
+	int			emacrx_completed_flag;
+
+	struct phy_device	*phy_dev;
+	struct device_node	*phy_node;
+	unsigned int		link;
+	unsigned int		speed;
+	unsigned int		duplex;
+
+	phy_interface_t		phy_interface;
+};
+
+static void emac_update_speed(struct net_device *dev)
+{
+	struct emac_board_info *db = netdev_priv(dev);
+	unsigned int reg_val;
+
+	/* set EMAC SPEED, depend on PHY  */
+	reg_val = readl(db->membase + EMAC_MAC_SUPP_REG);
+	reg_val &= ~(0x1 << 8);
+	if (db->speed == SPEED_100)
+		reg_val |= 1 << 8;
+	writel(reg_val, db->membase + EMAC_MAC_SUPP_REG);
+}
+
+static void emac_update_duplex(struct net_device *dev)
+{
+	struct emac_board_info *db = netdev_priv(dev);
+	unsigned int reg_val;
+
+	/* set duplex depend on phy */
+	reg_val = readl(db->membase + EMAC_MAC_CTL1_REG);
+	reg_val &= ~EMAC_MAC_CTL1_DUPLEX_EN;
+	if (db->duplex)
+		reg_val |= EMAC_MAC_CTL1_DUPLEX_EN;
+	writel(reg_val, db->membase + EMAC_MAC_CTL1_REG);
+}
+
+static void emac_handle_link_change(struct net_device *dev)
+{
+	struct emac_board_info *db = netdev_priv(dev);
+	struct phy_device *phydev = db->phy_dev;
+	unsigned long flags;
+	int status_change = 0;
+
+	if (phydev->link) {
+		if (db->speed != phydev->speed) {
+			spin_lock_irqsave(&db->lock, flags);
+			db->speed = phydev->speed;
+			emac_update_speed(dev);
+			spin_unlock_irqrestore(&db->lock, flags);
+			status_change = 1;
+		}
+
+		if (db->duplex != phydev->duplex) {
+			spin_lock_irqsave(&db->lock, flags);
+			db->duplex = phydev->duplex;
+			emac_update_duplex(dev);
+			spin_unlock_irqrestore(&db->lock, flags);
+			status_change = 1;
+		}
+	}
+
+	if (phydev->link != db->link) {
+		if (!phydev->link) {
+			db->speed = 0;
+			db->duplex = -1;
+		}
+		db->link = phydev->link;
+
+		status_change = 1;
+	}
+
+	if (status_change)
+		phy_print_status(phydev);
+}
+
+static int emac_mdio_probe(struct net_device *dev)
+{
+	struct emac_board_info *db = netdev_priv(dev);
+
+	/* to-do: PHY interrupts are currently not supported */
+
+	/* attach the mac to the phy */
+	db->phy_dev = of_phy_connect(db->ndev, db->phy_node,
+				     &emac_handle_link_change, 0,
+				     db->phy_interface);
+	if (!db->phy_dev) {
+		netdev_err(db->ndev, "could not find the PHY\n");
+		return -ENODEV;
+	}
+
+	/* mask with MAC supported features */
+	db->phy_dev->supported &= PHY_BASIC_FEATURES;
+	db->phy_dev->advertising = db->phy_dev->supported;
+
+	db->link = 0;
+	db->speed = 0;
+	db->duplex = -1;
+
+	return 0;
+}
+
+static void emac_mdio_remove(struct net_device *dev)
+{
+	struct emac_board_info *db = netdev_priv(dev);
+
+	phy_disconnect(db->phy_dev);
+	db->phy_dev = NULL;
+}
+
+static void emac_reset(struct emac_board_info *db)
+{
+	dev_dbg(db->dev, "resetting device\n");
+
+	/* RESET device */
+	writel(0, db->membase + EMAC_CTL_REG);
+	udelay(200);
+	writel(EMAC_CTL_RESET, db->membase + EMAC_CTL_REG);
+	udelay(200);
+}
+
+static void emac_outblk_32bit(void __iomem *reg, void *data, int count)
+{
+	writesl(reg, data, round_up(count, 4) / 4);
+}
+
+static void emac_inblk_32bit(void __iomem *reg, void *data, int count)
+{
+	readsl(reg, data, round_up(count, 4) / 4);
+}
+
+static int emac_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
+{
+	struct emac_board_info *dm = netdev_priv(dev);
+	struct phy_device *phydev = dm->phy_dev;
+
+	if (!netif_running(dev))
+		return -EINVAL;
+
+	if (!phydev)
+		return -ENODEV;
+
+	return phy_mii_ioctl(phydev, rq, cmd);
+}
+
+/* ethtool ops */
+static void emac_get_drvinfo(struct net_device *dev,
+			      struct ethtool_drvinfo *info)
+{
+	strlcpy(info->driver, DRV_NAME, sizeof(DRV_NAME));
+	strlcpy(info->version, DRV_VERSION, sizeof(DRV_VERSION));
+	strlcpy(info->bus_info, dev_name(&dev->dev), sizeof(info->bus_info));
+}
+
+static int emac_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
+{
+	struct emac_board_info *dm = netdev_priv(dev);
+	struct phy_device *phydev = dm->phy_dev;
+
+	if (!phydev)
+		return -ENODEV;
+
+	return phy_ethtool_gset(phydev, cmd);
+}
+
+static int emac_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
+{
+	struct emac_board_info *dm = netdev_priv(dev);
+	struct phy_device *phydev = dm->phy_dev;
+
+	if (!phydev)
+		return -ENODEV;
+
+	return phy_ethtool_sset(phydev, cmd);
+}
+
+static const struct ethtool_ops emac_ethtool_ops = {
+	.get_drvinfo	= emac_get_drvinfo,
+	.get_settings	= emac_get_settings,
+	.set_settings	= emac_set_settings,
+	.get_link	= ethtool_op_get_link,
+};
+
+unsigned int emac_setup(struct net_device *ndev)
+{
+	struct emac_board_info *db = netdev_priv(ndev);
+	unsigned int reg_val;
+
+	/* set up TX */
+	reg_val = readl(db->membase + EMAC_TX_MODE_REG);
+
+	writel(reg_val | EMAC_TX_MODE_ABORTED_FRAME_EN,
+		db->membase + EMAC_TX_MODE_REG);
+
+	/* set up RX */
+	reg_val = readl(db->membase + EMAC_RX_CTL_REG);
+
+	writel(reg_val | EMAC_RX_CTL_PASS_LEN_OOR_EN |
+		EMAC_RX_CTL_ACCEPT_UNICAST_EN | EMAC_RX_CTL_DA_FILTER_EN |
+		EMAC_RX_CTL_ACCEPT_MULTICAST_EN |
+		EMAC_RX_CTL_ACCEPT_BROADCAST_EN,
+		db->membase + EMAC_RX_CTL_REG);
+
+	/* set MAC */
+	/* set MAC CTL0 */
+	reg_val = readl(db->membase + EMAC_MAC_CTL0_REG);
+	writel(reg_val | EMAC_MAC_CTL0_RX_FLOW_CTL_EN |
+		EMAC_MAC_CTL0_TX_FLOW_CTL_EN,
+		db->membase + EMAC_MAC_CTL0_REG);
+
+	/* set MAC CTL1 */
+	reg_val = readl(db->membase + EMAC_MAC_CTL1_REG);
+	reg_val |= EMAC_MAC_CTL1_LEN_CHECK_EN;
+	reg_val |= EMAC_MAC_CTL1_CRC_EN;
+	reg_val |= EMAC_MAC_CTL1_PAD_EN;
+	writel(reg_val, db->membase + EMAC_MAC_CTL1_REG);
+
+	/* set up IPGT */
+	writel(EMAC_MAC_IPGT_FULL_DUPLEX, db->membase + EMAC_MAC_IPGT_REG);
+
+	/* set up IPGR */
+	writel((EMAC_MAC_IPGR_IPG1 << 8) | EMAC_MAC_IPGR_IPG2,
+		db->membase + EMAC_MAC_IPGR_REG);
+
+	/* set up Collison window */
+	writel((EMAC_MAC_CLRT_COLLISION_WINDOW << 8) | EMAC_MAC_CLRT_RM,
+		db->membase + EMAC_MAC_CLRT_REG);
+
+	/* set up Max Frame Length */
+	writel(EMAC_MAX_FRAME_LEN,
+		db->membase + EMAC_MAC_MAXF_REG);
+
+	return 0;
+}
+
+unsigned int emac_powerup(struct net_device *ndev)
+{
+	struct emac_board_info *db = netdev_priv(ndev);
+	unsigned int reg_val;
+
+	/* initial EMAC */
+	/* flush RX FIFO */
+	reg_val = readl(db->membase + EMAC_RX_CTL_REG);
+	reg_val |= 0x8;
+	writel(reg_val, db->membase + EMAC_RX_CTL_REG);
+	udelay(1);
+
+	/* initial MAC */
+	/* soft reset MAC */
+	reg_val = readl(db->membase + EMAC_MAC_CTL0_REG);
+	reg_val &= ~EMAC_MAC_CTL0_SOFT_RESET;
+	writel(reg_val, db->membase + EMAC_MAC_CTL0_REG);
+
+	/* set MII clock */
+	reg_val = readl(db->membase + EMAC_MAC_MCFG_REG);
+	reg_val &= (~(0xf << 2));
+	reg_val |= (0xD << 2);
+	writel(reg_val, db->membase + EMAC_MAC_MCFG_REG);
+
+	/* clear RX counter */
+	writel(0x0, db->membase + EMAC_RX_FBC_REG);
+
+	/* disable all interrupt and clear interrupt status */
+	writel(0, db->membase + EMAC_INT_CTL_REG);
+	reg_val = readl(db->membase + EMAC_INT_STA_REG);
+	writel(reg_val, db->membase + EMAC_INT_STA_REG);
+
+	udelay(1);
+
+	/* set up EMAC */
+	emac_setup(ndev);
+
+	/* set mac_address to chip */
+	writel(ndev->dev_addr[0] << 16 | ndev->dev_addr[1] << 8 | ndev->
+	       dev_addr[2], db->membase + EMAC_MAC_A1_REG);
+	writel(ndev->dev_addr[3] << 16 | ndev->dev_addr[4] << 8 | ndev->
+	       dev_addr[5], db->membase + EMAC_MAC_A0_REG);
+
+	mdelay(1);
+
+	return 0;
+}
+
+static int emac_set_mac_address(struct net_device *dev, void *p)
+{
+	struct sockaddr *addr = p;
+	struct emac_board_info *db = netdev_priv(dev);
+
+	if (netif_running(dev))
+		return -EBUSY;
+
+	memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
+
+	writel(dev->dev_addr[0] << 16 | dev->dev_addr[1] << 8 | dev->
+	       dev_addr[2], db->membase + EMAC_MAC_A1_REG);
+	writel(dev->dev_addr[3] << 16 | dev->dev_addr[4] << 8 | dev->
+	       dev_addr[5], db->membase + EMAC_MAC_A0_REG);
+
+	return 0;
+}
+
+/* Initialize emac board */
+static void emac_init_device(struct net_device *dev)
+{
+	struct emac_board_info *db = netdev_priv(dev);
+	unsigned long flags;
+	unsigned int reg_val;
+
+	spin_lock_irqsave(&db->lock, flags);
+
+	emac_update_speed(dev);
+	emac_update_duplex(dev);
+
+	/* enable RX/TX */
+	reg_val = readl(db->membase + EMAC_CTL_REG);
+	writel(reg_val | EMAC_CTL_RESET | EMAC_CTL_TX_EN | EMAC_CTL_RX_EN,
+		db->membase + EMAC_CTL_REG);
+
+	/* enable RX/TX0/RX Hlevel interrup */
+	reg_val = readl(db->membase + EMAC_INT_CTL_REG);
+	reg_val |= (0xf << 0) | (0x01 << 8);
+	writel(reg_val, db->membase + EMAC_INT_CTL_REG);
+
+	spin_unlock_irqrestore(&db->lock, flags);
+}
+
+/* Our watchdog timed out. Called by the networking layer */
+static void emac_timeout(struct net_device *dev)
+{
+	struct emac_board_info *db = netdev_priv(dev);
+	unsigned long flags;
+
+	if (netif_msg_timer(db))
+		dev_err(db->dev, "tx time out.\n");
+
+	/* Save previous register address */
+	spin_lock_irqsave(&db->lock, flags);
+
+	netif_stop_queue(dev);
+	emac_reset(db);
+	emac_init_device(dev);
+	/* We can accept TX packets again */
+	dev->trans_start = jiffies;
+	netif_wake_queue(dev);
+
+	/* Restore previous register address */
+	spin_unlock_irqrestore(&db->lock, flags);
+}
+
+/* Hardware start transmission.
+ * Send a packet to media from the upper layer.
+ */
+static int emac_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct emac_board_info *db = netdev_priv(dev);
+	unsigned long channel;
+	unsigned long flags;
+
+	channel = db->tx_fifo_stat & 3;
+	if (channel == 3)
+		return 1;
+
+	channel = (channel == 1 ? 1 : 0);
+
+	spin_lock_irqsave(&db->lock, flags);
+
+	writel(channel, db->membase + EMAC_TX_INS_REG);
+
+	emac_outblk_32bit(db->membase + EMAC_TX_IO_DATA_REG,
+			skb->data, skb->len);
+	dev->stats.tx_bytes += skb->len;
+
+	db->tx_fifo_stat |= 1 << channel;
+	/* TX control: First packet immediately send, second packet queue */
+	if (channel == 0) {
+		/* set TX len */
+		writel(skb->len, db->membase + EMAC_TX_PL0_REG);
+		/* start translate from fifo to phy */
+		writel(readl(db->membase + EMAC_TX_CTL0_REG) | 1,
+		       db->membase + EMAC_TX_CTL0_REG);
+
+		/* save the time stamp */
+		dev->trans_start = jiffies;
+	} else if (channel == 1) {
+		/* set TX len */
+		writel(skb->len, db->membase + EMAC_TX_PL1_REG);
+		/* start translate from fifo to phy */
+		writel(readl(db->membase + EMAC_TX_CTL1_REG) | 1,
+		       db->membase + EMAC_TX_CTL1_REG);
+
+		/* save the time stamp */
+		dev->trans_start = jiffies;
+	}
+
+	if ((db->tx_fifo_stat & 3) == 3) {
+		/* Second packet */
+		netif_stop_queue(dev);
+	}
+
+	spin_unlock_irqrestore(&db->lock, flags);
+
+	/* free this SKB */
+	dev_kfree_skb(skb);
+
+	return NETDEV_TX_OK;
+}
+
+/* EMAC interrupt handler
+ * receive the packet to upper layer, free the transmitted packet
+ */
+static void emac_tx_done(struct net_device *dev, struct emac_board_info *db,
+			  unsigned int tx_status)
+{
+	/* One packet sent complete */
+	db->tx_fifo_stat &= ~(tx_status & 3);
+	if (3 == (tx_status & 3))
+		dev->stats.tx_packets += 2;
+	else
+		dev->stats.tx_packets++;
+
+	if (netif_msg_tx_done(db))
+		dev_dbg(db->dev, "tx done, NSR %02x\n", tx_status);
+
+	netif_wake_queue(dev);
+}
+
+/* Received a packet and pass to upper layer
+ */
+static void emac_rx(struct net_device *dev)
+{
+	struct emac_board_info *db = netdev_priv(dev);
+	struct sk_buff *skb;
+	u8 *rdptr;
+	bool good_packet;
+	static int rxlen_last;
+	unsigned int reg_val;
+	u32 rxhdr, rxstatus, rxcount, rxlen;
+
+	/* Check packet ready or not */
+	while (1) {
+		/* race warning: the first packet might arrive with
+		 * the interrupts disabled, but the second will fix
+		 * it
+		 */
+		rxcount = readl(db->membase + EMAC_RX_FBC_REG);
+
+		if (netif_msg_rx_status(db))
+			dev_dbg(db->dev, "RXCount: %x\n", rxcount);
+
+		if ((db->skb_last != NULL) && (rxlen_last > 0)) {
+			dev->stats.rx_bytes += rxlen_last;
+
+			/* Pass to upper layer */
+			db->skb_last->protocol = eth_type_trans(db->skb_last,
+								dev);
+			netif_rx(db->skb_last);
+			dev->stats.rx_packets++;
+			db->skb_last = NULL;
+			rxlen_last = 0;
+
+			reg_val = readl(db->membase + EMAC_RX_CTL_REG);
+			reg_val &= ~EMAC_RX_CTL_DMA_EN;
+			writel(reg_val, db->membase + EMAC_RX_CTL_REG);
+		}
+
+		if (!rxcount) {
+			db->emacrx_completed_flag = 1;
+			reg_val = readl(db->membase + EMAC_INT_CTL_REG);
+			reg_val |= (0xf << 0) | (0x01 << 8);
+			writel(reg_val, db->membase + EMAC_INT_CTL_REG);
+
+			/* had one stuck? */
+			rxcount = readl(db->membase + EMAC_RX_FBC_REG);
+			if (!rxcount)
+				return;
+		}
+
+		reg_val = readl(db->membase + EMAC_RX_IO_DATA_REG);
+		if (netif_msg_rx_status(db))
+			dev_dbg(db->dev, "receive header: %x\n", reg_val);
+		if (reg_val != EMAC_UNDOCUMENTED_MAGIC) {
+			/* disable RX */
+			reg_val = readl(db->membase + EMAC_CTL_REG);
+			writel(reg_val & ~EMAC_CTL_RX_EN,
+			       db->membase + EMAC_CTL_REG);
+
+			/* Flush RX FIFO */
+			reg_val = readl(db->membase + EMAC_RX_CTL_REG);
+			writel(reg_val | (1 << 3),
+			       db->membase + EMAC_RX_CTL_REG);
+
+			do {
+				reg_val = readl(db->membase + EMAC_RX_CTL_REG);
+			} while (reg_val & (1 << 3));
+
+			/* enable RX */
+			reg_val = readl(db->membase + EMAC_CTL_REG);
+			writel(reg_val | EMAC_CTL_RX_EN,
+			       db->membase + EMAC_CTL_REG);
+			reg_val = readl(db->membase + EMAC_INT_CTL_REG);
+			reg_val |= (0xf << 0) | (0x01 << 8);
+			writel(reg_val, db->membase + EMAC_INT_CTL_REG);
+
+			db->emacrx_completed_flag = 1;
+
+			return;
+		}
+
+		/* A packet ready now  & Get status/length */
+		good_packet = true;
+
+		emac_inblk_32bit(db->membase + EMAC_RX_IO_DATA_REG,
+				&rxhdr, sizeof(rxhdr));
+
+		if (netif_msg_rx_status(db))
+			dev_dbg(db->dev, "rxhdr: %x\n", *((int *)(&rxhdr)));
+
+		rxlen = EMAC_RX_IO_DATA_LEN(rxhdr);
+		rxstatus = EMAC_RX_IO_DATA_STATUS(rxhdr);
+
+		if (netif_msg_rx_status(db))
+			dev_dbg(db->dev, "RX: status %02x, length %04x\n",
+				rxstatus, rxlen);
+
+		/* Packet Status check */
+		if (rxlen < 0x40) {
+			good_packet = false;
+			if (netif_msg_rx_err(db))
+				dev_dbg(db->dev, "RX: Bad Packet (runt)\n");
+		}
+
+		if (unlikely(!(rxstatus & EMAC_RX_IO_DATA_STATUS_OK))) {
+			good_packet = false;
+
+			if (rxstatus & EMAC_RX_IO_DATA_STATUS_CRC_ERR) {
+				if (netif_msg_rx_err(db))
+					dev_dbg(db->dev, "crc error\n");
+				dev->stats.rx_crc_errors++;
+			}
+
+			if (rxstatus & EMAC_RX_IO_DATA_STATUS_LEN_ERR) {
+				if (netif_msg_rx_err(db))
+					dev_dbg(db->dev, "length error\n");
+				dev->stats.rx_length_errors++;
+			}
+		}
+
+		/* Move data from EMAC */
+		skb = dev_alloc_skb(rxlen + 4);
+		if (good_packet && skb) {
+			skb_reserve(skb, 2);
+			rdptr = (u8 *) skb_put(skb, rxlen - 4);
+
+			/* Read received packet from RX SRAM */
+			if (netif_msg_rx_status(db))
+				dev_dbg(db->dev, "RxLen %x\n", rxlen);
+
+			emac_inblk_32bit(db->membase + EMAC_RX_IO_DATA_REG,
+					rdptr, rxlen);
+			dev->stats.rx_bytes += rxlen;
+
+			/* Pass to upper layer */
+			skb->protocol = eth_type_trans(skb, dev);
+			netif_rx(skb);
+			dev->stats.rx_packets++;
+		}
+	}
+}
+
+static irqreturn_t emac_interrupt(int irq, void *dev_id)
+{
+	struct net_device *dev = dev_id;
+	struct emac_board_info *db = netdev_priv(dev);
+	int int_status;
+	unsigned long flags;
+	unsigned int reg_val;
+
+	/* A real interrupt coming */
+
+	/* holders of db->lock must always block IRQs */
+	spin_lock_irqsave(&db->lock, flags);
+
+	/* Disable all interrupts */
+	writel(0, db->membase + EMAC_INT_CTL_REG);
+
+	/* Got EMAC interrupt status */
+	/* Got ISR */
+	int_status = readl(db->membase + EMAC_INT_STA_REG);
+	/* Clear ISR status */
+	writel(int_status, db->membase + EMAC_INT_STA_REG);
+
+	if (netif_msg_intr(db))
+		dev_dbg(db->dev, "emac interrupt %02x\n", int_status);
+
+	/* Received the coming packet */
+	if ((int_status & 0x100) && (db->emacrx_completed_flag == 1)) {
+		/* carrier lost */
+		db->emacrx_completed_flag = 0;
+		emac_rx(dev);
+	}
+
+	/* Transmit Interrupt check */
+	if (int_status & (0x01 | 0x02))
+		emac_tx_done(dev, db, int_status);
+
+	if (int_status & (0x04 | 0x08))
+		netdev_info(dev, " ab : %x\n", int_status);
+
+	/* Re-enable interrupt mask */
+	if (db->emacrx_completed_flag == 1) {
+		reg_val = readl(db->membase + EMAC_INT_CTL_REG);
+		reg_val |= (0xf << 0) | (0x01 << 8);
+		writel(reg_val, db->membase + EMAC_INT_CTL_REG);
+	}
+	spin_unlock_irqrestore(&db->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_NET_POLL_CONTROLLER
+/*
+ * Used by netconsole
+ */
+static void emac_poll_controller(struct net_device *dev)
+{
+	disable_irq(dev->irq);
+	emac_interrupt(dev->irq, dev);
+	enable_irq(dev->irq);
+}
+#endif
+
+/*  Open the interface.
+ *  The interface is opened whenever "ifconfig" actives it.
+ */
+static int emac_open(struct net_device *dev)
+{
+	struct emac_board_info *db = netdev_priv(dev);
+	int ret;
+
+	if (netif_msg_ifup(db))
+		dev_dbg(db->dev, "enabling %s\n", dev->name);
+
+	if (devm_request_irq(db->dev, dev->irq, &emac_interrupt,
+			     0, dev->name, dev))
+		return -EAGAIN;
+
+	/* Initialize EMAC board */
+	emac_reset(db);
+	emac_init_device(dev);
+
+	ret = emac_mdio_probe(dev);
+	if (ret < 0) {
+		netdev_err(dev, "cannot probe MDIO bus\n");
+		return ret;
+	}
+
+	phy_start(db->phy_dev);
+	netif_start_queue(dev);
+
+	return 0;
+}
+
+static void emac_shutdown(struct net_device *dev)
+{
+	unsigned int reg_val;
+	struct emac_board_info *db = netdev_priv(dev);
+
+	/* Disable all interrupt */
+	writel(0, db->membase + EMAC_INT_CTL_REG);
+
+	/* clear interupt status */
+	reg_val = readl(db->membase + EMAC_INT_STA_REG);
+	writel(reg_val, db->membase + EMAC_INT_STA_REG);
+
+	/* Disable RX/TX */
+	reg_val = readl(db->membase + EMAC_CTL_REG);
+	reg_val &= ~(EMAC_CTL_TX_EN | EMAC_CTL_RX_EN | EMAC_CTL_RESET);
+	writel(reg_val, db->membase + EMAC_CTL_REG);
+}
+
+/* Stop the interface.
+ * The interface is stopped when it is brought.
+ */
+static int emac_stop(struct net_device *ndev)
+{
+	struct emac_board_info *db = netdev_priv(ndev);
+
+	if (netif_msg_ifdown(db))
+		dev_dbg(db->dev, "shutting down %s\n", ndev->name);
+
+	netif_stop_queue(ndev);
+	netif_carrier_off(ndev);
+
+	phy_stop(db->phy_dev);
+
+	emac_mdio_remove(ndev);
+
+	emac_shutdown(ndev);
+
+	return 0;
+}
+
+static const struct net_device_ops emac_netdev_ops = {
+	.ndo_open		= emac_open,
+	.ndo_stop		= emac_stop,
+	.ndo_start_xmit		= emac_start_xmit,
+	.ndo_tx_timeout		= emac_timeout,
+	.ndo_do_ioctl		= emac_ioctl,
+	.ndo_change_mtu		= eth_change_mtu,
+	.ndo_validate_addr	= eth_validate_addr,
+	.ndo_set_mac_address	= emac_set_mac_address,
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	.ndo_poll_controller	= emac_poll_controller,
+#endif
+};
+
+/* Search EMAC board, allocate space and register it
+ */
+static int emac_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct emac_board_info *db;
+	struct net_device *ndev;
+	int ret = 0;
+	const char *mac_addr;
+
+	ndev = alloc_etherdev(sizeof(struct emac_board_info));
+	if (!ndev) {
+		dev_err(&pdev->dev, "could not allocate device.\n");
+		return -ENOMEM;
+	}
+
+	SET_NETDEV_DEV(ndev, &pdev->dev);
+
+	db = netdev_priv(ndev);
+	memset(db, 0, sizeof(*db));
+
+	db->dev = &pdev->dev;
+	db->ndev = ndev;
+	db->pdev = pdev;
+
+	spin_lock_init(&db->lock);
+
+	db->membase = of_iomap(np, 0);
+	if (!db->membase) {
+		dev_err(&pdev->dev, "failed to remap registers\n");
+		return -ENOMEM;
+		goto out;
+	}
+
+	/* fill in parameters for net-dev structure */
+	ndev->base_addr = (unsigned long)db->membase;
+	ndev->irq = irq_of_parse_and_map(np, 0);
+	if (ndev->irq == -ENXIO) {
+		netdev_err(ndev, "No irq resource\n");
+		ret = ndev->irq;
+		goto out;
+	}
+
+	db->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(db->clk))
+		goto out;
+
+	clk_prepare_enable(db->clk);
+
+	db->phy_node = of_parse_phandle(np, "phy", 0);
+	if (!db->phy_node) {
+		dev_err(&pdev->dev, "no associated PHY\n");
+		ret = -ENODEV;
+		goto out;
+	}
+
+	/* Read MAC-address from DT */
+	mac_addr = of_get_mac_address(np);
+	if (mac_addr)
+		memcpy(ndev->dev_addr, mac_addr, ETH_ALEN);
+
+	/* Check if the MAC address is valid, if not get a random one */
+	if (!is_valid_ether_addr(ndev->dev_addr)) {
+		eth_hw_addr_random(ndev);
+		dev_warn(&pdev->dev, "using random MAC address %pM\n",
+			 ndev->dev_addr);
+	}
+
+	db->emacrx_completed_flag = 1;
+	emac_powerup(ndev);
+	emac_reset(db);
+
+	ether_setup(ndev);
+
+	ndev->netdev_ops = &emac_netdev_ops;
+	ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
+	ndev->ethtool_ops = &emac_ethtool_ops;
+
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	ndev->poll_controller = &emac_poll_controller;
+#endif
+
+	platform_set_drvdata(pdev, ndev);
+
+	/* Carrier starts down, phylib will bring it up */
+	netif_carrier_off(ndev);
+
+	ret = register_netdev(ndev);
+	if (ret) {
+		dev_err(&pdev->dev, "Registering netdev failed!\n");
+		ret = -ENODEV;
+		goto out;
+	}
+
+	dev_info(&pdev->dev, "%s: at %p, IRQ %d MAC: %pM\n",
+		 ndev->name, db->membase, ndev->irq, ndev->dev_addr);
+
+	return 0;
+
+out:
+	dev_err(db->dev, "not found (%d).\n", ret);
+
+	free_netdev(ndev);
+
+	return ret;
+}
+
+static int emac_remove(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	unregister_netdev(ndev);
+	free_netdev(ndev);
+
+	dev_dbg(&pdev->dev, "released and freed device\n");
+	return 0;
+}
+
+static int emac_suspend(struct platform_device *dev, pm_message_t state)
+{
+	struct net_device *ndev = platform_get_drvdata(dev);
+
+	netif_carrier_off(ndev);
+	netif_device_detach(ndev);
+	emac_shutdown(ndev);
+
+	return 0;
+}
+
+static int emac_resume(struct platform_device *dev)
+{
+	struct net_device *ndev = platform_get_drvdata(dev);
+	struct emac_board_info *db = netdev_priv(ndev);
+
+	emac_reset(db);
+	emac_init_device(ndev);
+	netif_device_attach(ndev);
+
+	return 0;
+}
+
+static const struct of_device_id emac_of_match[] = {
+	{.compatible = "allwinner,sun4i-emac",},
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, emac_of_match);
+
+static struct platform_driver emac_driver = {
+	.driver = {
+		.name = "sun4i-emac",
+		.of_match_table = emac_of_match,
+	},
+	.probe = emac_probe,
+	.remove = emac_remove,
+	.suspend = emac_suspend,
+	.resume = emac_resume,
+};
+
+module_platform_driver(emac_driver);
+
+MODULE_AUTHOR("Stefan Roese <sr-ynQEQJNshbs@public.gmane.org>");
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>");
+MODULE_DESCRIPTION("Allwinner A10 emac network driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/net/ethernet/allwinner/sun4i-emac.h b/drivers/net/ethernet/allwinner/sun4i-emac.h
new file mode 100644
index 0000000..38c72d9
--- /dev/null
+++ b/drivers/net/ethernet/allwinner/sun4i-emac.h
@@ -0,0 +1,108 @@
+/*
+ * Allwinner EMAC Fast Ethernet driver for Linux.
+ *
+ * Copyright 2012 Stefan Roese <sr-ynQEQJNshbs@public.gmane.org>
+ * Copyright 2013 Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
+ *
+ * Based on the Linux driver provided by Allwinner:
+ * Copyright (C) 1997  Sten Wang
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef _SUN4I_EMAC_H_
+#define _SUN4I_EMAC_H_
+
+#define EMAC_CTL_REG		(0x00)
+#define EMAC_CTL_RESET			(1 << 0)
+#define EMAC_CTL_TX_EN			(1 << 1)
+#define EMAC_CTL_RX_EN			(1 << 2)
+#define EMAC_TX_MODE_REG	(0x04)
+#define EMAC_TX_MODE_ABORTED_FRAME_EN	(1 << 0)
+#define EMAC_TX_MODE_DMA_EN		(1 << 1)
+#define EMAC_TX_FLOW_REG	(0x08)
+#define EMAC_TX_CTL0_REG	(0x0c)
+#define EMAC_TX_CTL1_REG	(0x10)
+#define EMAC_TX_INS_REG		(0x14)
+#define EMAC_TX_PL0_REG		(0x18)
+#define EMAC_TX_PL1_REG		(0x1c)
+#define EMAC_TX_STA_REG		(0x20)
+#define EMAC_TX_IO_DATA_REG	(0x24)
+#define EMAC_TX_IO_DATA1_REG	(0x28)
+#define EMAC_TX_TSVL0_REG	(0x2c)
+#define EMAC_TX_TSVH0_REG	(0x30)
+#define EMAC_TX_TSVL1_REG	(0x34)
+#define EMAC_TX_TSVH1_REG	(0x38)
+#define EMAC_RX_CTL_REG		(0x3c)
+#define EMAC_RX_CTL_AUTO_DRQ_EN		(1 << 1)
+#define EMAC_RX_CTL_DMA_EN		(1 << 2)
+#define EMAC_RX_CTL_PASS_ALL_EN		(1 << 4)
+#define EMAC_RX_CTL_PASS_CTL_EN		(1 << 5)
+#define EMAC_RX_CTL_PASS_CRC_ERR_EN	(1 << 6)
+#define EMAC_RX_CTL_PASS_LEN_ERR_EN	(1 << 7)
+#define EMAC_RX_CTL_PASS_LEN_OOR_EN	(1 << 8)
+#define EMAC_RX_CTL_ACCEPT_UNICAST_EN	(1 << 16)
+#define EMAC_RX_CTL_DA_FILTER_EN	(1 << 17)
+#define EMAC_RX_CTL_ACCEPT_MULTICAST_EN	(1 << 20)
+#define EMAC_RX_CTL_HASH_FILTER_EN	(1 << 21)
+#define EMAC_RX_CTL_ACCEPT_BROADCAST_EN	(1 << 22)
+#define EMAC_RX_CTL_SA_FILTER_EN	(1 << 24)
+#define EMAC_RX_CTL_SA_FILTER_INVERT_EN	(1 << 25)
+#define EMAC_RX_HASH0_REG	(0x40)
+#define EMAC_RX_HASH1_REG	(0x44)
+#define EMAC_RX_STA_REG		(0x48)
+#define EMAC_RX_IO_DATA_REG	(0x4c)
+#define EMAC_RX_IO_DATA_LEN(x)		(x & 0xffff)
+#define EMAC_RX_IO_DATA_STATUS(x)	((x >> 16) & 0xffff)
+#define EMAC_RX_IO_DATA_STATUS_CRC_ERR	(1 << 4)
+#define EMAC_RX_IO_DATA_STATUS_LEN_ERR	(3 << 5)
+#define EMAC_RX_IO_DATA_STATUS_OK	(1 << 7)
+#define EMAC_RX_FBC_REG		(0x50)
+#define EMAC_INT_CTL_REG	(0x54)
+#define EMAC_INT_STA_REG	(0x58)
+#define EMAC_MAC_CTL0_REG	(0x5c)
+#define EMAC_MAC_CTL0_RX_FLOW_CTL_EN	(1 << 2)
+#define EMAC_MAC_CTL0_TX_FLOW_CTL_EN	(1 << 3)
+#define EMAC_MAC_CTL0_SOFT_RESET	(1 << 15)
+#define EMAC_MAC_CTL1_REG	(0x60)
+#define EMAC_MAC_CTL1_DUPLEX_EN		(1 << 0)
+#define EMAC_MAC_CTL1_LEN_CHECK_EN	(1 << 1)
+#define EMAC_MAC_CTL1_HUGE_FRAME_EN	(1 << 2)
+#define EMAC_MAC_CTL1_DELAYED_CRC_EN	(1 << 3)
+#define EMAC_MAC_CTL1_CRC_EN		(1 << 4)
+#define EMAC_MAC_CTL1_PAD_EN		(1 << 5)
+#define EMAC_MAC_CTL1_PAD_CRC_EN	(1 << 6)
+#define EMAC_MAC_CTL1_AD_SHORT_FRAME_EN	(1 << 7)
+#define EMAC_MAC_CTL1_BACKOFF_DIS	(1 << 12)
+#define EMAC_MAC_IPGT_REG	(0x64)
+#define EMAC_MAC_IPGT_HALF_DUPLEX	(0x12)
+#define EMAC_MAC_IPGT_FULL_DUPLEX	(0x15)
+#define EMAC_MAC_IPGR_REG	(0x68)
+#define EMAC_MAC_IPGR_IPG1		(0x0c)
+#define EMAC_MAC_IPGR_IPG2		(0x12)
+#define EMAC_MAC_CLRT_REG	(0x6c)
+#define EMAC_MAC_CLRT_COLLISION_WINDOW	(0x37)
+#define EMAC_MAC_CLRT_RM		(0x0f)
+#define EMAC_MAC_MAXF_REG	(0x70)
+#define EMAC_MAC_SUPP_REG	(0x74)
+#define EMAC_MAC_TEST_REG	(0x78)
+#define EMAC_MAC_MCFG_REG	(0x7c)
+#define EMAC_MAC_A0_REG		(0x98)
+#define EMAC_MAC_A1_REG		(0x9c)
+#define EMAC_MAC_A2_REG		(0xa0)
+#define EMAC_SAFX_L_REG0	(0xa4)
+#define EMAC_SAFX_H_REG0	(0xa8)
+#define EMAC_SAFX_L_REG1	(0xac)
+#define EMAC_SAFX_H_REG1	(0xb0)
+#define EMAC_SAFX_L_REG2	(0xb4)
+#define EMAC_SAFX_H_REG2	(0xb8)
+#define EMAC_SAFX_L_REG3	(0xbc)
+#define EMAC_SAFX_H_REG3	(0xc0)
+
+#define EMAC_PHY_DUPLEX		(1 << 8)
+
+#define EMAC_EEPROM_MAGIC	(0x444d394b)
+#define EMAC_UNDOCUMENTED_MAGIC	(0x0143414d)
+#endif /* _SUN4I_EMAC_H_ */
-- 
1.8.1.2

[PATCH 2/6] net: Add MDIO bus driver for the Allwinner EMAC

[Maxime Ripard]

This patch adds a separate driver for the MDIO interface of the
Allwinner ethernet controllers.

Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 .../bindings/net/allwinner,sun4i-mdio.txt          |  26 +++
 drivers/net/ethernet/allwinner/Kconfig             |   8 +
 drivers/net/ethernet/allwinner/Makefile            |   1 +
 drivers/net/ethernet/allwinner/sun4i-mdio.c        | 191 +++++++++++++++++++++
 4 files changed, 226 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/allwinner,sun4i-mdio.txt
 create mode 100644 drivers/net/ethernet/allwinner/sun4i-mdio.c

diff --git a/Documentation/devicetree/bindings/net/allwinner,sun4i-mdio.txt b/Documentation/devicetree/bindings/net/allwinner,sun4i-mdio.txt
new file mode 100644
index 0000000..00b9f9a
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/allwinner,sun4i-mdio.txt
@@ -0,0 +1,26 @@
+* Allwinner A10 MDIO Ethernet Controller interface
+
+Required properties:
+- compatible: should be "allwinner,sun4i-mdio".
+- reg: address and length of the register set for the device.
+
+Optional properties:
+- phy-supply: phandle to a regulator if the PHY needs one
+
+Example at the SoC level:
+mdio@01c0b080 {
+	compatible = "allwinner,sun4i-mdio";
+	reg = <0x01c0b080 0x14>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+};
+
+And at the board level:
+
+mdio@01c0b080 {
+	phy-supply = <&reg_emac_3v3>;
+
+	phy0: ethernet-phy@0 {
+		reg = <0>;
+	};
+};
diff --git a/drivers/net/ethernet/allwinner/Kconfig b/drivers/net/ethernet/allwinner/Kconfig
index 5d20fb0..7bbd500 100644
--- a/drivers/net/ethernet/allwinner/Kconfig
+++ b/drivers/net/ethernet/allwinner/Kconfig
@@ -27,10 +27,18 @@ config SUN4I_EMAC
 	select NET_CORE
 	select MII
 	select REGULATOR_FIXED_VOLTAGE
+	select PHYLIB
         ---help---
           Support for Allwinner A10 EMAC ethernet driver.
 
           To compile this driver as a module, choose M here.  The module
           will be called sun4i-emac.
 
+config SUN4I_MDIO
+	tristate "Allwinner sun4i MDIO interface support"
+	---help---
+	  This driver supports the MDIO interface found in the network
+	  interface units of the Allwinner SoC that have an EMAC (A10,
+	  A12, A10s, etc.)
+
 endif # NET_VENDOR_ALLWINNER
diff --git a/drivers/net/ethernet/allwinner/Makefile b/drivers/net/ethernet/allwinner/Makefile
index 03129f7..95eaa31 100644
--- a/drivers/net/ethernet/allwinner/Makefile
+++ b/drivers/net/ethernet/allwinner/Makefile
@@ -3,3 +3,4 @@
 #
 
 obj-$(CONFIG_SUN4I_EMAC) += sun4i-emac.o
+obj-$(CONFIG_SUN4I_MDIO) += sun4i-mdio.o
\ No newline at end of file
diff --git a/drivers/net/ethernet/allwinner/sun4i-mdio.c b/drivers/net/ethernet/allwinner/sun4i-mdio.c
new file mode 100644
index 0000000..00e432c
--- /dev/null
+++ b/drivers/net/ethernet/allwinner/sun4i-mdio.c
@@ -0,0 +1,191 @@
+/*
+ * Allwinner EMAC MDIO interface driver
+ *
+ * Copyright 2012-2013 Stefan Roese <sr-ynQEQJNshbs@public.gmane.org>
+ * Copyright 2013 Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
+ *
+ * Based on the Linux driver provided by Allwinner:
+ * Copyright (C) 1997  Sten Wang
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_address.h>
+#include <linux/of_mdio.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+
+#define EMAC_MAC_MCMD_REG	(0x00)
+#define EMAC_MAC_MADR_REG	(0x04)
+#define EMAC_MAC_MWTD_REG	(0x08)
+#define EMAC_MAC_MRDD_REG	(0x0c)
+#define EMAC_MAC_MIND_REG	(0x10)
+#define EMAC_MAC_SSRR_REG	(0x14)
+
+#define MDIO_TIMEOUT		(msecs_to_jiffies(100))
+
+struct sun4i_mdio_data {
+	void __iomem		*membase;
+	struct regulator	*regulator;
+};
+
+static int sun4i_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
+{
+	struct sun4i_mdio_data *data = bus->priv;
+	unsigned long start_jiffies;
+	int value;
+
+	/* issue the phy address and reg */
+	writel((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG);
+	/* pull up the phy io line */
+	writel(0x1, data->membase + EMAC_MAC_MCMD_REG);
+
+	/* Wait read complete */
+	start_jiffies = jiffies;
+	while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {
+		if (time_after(start_jiffies,
+			       start_jiffies + MDIO_TIMEOUT))
+			return -ETIMEDOUT;
+		msleep(1);
+	}
+
+	/* push down the phy io line */
+	writel(0x0, data->membase + EMAC_MAC_MCMD_REG);
+	/* and read data */
+	value = readl(data->membase + EMAC_MAC_MRDD_REG);
+
+	return value;
+}
+
+static int sun4i_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
+			    u16 value)
+{
+	struct sun4i_mdio_data *data = bus->priv;
+	unsigned long start_jiffies;
+
+	/* issue the phy address and reg */
+	writel((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG);
+	/* pull up the phy io line */
+	writel(0x1, data->membase + EMAC_MAC_MCMD_REG);
+
+	/* Wait read complete */
+	start_jiffies = jiffies;
+	while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {
+		if (time_after(start_jiffies,
+			       start_jiffies + MDIO_TIMEOUT))
+			return -ETIMEDOUT;
+		msleep(1);
+	}
+
+	/* push down the phy io line */
+	writel(0x0, data->membase + EMAC_MAC_MCMD_REG);
+	/* and write data */
+	writel(value, data->membase + EMAC_MAC_MWTD_REG);
+
+	return 0;
+}
+
+static int sun4i_mdio_reset(struct mii_bus *bus)
+{
+	return 0;
+}
+
+static int sun4i_mdio_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct mii_bus *bus;
+	struct sun4i_mdio_data *data;
+	int ret, i;
+
+	bus = mdiobus_alloc_size(sizeof(*data));
+	if (!bus)
+		return -ENOMEM;
+
+	bus->name = "sun4i_mii_bus";
+	bus->read = &sun4i_mdio_read;
+	bus->write = &sun4i_mdio_write;
+	bus->reset = &sun4i_mdio_reset;
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
+	bus->parent = &pdev->dev;
+
+	bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
+	if (!bus->irq) {
+		ret = -ENOMEM;
+		goto err_out_free_mdiobus;
+	}
+
+	for (i = 0; i < PHY_MAX_ADDR; i++)
+		bus->irq[i] = PHY_POLL;
+
+	data = bus->priv;
+	data->membase = of_iomap(np, 0);
+	if (!data->membase) {
+		ret = -ENOMEM;
+		goto err_out_free_mdio_irq;
+	}
+
+	data->regulator = devm_regulator_get(&pdev->dev, "phy");
+	if (IS_ERR(data->regulator)) {
+		if (PTR_ERR(data->regulator) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+
+		dev_info(&pdev->dev, "no regulator found\n");
+	} else
+		regulator_enable(data->regulator);
+
+	ret = of_mdiobus_register(bus, np);
+	if (ret < 0)
+		goto err_out_disable_regulator;
+
+	platform_set_drvdata(pdev, bus);
+
+	return 0;
+
+err_out_disable_regulator:
+	regulator_disable(data->regulator);
+err_out_free_mdio_irq:
+	kfree(bus->irq);
+err_out_free_mdiobus:
+	mdiobus_free(bus);
+	return ret;
+}
+
+static int sun4i_mdio_remove(struct platform_device *pdev)
+{
+	struct mii_bus *bus = platform_get_drvdata(pdev);
+
+	mdiobus_unregister(bus);
+	kfree(bus->irq);
+	mdiobus_free(bus);
+
+	return 0;
+}
+
+static const struct of_device_id sun4i_mdio_dt_ids[] = {
+	{ .compatible = "allwinner,sun4i-mdio" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sun4i_mdio_dt_ids);
+
+static struct platform_driver sun4i_mdio_driver = {
+	.probe = sun4i_mdio_probe,
+	.remove = sun4i_mdio_remove,
+	.driver = {
+		.name = "sun4i-mdio",
+		.of_match_table = sun4i_mdio_dt_ids,
+	},
+};
+
+module_platform_driver(sun4i_mdio_driver);
+
+MODULE_DESCRIPTION("Allwinner EMAC MDIO interface driver");
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>");
+MODULE_LICENSE("GPL");
-- 
1.8.1.2