net: ethernet: nixge: Add support for National Instruments XGE netdev

Add support for the National Instruments XGE 1/10G network device.

It uses the EEPROM on the board via NVMEM.
Signed-off-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/Kconfig

@@ -129,6 +129,7 @@ config FEALNX
 
 source "drivers/net/ethernet/natsemi/Kconfig"
 source "drivers/net/ethernet/netronome/Kconfig"
+source "drivers/net/ethernet/ni/Kconfig"
 source "drivers/net/ethernet/8390/Kconfig"
 
 config NET_NETX

drivers/net/ethernet/Makefile

@@ -61,6 +61,7 @@ obj-$(CONFIG_NET_VENDOR_MYRI) += myricom/
 obj-$(CONFIG_FEALNX) += fealnx.o
 obj-$(CONFIG_NET_VENDOR_NATSEMI) += natsemi/
 obj-$(CONFIG_NET_VENDOR_NETRONOME) += netronome/
+obj-$(CONFIG_NET_VENDOR_NI) += ni/
 obj-$(CONFIG_NET_NETX) += netx-eth.o
 obj-$(CONFIG_NET_VENDOR_NUVOTON) += nuvoton/
 obj-$(CONFIG_NET_VENDOR_NVIDIA) += nvidia/

drivers/net/ethernet/ni/Kconfig

+#
+# National Instuments network device configuration
+#
+
+config NET_VENDOR_NI
+	bool "National Instruments Devices"
+	default y
+	help
+	  If you have a network (Ethernet) device belonging to this class, say Y.
+
+	  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 National Instrument devices.
+	  If you say Y, you will be asked for your specific device in the
+	  following questions.
+
+if NET_VENDOR_NI
+
+config NI_XGE_MANAGEMENT_ENET
+	tristate "National Instruments XGE management enet support"
+	depends on ARCH_ZYNQ
+	select PHYLIB
+	help
+	  Simple LAN device for debug or management purposes. Can
+	  support either 10G or 1G PHYs via SFP+ ports.
+
+endif

drivers/net/ethernet/ni/Makefile

+obj-$(CONFIG_NI_XGE_MANAGEMENT_ENET) += nixge.o

drivers/net/ethernet/ni/nixge.c

+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2016-2017, National Instruments Corp.
+ *
+ * Author: Moritz Fischer <mdf@kernel.org>
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of_address.h>
+#include <linux/of_mdio.h>
+#include <linux/of_net.h>
+#include <linux/of_platform.h>
+#include <linux/of_irq.h>
+#include <linux/skbuff.h>
+#include <linux/phy.h>
+#include <linux/mii.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/ethtool.h>
+#include <linux/iopoll.h>
+
+#define TX_BD_NUM		64
+#define RX_BD_NUM		128
+
+/* Axi DMA Register definitions */
+#define XAXIDMA_TX_CR_OFFSET	0x00 /* Channel control */
+#define XAXIDMA_TX_SR_OFFSET	0x04 /* Status */
+#define XAXIDMA_TX_CDESC_OFFSET	0x08 /* Current descriptor pointer */
+#define XAXIDMA_TX_TDESC_OFFSET	0x10 /* Tail descriptor pointer */
+
+#define XAXIDMA_RX_CR_OFFSET	0x30 /* Channel control */
+#define XAXIDMA_RX_SR_OFFSET	0x34 /* Status */
+#define XAXIDMA_RX_CDESC_OFFSET	0x38 /* Current descriptor pointer */
+#define XAXIDMA_RX_TDESC_OFFSET	0x40 /* Tail descriptor pointer */
+
+#define XAXIDMA_CR_RUNSTOP_MASK	0x1 /* Start/stop DMA channel */
+#define XAXIDMA_CR_RESET_MASK	0x4 /* Reset DMA engine */
+
+#define XAXIDMA_BD_CTRL_LENGTH_MASK	0x007FFFFF /* Requested len */
+#define XAXIDMA_BD_CTRL_TXSOF_MASK	0x08000000 /* First tx packet */
+#define XAXIDMA_BD_CTRL_TXEOF_MASK	0x04000000 /* Last tx packet */
+#define XAXIDMA_BD_CTRL_ALL_MASK	0x0C000000 /* All control bits */
+
+#define XAXIDMA_DELAY_MASK		0xFF000000 /* Delay timeout counter */
+#define XAXIDMA_COALESCE_MASK		0x00FF0000 /* Coalesce counter */
+
+#define XAXIDMA_DELAY_SHIFT		24
+#define XAXIDMA_COALESCE_SHIFT		16
+
+#define XAXIDMA_IRQ_IOC_MASK		0x00001000 /* Completion intr */
+#define XAXIDMA_IRQ_DELAY_MASK		0x00002000 /* Delay interrupt */
+#define XAXIDMA_IRQ_ERROR_MASK		0x00004000 /* Error interrupt */
+#define XAXIDMA_IRQ_ALL_MASK		0x00007000 /* All interrupts */
+
+/* Default TX/RX Threshold and waitbound values for SGDMA mode */
+#define XAXIDMA_DFT_TX_THRESHOLD	24
+#define XAXIDMA_DFT_TX_WAITBOUND	254
+#define XAXIDMA_DFT_RX_THRESHOLD	24
+#define XAXIDMA_DFT_RX_WAITBOUND	254
+
+#define XAXIDMA_BD_STS_ACTUAL_LEN_MASK	0x007FFFFF /* Actual len */
+#define XAXIDMA_BD_STS_COMPLETE_MASK	0x80000000 /* Completed */
+#define XAXIDMA_BD_STS_DEC_ERR_MASK	0x40000000 /* Decode error */
+#define XAXIDMA_BD_STS_SLV_ERR_MASK	0x20000000 /* Slave error */
+#define XAXIDMA_BD_STS_INT_ERR_MASK	0x10000000 /* Internal err */
+#define XAXIDMA_BD_STS_ALL_ERR_MASK	0x70000000 /* All errors */
+#define XAXIDMA_BD_STS_RXSOF_MASK	0x08000000 /* First rx pkt */
+#define XAXIDMA_BD_STS_RXEOF_MASK	0x04000000 /* Last rx pkt */
+#define XAXIDMA_BD_STS_ALL_MASK		0xFC000000 /* All status bits */
+
+#define NIXGE_REG_CTRL_OFFSET	0x4000
+#define NIXGE_REG_INFO		0x00
+#define NIXGE_REG_MAC_CTL	0x04
+#define NIXGE_REG_PHY_CTL	0x08
+#define NIXGE_REG_LED_CTL	0x0c
+#define NIXGE_REG_MDIO_DATA	0x10
+#define NIXGE_REG_MDIO_ADDR	0x14
+#define NIXGE_REG_MDIO_OP	0x18
+#define NIXGE_REG_MDIO_CTRL	0x1c
+
+#define NIXGE_ID_LED_CTL_EN	BIT(0)
+#define NIXGE_ID_LED_CTL_VAL	BIT(1)
+
+#define NIXGE_MDIO_CLAUSE45	BIT(12)
+#define NIXGE_MDIO_CLAUSE22	0
+#define NIXGE_MDIO_OP(n)     (((n) & 0x3) << 10)
+#define NIXGE_MDIO_OP_ADDRESS	0
+#define NIXGE_MDIO_C45_WRITE	BIT(0)
+#define NIXGE_MDIO_C45_READ	(BIT(1) | BIT(0))
+#define NIXGE_MDIO_C22_WRITE	BIT(0)
+#define NIXGE_MDIO_C22_READ	BIT(1)
+#define NIXGE_MDIO_ADDR(n)   (((n) & 0x1f) << 5)
+#define NIXGE_MDIO_MMD(n)    (((n) & 0x1f) << 0)
+
+#define NIXGE_REG_MAC_LSB	0x1000
+#define NIXGE_REG_MAC_MSB	0x1004
+
+/* Packet size info */
+#define NIXGE_HDR_SIZE		14 /* Size of Ethernet header */
+#define NIXGE_TRL_SIZE		4 /* Size of Ethernet trailer (FCS) */
+#define NIXGE_MTU		1500 /* Max MTU of an Ethernet frame */
+#define NIXGE_JUMBO_MTU		9000 /* Max MTU of a jumbo Eth. frame */
+
+#define NIXGE_MAX_FRAME_SIZE	 (NIXGE_MTU + NIXGE_HDR_SIZE + NIXGE_TRL_SIZE)
+#define NIXGE_MAX_JUMBO_FRAME_SIZE \
+	(NIXGE_JUMBO_MTU + NIXGE_HDR_SIZE + NIXGE_TRL_SIZE)
+
+struct nixge_hw_dma_bd {
+	u32 next;
+	u32 reserved1;
+	u32 phys;
+	u32 reserved2;
+	u32 reserved3;
+	u32 reserved4;
+	u32 cntrl;
+	u32 status;
+	u32 app0;
+	u32 app1;
+	u32 app2;
+	u32 app3;
+	u32 app4;
+	u32 sw_id_offset;
+	u32 reserved5;
+	u32 reserved6;
+};
+
+struct nixge_tx_skb {
+	struct sk_buff *skb;
+	dma_addr_t mapping;
+	size_t size;
+	bool mapped_as_page;
+};
+
+struct nixge_priv {
+	struct net_device *ndev;
+	struct napi_struct napi;
+	struct device *dev;
+
+	/* Connection to PHY device */
+	struct device_node *phy_node;
+	phy_interface_t		phy_mode;
+
+	int link;
+	unsigned int speed;
+	unsigned int duplex;
+
+	/* MDIO bus data */
+	struct mii_bus *mii_bus;	/* MII bus reference */
+
+	/* IO registers, dma functions and IRQs */
+	void __iomem *ctrl_regs;
+	void __iomem *dma_regs;
+
+	struct tasklet_struct dma_err_tasklet;
+
+	int tx_irq;
+	int rx_irq;
+	u32 last_link;
+
+	/* Buffer descriptors */
+	struct nixge_hw_dma_bd *tx_bd_v;
+	struct nixge_tx_skb *tx_skb;
+	dma_addr_t tx_bd_p;
+
+	struct nixge_hw_dma_bd *rx_bd_v;
+	dma_addr_t rx_bd_p;
+	u32 tx_bd_ci;
+	u32 tx_bd_tail;
+	u32 rx_bd_ci;
+
+	u32 coalesce_count_rx;
+	u32 coalesce_count_tx;
+};
+
+static void nixge_dma_write_reg(struct nixge_priv *priv, off_t offset, u32 val)
+{
+	writel(val, priv->dma_regs + offset);
+}
+
+static u32 nixge_dma_read_reg(const struct nixge_priv *priv, off_t offset)
+{
+	return readl(priv->dma_regs + offset);
+}
+
+static void nixge_ctrl_write_reg(struct nixge_priv *priv, off_t offset, u32 val)
+{
+	writel(val, priv->ctrl_regs + offset);
+}
+
+static u32 nixge_ctrl_read_reg(struct nixge_priv *priv, off_t offset)
+{
+	return readl(priv->ctrl_regs + offset);
+}
+
+#define nixge_ctrl_poll_timeout(priv, addr, val, cond, sleep_us, timeout_us) \
+	readl_poll_timeout((priv)->ctrl_regs + (addr), (val), (cond), \
+			   (sleep_us), (timeout_us))
+
+#define nixge_dma_poll_timeout(priv, addr, val, cond, sleep_us, timeout_us) \
+	readl_poll_timeout((priv)->dma_regs + (addr), (val), (cond), \
+			   (sleep_us), (timeout_us))
+
+static void nixge_hw_dma_bd_release(struct net_device *ndev)
+{
+	struct nixge_priv *priv = netdev_priv(ndev);
+	int i;
+
+	for (i = 0; i < RX_BD_NUM; i++) {
+		dma_unmap_single(ndev->dev.parent, priv->rx_bd_v[i].phys,
+				 NIXGE_MAX_JUMBO_FRAME_SIZE, DMA_FROM_DEVICE);
+		dev_kfree_skb((struct sk_buff *)
+			      (priv->rx_bd_v[i].sw_id_offset));
+	}
+
+	if (priv->rx_bd_v)
+		dma_free_coherent(ndev->dev.parent,
+				  sizeof(*priv->rx_bd_v) * RX_BD_NUM,
+				  priv->rx_bd_v,
+				  priv->rx_bd_p);
+
+	if (priv->tx_skb)
+		devm_kfree(ndev->dev.parent, priv->tx_skb);
+
+	if (priv->tx_bd_v)
+		dma_free_coherent(ndev->dev.parent,
+				  sizeof(*priv->tx_bd_v) * TX_BD_NUM,
+				  priv->tx_bd_v,
+				  priv->tx_bd_p);
+}
+
+static int nixge_hw_dma_bd_init(struct net_device *ndev)
+{
+	struct nixge_priv *priv = netdev_priv(ndev);
+	struct sk_buff *skb;
+	u32 cr;
+	int i;
+
+	/* Reset the indexes which are used for accessing the BDs */
+	priv->tx_bd_ci = 0;
+	priv->tx_bd_tail = 0;
+	priv->rx_bd_ci = 0;
+
+	/* Allocate the Tx and Rx buffer descriptors. */
+	priv->tx_bd_v = dma_zalloc_coherent(ndev->dev.parent,
+					    sizeof(*priv->tx_bd_v) * TX_BD_NUM,
+					    &priv->tx_bd_p, GFP_KERNEL);
+	if (!priv->tx_bd_v)
+		goto out;
+
+	priv->tx_skb = devm_kzalloc(ndev->dev.parent,
+				    sizeof(*priv->tx_skb) *
+				    TX_BD_NUM,
+				    GFP_KERNEL);
+	if (!priv->tx_skb)
+		goto out;
+
+	priv->rx_bd_v = dma_zalloc_coherent(ndev->dev.parent,
+					    sizeof(*priv->rx_bd_v) * RX_BD_NUM,
+					    &priv->rx_bd_p, GFP_KERNEL);
+	if (!priv->rx_bd_v)
+		goto out;
+
+	for (i = 0; i < TX_BD_NUM; i++) {
+		priv->tx_bd_v[i].next = priv->tx_bd_p +
+				      sizeof(*priv->tx_bd_v) *
+				      ((i + 1) % TX_BD_NUM);
+	}
+
+	for (i = 0; i < RX_BD_NUM; i++) {
+		priv->rx_bd_v[i].next = priv->rx_bd_p +
+				      sizeof(*priv->rx_bd_v) *
+				      ((i + 1) % RX_BD_NUM);
+
+		skb = netdev_alloc_skb_ip_align(ndev,
+						NIXGE_MAX_JUMBO_FRAME_SIZE);
+		if (!skb)
+			goto out;
+
+		priv->rx_bd_v[i].sw_id_offset = (u32)skb;
+		priv->rx_bd_v[i].phys =
+			dma_map_single(ndev->dev.parent,
+				       skb->data,
+				       NIXGE_MAX_JUMBO_FRAME_SIZE,
+				       DMA_FROM_DEVICE);
+		priv->rx_bd_v[i].cntrl = NIXGE_MAX_JUMBO_FRAME_SIZE;
+	}
+
+	/* Start updating the Rx channel control register */
+	cr = nixge_dma_read_reg(priv, XAXIDMA_RX_CR_OFFSET);
+	/* Update the interrupt coalesce count */
+	cr = ((cr & ~XAXIDMA_COALESCE_MASK) |
+	      ((priv->coalesce_count_rx) << XAXIDMA_COALESCE_SHIFT));
+	/* Update the delay timer count */
+	cr = ((cr & ~XAXIDMA_DELAY_MASK) |
+	      (XAXIDMA_DFT_RX_WAITBOUND << XAXIDMA_DELAY_SHIFT));
+	/* Enable coalesce, delay timer and error interrupts */
+	cr |= XAXIDMA_IRQ_ALL_MASK;
+	/* Write to the Rx channel control register */
+	nixge_dma_write_reg(priv, XAXIDMA_RX_CR_OFFSET, cr);
+
+	/* Start updating the Tx channel control register */
+	cr = nixge_dma_read_reg(priv, XAXIDMA_TX_CR_OFFSET);
+	/* Update the interrupt coalesce count */
+	cr = (((cr & ~XAXIDMA_COALESCE_MASK)) |
+	      ((priv->coalesce_count_tx) << XAXIDMA_COALESCE_SHIFT));
+	/* Update the delay timer count */
+	cr = (((cr & ~XAXIDMA_DELAY_MASK)) |
+	      (XAXIDMA_DFT_TX_WAITBOUND << XAXIDMA_DELAY_SHIFT));
+	/* Enable coalesce, delay timer and error interrupts */
+	cr |= XAXIDMA_IRQ_ALL_MASK;
+	/* Write to the Tx channel control register */
+	nixge_dma_write_reg(priv, XAXIDMA_TX_CR_OFFSET, cr);
+
+	/* Populate the tail pointer and bring the Rx Axi DMA engine out of
+	 * halted state. This will make the Rx side ready for reception.
+	 */
+	nixge_dma_write_reg(priv, XAXIDMA_RX_CDESC_OFFSET, priv->rx_bd_p);
+	cr = nixge_dma_read_reg(priv, XAXIDMA_RX_CR_OFFSET);
+	nixge_dma_write_reg(priv, XAXIDMA_RX_CR_OFFSET,
+			    cr | XAXIDMA_CR_RUNSTOP_MASK);
+	nixge_dma_write_reg(priv, XAXIDMA_RX_TDESC_OFFSET, priv->rx_bd_p +
+			    (sizeof(*priv->rx_bd_v) * (RX_BD_NUM - 1)));
+
+	/* Write to the RS (Run-stop) bit in the Tx channel control register.
+	 * Tx channel is now ready to run. But only after we write to the
+	 * tail pointer register that the Tx channel will start transmitting.
+	 */
+	nixge_dma_write_reg(priv, XAXIDMA_TX_CDESC_OFFSET, priv->tx_bd_p);
+	cr = nixge_dma_read_reg(priv, XAXIDMA_TX_CR_OFFSET);
+	nixge_dma_write_reg(priv, XAXIDMA_TX_CR_OFFSET,
+			    cr | XAXIDMA_CR_RUNSTOP_MASK);
+
+	return 0;
+out:
+	nixge_hw_dma_bd_release(ndev);
+	return -ENOMEM;
+}
+
+static void __nixge_device_reset(struct nixge_priv *priv, off_t offset)
+{
+	u32 status;
+	int err;
+
+	/* Reset Axi DMA. This would reset NIXGE Ethernet core as well.
+	 * The reset process of Axi DMA takes a while to complete as all
+	 * pending commands/transfers will be flushed or completed during
+	 * this reset process.
+	 */
+	nixge_dma_write_reg(priv, offset, XAXIDMA_CR_RESET_MASK);
+	err = nixge_dma_poll_timeout(priv, offset, status,
+				     !(status & XAXIDMA_CR_RESET_MASK), 10,
+				     1000);
+	if (err)
+		netdev_err(priv->ndev, "%s: DMA reset timeout!\n", __func__);
+}
+
+static void nixge_device_reset(struct net_device *ndev)
+{
+	struct nixge_priv *priv = netdev_priv(ndev);
+
+	__nixge_device_reset(priv, XAXIDMA_TX_CR_OFFSET);
+	__nixge_device_reset(priv, XAXIDMA_RX_CR_OFFSET);
+
+	if (nixge_hw_dma_bd_init(ndev))
+		netdev_err(ndev, "%s: descriptor allocation failed\n",
+			   __func__);
+
+	netif_trans_update(ndev);
+}
+
+static void nixge_handle_link_change(struct net_device *ndev)
+{
+	struct nixge_priv *priv = netdev_priv(ndev);
+	struct phy_device *phydev = ndev->phydev;
+
+	if (phydev->link != priv->link || phydev->speed != priv->speed ||
+	    phydev->duplex != priv->duplex) {
+		priv->link = phydev->link;
+		priv->speed = phydev->speed;
+		priv->duplex = phydev->duplex;
+		phy_print_status(phydev);
+	}
+}
+
+static void nixge_tx_skb_unmap(struct nixge_priv *priv,
+			       struct nixge_tx_skb *tx_skb)
+{
+	if (tx_skb->mapping) {
+		if (tx_skb->mapped_as_page)
+			dma_unmap_page(priv->ndev->dev.parent, tx_skb->mapping,
+				       tx_skb->size, DMA_TO_DEVICE);
+		else
+			dma_unmap_single(priv->ndev->dev.parent,
+					 tx_skb->mapping,
+					 tx_skb->size, DMA_TO_DEVICE);
+		tx_skb->mapping = 0;
+	}
+
+	if (tx_skb->skb) {
+		dev_kfree_skb_any(tx_skb->skb);
+		tx_skb->skb = NULL;
+	}
+}
+
+static void nixge_start_xmit_done(struct net_device *ndev)
+{
+	struct nixge_priv *priv = netdev_priv(ndev);
+	struct nixge_hw_dma_bd *cur_p;
+	struct nixge_tx_skb *tx_skb;
+	unsigned int status = 0;
+	u32 packets = 0;
+	u32 size = 0;
+
+	cur_p = &priv->tx_bd_v[priv->tx_bd_ci];
+	tx_skb = &priv->tx_skb[priv->tx_bd_ci];
+
+	status = cur_p->status;
+
+	while (status & XAXIDMA_BD_STS_COMPLETE_MASK) {
+		nixge_tx_skb_unmap(priv, tx_skb);
+		cur_p->status = 0;
+
+		size += status & XAXIDMA_BD_STS_ACTUAL_LEN_MASK;
+		packets++;
+
+		++priv->tx_bd_ci;
+		priv->tx_bd_ci %= TX_BD_NUM;
+		cur_p = &priv->tx_bd_v[priv->tx_bd_ci];
+		tx_skb = &priv->tx_skb[priv->tx_bd_ci];
+		status = cur_p->status;
+	}
+
+	ndev->stats.tx_packets += packets;
+	ndev->stats.tx_bytes += size;
+
+	if (packets)
+		netif_wake_queue(ndev);
+}
+
+static int nixge_check_tx_bd_space(struct nixge_priv *priv,
+				   int num_frag)
+{
+	struct nixge_hw_dma_bd *cur_p;
+
+	cur_p = &priv->tx_bd_v[(priv->tx_bd_tail + num_frag) % TX_BD_NUM];
+	if (cur_p->status & XAXIDMA_BD_STS_ALL_MASK)
+		return NETDEV_TX_BUSY;
+	return 0;
+}
+
+static int nixge_start_xmit(struct sk_buff *skb, struct net_device *ndev)
+{
+	struct nixge_priv *priv = netdev_priv(ndev);
+	struct nixge_hw_dma_bd *cur_p;
+	struct nixge_tx_skb *tx_skb;
+	dma_addr_t tail_p;
+	skb_frag_t *frag;
+	u32 num_frag;
+	u32 ii;
+
+	num_frag = skb_shinfo(skb)->nr_frags;
+	cur_p = &priv->tx_bd_v[priv->tx_bd_tail];
+	tx_skb = &priv->tx_skb[priv->tx_bd_tail];
+
+	if (nixge_check_tx_bd_space(priv, num_frag)) {
+		if (!netif_queue_stopped(ndev))
+			netif_stop_queue(ndev);
+		return NETDEV_TX_OK;
+	}
+
+	cur_p->phys = dma_map_single(ndev->dev.parent, skb->data,
+				     skb_headlen(skb), DMA_TO_DEVICE);
+	if (dma_mapping_error(ndev->dev.parent, cur_p->phys))
+		goto drop;
+
+	cur_p->cntrl = skb_headlen(skb) | XAXIDMA_BD_CTRL_TXSOF_MASK;
+
+	tx_skb->skb = NULL;
+	tx_skb->mapping = cur_p->phys;
+	tx_skb->size = skb_headlen(skb);
+	tx_skb->mapped_as_page = false;
+
+	for (ii = 0; ii < num_frag; ii++) {
+		++priv->tx_bd_tail;
+		priv->tx_bd_tail %= TX_BD_NUM;
+		cur_p = &priv->tx_bd_v[priv->tx_bd_tail];
+		tx_skb = &priv->tx_skb[priv->tx_bd_tail];
+		frag = &skb_shinfo(skb)->frags[ii];
+
+		cur_p->phys = skb_frag_dma_map(ndev->dev.parent, frag, 0,
+					       skb_frag_size(frag),
+					       DMA_TO_DEVICE);
+		if (dma_mapping_error(ndev->dev.parent, cur_p->phys))
+			goto frag_err;
+
+		cur_p->cntrl = skb_frag_size(frag);
+
+		tx_skb->skb = NULL;
+		tx_skb->mapping = cur_p->phys;
+		tx_skb->size = skb_frag_size(frag);
+		tx_skb->mapped_as_page = true;
+	}
+
+	/* last buffer of the frame */
+	tx_skb->skb = skb;
+
+	cur_p->cntrl |= XAXIDMA_BD_CTRL_TXEOF_MASK;
+	cur_p->app4 = (unsigned long)skb;
+
+	tail_p = priv->tx_bd_p + sizeof(*priv->tx_bd_v) * priv->tx_bd_tail;
+	/* Start the transfer */
+	nixge_dma_write_reg(priv, XAXIDMA_TX_TDESC_OFFSET, tail_p);
+	++priv->tx_bd_tail;
+	priv->tx_bd_tail %= TX_BD_NUM;
+
+	return NETDEV_TX_OK;
+frag_err:
+	for (; ii > 0; ii--) {
+		if (priv->tx_bd_tail)
+			priv->tx_bd_tail--;
+		else
+			priv->tx_bd_tail = TX_BD_NUM - 1;
+
+		tx_skb = &priv->tx_skb[priv->tx_bd_tail];
+		nixge_tx_skb_unmap(priv, tx_skb);
+
+		cur_p = &priv->tx_bd_v[priv->tx_bd_tail];
+		cur_p->status = 0;
+	}
+	dma_unmap_single(priv->ndev->dev.parent,
+			 tx_skb->mapping,
+			 tx_skb->size, DMA_TO_DEVICE);
+drop:
+	ndev->stats.tx_dropped++;
+	return NETDEV_TX_OK;
+}
+
+static int nixge_recv(struct net_device *ndev, int budget)
+{
+	struct nixge_priv *priv = netdev_priv(ndev);
+	struct sk_buff *skb, *new_skb;
+	struct nixge_hw_dma_bd *cur_p;
+	dma_addr_t tail_p = 0;
+	u32 packets = 0;
+	u32 length = 0;
+	u32 size = 0;
+
+	cur_p = &priv->rx_bd_v[priv->rx_bd_ci];
+
+	while ((cur_p->status & XAXIDMA_BD_STS_COMPLETE_MASK &&
+		budget > packets)) {
+		tail_p = priv->rx_bd_p + sizeof(*priv->rx_bd_v) *
+			 priv->rx_bd_ci;
+
+		skb = (struct sk_buff *)(cur_p->sw_id_offset);
+
+		length = cur_p->status & XAXIDMA_BD_STS_ACTUAL_LEN_MASK;
+		if (length > NIXGE_MAX_JUMBO_FRAME_SIZE)
+			length = NIXGE_MAX_JUMBO_FRAME_SIZE;
+
+		dma_unmap_single(ndev->dev.parent, cur_p->phys,
+				 NIXGE_MAX_JUMBO_FRAME_SIZE,
+				 DMA_FROM_DEVICE);
+
+		skb_put(skb, length);
+
+		skb->protocol = eth_type_trans(skb, ndev);
+		skb_checksum_none_assert(skb);
+
+		/* For now mark them as CHECKSUM_NONE since
+		 * we don't have offload capabilities
+		 */
+		skb->ip_summed = CHECKSUM_NONE;
+
+		napi_gro_receive(&priv->napi, skb);
+
+		size += length;
+		packets++;
+
+		new_skb = netdev_alloc_skb_ip_align(ndev,
+						    NIXGE_MAX_JUMBO_FRAME_SIZE);
+		if (!new_skb)
+			return packets;
+
+		cur_p->phys = dma_map_single(ndev->dev.parent, new_skb->data,
+					     NIXGE_MAX_JUMBO_FRAME_SIZE,
+					     DMA_FROM_DEVICE);
+		if (dma_mapping_error(ndev->dev.parent, cur_p->phys)) {
+			/* FIXME: bail out and clean up */
+			netdev_err(ndev, "Failed to map ...\n");
+		}
+		cur_p->cntrl = NIXGE_MAX_JUMBO_FRAME_SIZE;
+		cur_p->status = 0;
+		cur_p->sw_id_offset = (u32)new_skb;
+
+		++priv->rx_bd_ci;
+		priv->rx_bd_ci %= RX_BD_NUM;
+		cur_p = &priv->rx_bd_v[priv->rx_bd_ci];
+	}
+
+	ndev->stats.rx_packets += packets;
+	ndev->stats.rx_bytes += size;
+
+	if (tail_p)
+		nixge_dma_write_reg(priv, XAXIDMA_RX_TDESC_OFFSET, tail_p);
+
+	return packets;
+}
+
+static int nixge_poll(struct napi_struct *napi, int budget)
+{
+	struct nixge_priv *priv = container_of(napi, struct nixge_priv, napi);
+	int work_done;
+	u32 status, cr;
+
+	work_done = 0;
+
+	work_done = nixge_recv(priv->ndev, budget);
+	if (work_done < budget) {
+		napi_complete_done(napi, work_done);
+		status = nixge_dma_read_reg(priv, XAXIDMA_RX_SR_OFFSET);
+
+		if (status & (XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK)) {
+			/* If there's more, reschedule, but clear */
+			nixge_dma_write_reg(priv, XAXIDMA_RX_SR_OFFSET, status);
+			napi_reschedule(napi);
+		} else {
+			/* if not, turn on RX IRQs again ... */
+			cr = nixge_dma_read_reg(priv, XAXIDMA_RX_CR_OFFSET);
+			cr |= (XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK);
+			nixge_dma_write_reg(priv, XAXIDMA_RX_CR_OFFSET, cr);
+		}
+	}
+
+	return work_done;
+}
+
+static irqreturn_t nixge_tx_irq(int irq, void *_ndev)
+{
+	struct nixge_priv *priv = netdev_priv(_ndev);
+	struct net_device *ndev = _ndev;
+	unsigned int status;
+	u32 cr;
+
+	status = nixge_dma_read_reg(priv, XAXIDMA_TX_SR_OFFSET);
+	if (status & (XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK)) {
+		nixge_dma_write_reg(priv, XAXIDMA_TX_SR_OFFSET, status);
+		nixge_start_xmit_done(priv->ndev);
+		goto out;
+	}
+	if (!(status & XAXIDMA_IRQ_ALL_MASK)) {
+		netdev_err(ndev, "No interrupts asserted in Tx path\n");
+		return IRQ_NONE;
+	}
+	if (status & XAXIDMA_IRQ_ERROR_MASK) {
+		netdev_err(ndev, "DMA Tx error 0x%x\n", status);
+		netdev_err(ndev, "Current BD is at: 0x%x\n",
+			   (priv->tx_bd_v[priv->tx_bd_ci]).phys);
+
+		cr = nixge_dma_read_reg(priv, XAXIDMA_TX_CR_OFFSET);
+		/* Disable coalesce, delay timer and error interrupts */
+		cr &= (~XAXIDMA_IRQ_ALL_MASK);
+		/* Write to the Tx channel control register */
+		nixge_dma_write_reg(priv, XAXIDMA_TX_CR_OFFSET, cr);
+
+		cr = nixge_dma_read_reg(priv, XAXIDMA_RX_CR_OFFSET);
+		/* Disable coalesce, delay timer and error interrupts */
+		cr &= (~XAXIDMA_IRQ_ALL_MASK);
+		/* Write to the Rx channel control register */
+		nixge_dma_write_reg(priv, XAXIDMA_RX_CR_OFFSET, cr);
+
+		tasklet_schedule(&priv->dma_err_tasklet);
+		nixge_dma_write_reg(priv, XAXIDMA_TX_SR_OFFSET, status);
+	}
+out:
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t nixge_rx_irq(int irq, void *_ndev)
+{
+	struct nixge_priv *priv = netdev_priv(_ndev);
+	struct net_device *ndev = _ndev;
+	unsigned int status;
+	u32 cr;
+
+	status = nixge_dma_read_reg(priv, XAXIDMA_RX_SR_OFFSET);
+	if (status & (XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK)) {
+		/* Turn of IRQs because NAPI */
+		nixge_dma_write_reg(priv, XAXIDMA_RX_SR_OFFSET, status);
+		cr = nixge_dma_read_reg(priv, XAXIDMA_RX_CR_OFFSET);
+		cr &= ~(XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK);
+		nixge_dma_write_reg(priv, XAXIDMA_RX_CR_OFFSET, cr);
+
+		if (napi_schedule_prep(&priv->napi))
+			__napi_schedule(&priv->napi);
+		goto out;
+	}
+	if (!(status & XAXIDMA_IRQ_ALL_MASK)) {
+		netdev_err(ndev, "No interrupts asserted in Rx path\n");
+		return IRQ_NONE;
+	}
+	if (status & XAXIDMA_IRQ_ERROR_MASK) {
+		netdev_err(ndev, "DMA Rx error 0x%x\n", status);
+		netdev_err(ndev, "Current BD is at: 0x%x\n",
+			   (priv->rx_bd_v[priv->rx_bd_ci]).phys);
+
+		cr = nixge_dma_read_reg(priv, XAXIDMA_TX_CR_OFFSET);
+		/* Disable coalesce, delay timer and error interrupts */
+		cr &= (~XAXIDMA_IRQ_ALL_MASK);
+		/* Finally write to the Tx channel control register */
+		nixge_dma_write_reg(priv, XAXIDMA_TX_CR_OFFSET, cr);
+
+		cr = nixge_dma_read_reg(priv, XAXIDMA_RX_CR_OFFSET);
+		/* Disable coalesce, delay timer and error interrupts */
+		cr &= (~XAXIDMA_IRQ_ALL_MASK);
+		/* write to the Rx channel control register */
+		nixge_dma_write_reg(priv, XAXIDMA_RX_CR_OFFSET, cr);
+
+		tasklet_schedule(&priv->dma_err_tasklet);
+		nixge_dma_write_reg(priv, XAXIDMA_RX_SR_OFFSET, status);
+	}
+out:
+	return IRQ_HANDLED;
+}
+
+static void nixge_dma_err_handler(unsigned long data)
+{
+	struct nixge_priv *lp = (struct nixge_priv *)data;
+	struct nixge_hw_dma_bd *cur_p;
+	struct nixge_tx_skb *tx_skb;
+	u32 cr, i;
+
+	__nixge_device_reset(lp, XAXIDMA_TX_CR_OFFSET);
+	__nixge_device_reset(lp, XAXIDMA_RX_CR_OFFSET);
+
+	for (i = 0; i < TX_BD_NUM; i++) {
+		cur_p = &lp->tx_bd_v[i];
+		tx_skb = &lp->tx_skb[i];
+		nixge_tx_skb_unmap(lp, tx_skb);
+
+		cur_p->phys = 0;
+		cur_p->cntrl = 0;
+		cur_p->status = 0;
+		cur_p->app0 = 0;
+		cur_p->app1 = 0;
+		cur_p->app2 = 0;
+		cur_p->app3 = 0;
+		cur_p->app4 = 0;
+		cur_p->sw_id_offset = 0;
+	}
+
+	for (i = 0; i < RX_BD_NUM; i++) {
+		cur_p = &lp->rx_bd_v[i];
+		cur_p->status = 0;
+		cur_p->app0 = 0;
+		cur_p->app1 = 0;
+		cur_p->app2 = 0;
+		cur_p->app3 = 0;
+		cur_p->app4 = 0;
+	}
+
+	lp->tx_bd_ci = 0;
+	lp->tx_bd_tail = 0;
+	lp->rx_bd_ci = 0;
+
+	/* Start updating the Rx channel control register */
+	cr = nixge_dma_read_reg(lp, XAXIDMA_RX_CR_OFFSET);
+	/* Update the interrupt coalesce count */
+	cr = ((cr & ~XAXIDMA_COALESCE_MASK) |
+	      (XAXIDMA_DFT_RX_THRESHOLD << XAXIDMA_COALESCE_SHIFT));
+	/* Update the delay timer count */
+	cr = ((cr & ~XAXIDMA_DELAY_MASK) |
+	      (XAXIDMA_DFT_RX_WAITBOUND << XAXIDMA_DELAY_SHIFT));
+	/* Enable coalesce, delay timer and error interrupts */
+	cr |= XAXIDMA_IRQ_ALL_MASK;
+	/* Finally write to the Rx channel control register */
+	nixge_dma_write_reg(lp, XAXIDMA_RX_CR_OFFSET, cr);
+
+	/* Start updating the Tx channel control register */
+	cr = nixge_dma_read_reg(lp, XAXIDMA_TX_CR_OFFSET);
+	/* Update the interrupt coalesce count */
+	cr = (((cr & ~XAXIDMA_COALESCE_MASK)) |
+	      (XAXIDMA_DFT_TX_THRESHOLD << XAXIDMA_COALESCE_SHIFT));
+	/* Update the delay timer count */
+	cr = (((cr & ~XAXIDMA_DELAY_MASK)) |
+	      (XAXIDMA_DFT_TX_WAITBOUND << XAXIDMA_DELAY_SHIFT));
+	/* Enable coalesce, delay timer and error interrupts */
+	cr |= XAXIDMA_IRQ_ALL_MASK;
+	/* Finally write to the Tx channel control register */
+	nixge_dma_write_reg(lp, XAXIDMA_TX_CR_OFFSET, cr);
+
+	/* Populate the tail pointer and bring the Rx Axi DMA engine out of
+	 * halted state. This will make the Rx side ready for reception.
+	 */
+	nixge_dma_write_reg(lp, XAXIDMA_RX_CDESC_OFFSET, lp->rx_bd_p);
+	cr = nixge_dma_read_reg(lp, XAXIDMA_RX_CR_OFFSET);
+	nixge_dma_write_reg(lp, XAXIDMA_RX_CR_OFFSET,
+			    cr | XAXIDMA_CR_RUNSTOP_MASK);
+	nixge_dma_write_reg(lp, XAXIDMA_RX_TDESC_OFFSET, lp->rx_bd_p +
+			    (sizeof(*lp->rx_bd_v) * (RX_BD_NUM - 1)));
+
+	/* Write to the RS (Run-stop) bit in the Tx channel control register.
+	 * Tx channel is now ready to run. But only after we write to the
+	 * tail pointer register that the Tx channel will start transmitting
+	 */
+	nixge_dma_write_reg(lp, XAXIDMA_TX_CDESC_OFFSET, lp->tx_bd_p);
+	cr = nixge_dma_read_reg(lp, XAXIDMA_TX_CR_OFFSET);
+	nixge_dma_write_reg(lp, XAXIDMA_TX_CR_OFFSET,
+			    cr | XAXIDMA_CR_RUNSTOP_MASK);
+}
+
+static int nixge_open(struct net_device *ndev)
+{
+	struct nixge_priv *priv = netdev_priv(ndev);
+	struct phy_device *phy;
+	int ret;
+
+	nixge_device_reset(ndev);
+
+	phy = of_phy_connect(ndev, priv->phy_node,
+			     &nixge_handle_link_change, 0, priv->phy_mode);
+	if (!phy)
+		return -ENODEV;
+
+	phy_start(phy);
+
+	/* Enable tasklets for Axi DMA error handling */
+	tasklet_init(&priv->dma_err_tasklet, nixge_dma_err_handler,
+		     (unsigned long)priv);
+
+	napi_enable(&priv->napi);
+
+	/* Enable interrupts for Axi DMA Tx */
+	ret = request_irq(priv->tx_irq, nixge_tx_irq, 0, ndev->name, ndev);
+	if (ret)
+		goto err_tx_irq;
+	/* Enable interrupts for Axi DMA Rx */
+	ret = request_irq(priv->rx_irq, nixge_rx_irq, 0, ndev->name, ndev);
+	if (ret)
+		goto err_rx_irq;
+
+	netif_start_queue(ndev);
+
+	return 0;
+
+err_rx_irq:
+	free_irq(priv->tx_irq, ndev);
+err_tx_irq:
+	phy_stop(phy);
+	phy_disconnect(phy);
+	tasklet_kill(&priv->dma_err_tasklet);
+	netdev_err(ndev, "request_irq() failed\n");
+	return ret;
+}
+
+static int nixge_stop(struct net_device *ndev)
+{
+	struct nixge_priv *priv = netdev_priv(ndev);
+	u32 cr;
+
+	netif_stop_queue(ndev);
+	napi_disable(&priv->napi);
+
+	if (ndev->phydev) {
+		phy_stop(ndev->phydev);
+		phy_disconnect(ndev->phydev);
+	}
+
+	cr = nixge_dma_read_reg(priv, XAXIDMA_RX_CR_OFFSET);
+	nixge_dma_write_reg(priv, XAXIDMA_RX_CR_OFFSET,
+			    cr & (~XAXIDMA_CR_RUNSTOP_MASK));
+	cr = nixge_dma_read_reg(priv, XAXIDMA_TX_CR_OFFSET);
+	nixge_dma_write_reg(priv, XAXIDMA_TX_CR_OFFSET,
+			    cr & (~XAXIDMA_CR_RUNSTOP_MASK));
+
+	tasklet_kill(&priv->dma_err_tasklet);
+
+	free_irq(priv->tx_irq, ndev);
+	free_irq(priv->rx_irq, ndev);
+
+	nixge_hw_dma_bd_release(ndev);
+
+	return 0;
+}
+
+static int nixge_change_mtu(struct net_device *ndev, int new_mtu)
+{
+	if (netif_running(ndev))
+		return -EBUSY;
+
+	if ((new_mtu + NIXGE_HDR_SIZE + NIXGE_TRL_SIZE) >
+	     NIXGE_MAX_JUMBO_FRAME_SIZE)
+		return -EINVAL;
+
+	ndev->mtu = new_mtu;
+
+	return 0;
+}
+
+static s32 __nixge_hw_set_mac_address(struct net_device *ndev)
+{
+	struct nixge_priv *priv = netdev_priv(ndev);
+
+	nixge_ctrl_write_reg(priv, NIXGE_REG_MAC_LSB,
+			     (ndev->dev_addr[2]) << 24 |
+			     (ndev->dev_addr[3] << 16) |
+			     (ndev->dev_addr[4] << 8) |
+			     (ndev->dev_addr[5] << 0));
+
+	nixge_ctrl_write_reg(priv, NIXGE_REG_MAC_MSB,
+			     (ndev->dev_addr[1] | (ndev->dev_addr[0] << 8)));
+
+	return 0;
+}
+
+static int nixge_net_set_mac_address(struct net_device *ndev, void *p)
+{
+	int err;
+
+	err = eth_mac_addr(ndev, p);
+	if (!err)
+		__nixge_hw_set_mac_address(ndev);
+
+	return err;
+}
+
+static const struct net_device_ops nixge_netdev_ops = {
+	.ndo_open = nixge_open,
+	.ndo_stop = nixge_stop,
+	.ndo_start_xmit = nixge_start_xmit,
+	.ndo_change_mtu	= nixge_change_mtu,
+	.ndo_set_mac_address = nixge_net_set_mac_address,
+	.ndo_validate_addr = eth_validate_addr,
+};
+
+static void nixge_ethtools_get_drvinfo(struct net_device *ndev,
+				       struct ethtool_drvinfo *ed)
+{
+	strlcpy(ed->driver, "nixge", sizeof(ed->driver));
+	strlcpy(ed->bus_info, "platform", sizeof(ed->driver));
+}
+
+static int nixge_ethtools_get_coalesce(struct net_device *ndev,
+				       struct ethtool_coalesce *ecoalesce)
+{
+	struct nixge_priv *priv = netdev_priv(ndev);
+	u32 regval = 0;
+
+	regval = nixge_dma_read_reg(priv, XAXIDMA_RX_CR_OFFSET);
+	ecoalesce->rx_max_coalesced_frames = (regval & XAXIDMA_COALESCE_MASK)
+					     >> XAXIDMA_COALESCE_SHIFT;
+	regval = nixge_dma_read_reg(priv, XAXIDMA_TX_CR_OFFSET);
+	ecoalesce->tx_max_coalesced_frames = (regval & XAXIDMA_COALESCE_MASK)
+					     >> XAXIDMA_COALESCE_SHIFT;
+	return 0;
+}
+
+static int nixge_ethtools_set_coalesce(struct net_device *ndev,
+				       struct ethtool_coalesce *ecoalesce)
+{
+	struct nixge_priv *priv = netdev_priv(ndev);
+
+	if (netif_running(ndev)) {
+		netdev_err(ndev,
+			   "Please stop netif before applying configuration\n");
+		return -EBUSY;
+	}
+
+	if (ecoalesce->rx_coalesce_usecs ||
+	    ecoalesce->rx_coalesce_usecs_irq ||
+	    ecoalesce->rx_max_coalesced_frames_irq ||
+	    ecoalesce->tx_coalesce_usecs ||
+	    ecoalesce->tx_coalesce_usecs_irq ||
+	    ecoalesce->tx_max_coalesced_frames_irq ||
+	    ecoalesce->stats_block_coalesce_usecs ||
+	    ecoalesce->use_adaptive_rx_coalesce ||
+	    ecoalesce->use_adaptive_tx_coalesce ||
+	    ecoalesce->pkt_rate_low ||
+	    ecoalesce->rx_coalesce_usecs_low ||
+	    ecoalesce->rx_max_coalesced_frames_low ||
+	    ecoalesce->tx_coalesce_usecs_low ||
+	    ecoalesce->tx_max_coalesced_frames_low ||
+	    ecoalesce->pkt_rate_high ||
+	    ecoalesce->rx_coalesce_usecs_high ||
+	    ecoalesce->rx_max_coalesced_frames_high ||
+	    ecoalesce->tx_coalesce_usecs_high ||
+	    ecoalesce->tx_max_coalesced_frames_high ||
+	    ecoalesce->rate_sample_interval)
+		return -EOPNOTSUPP;
+	if (ecoalesce->rx_max_coalesced_frames)
+		priv->coalesce_count_rx = ecoalesce->rx_max_coalesced_frames;
+	if (ecoalesce->tx_max_coalesced_frames)
+		priv->coalesce_count_tx = ecoalesce->tx_max_coalesced_frames;
+
+	return 0;
+}
+
+static int nixge_ethtools_set_phys_id(struct net_device *ndev,
+				      enum ethtool_phys_id_state state)
+{
+	struct nixge_priv *priv = netdev_priv(ndev);
+	u32 ctrl;
+
+	ctrl = nixge_ctrl_read_reg(priv, NIXGE_REG_LED_CTL);
+	switch (state) {
+	case ETHTOOL_ID_ACTIVE:
+		ctrl |= NIXGE_ID_LED_CTL_EN;
+		/* Enable identification LED override*/
+		nixge_ctrl_write_reg(priv, NIXGE_REG_LED_CTL, ctrl);
+		return 2;
+
+	case ETHTOOL_ID_ON:
+		ctrl |= NIXGE_ID_LED_CTL_VAL;
+		nixge_ctrl_write_reg(priv, NIXGE_REG_LED_CTL, ctrl);
+		break;
+
+	case ETHTOOL_ID_OFF:
+		ctrl &= ~NIXGE_ID_LED_CTL_VAL;
+		nixge_ctrl_write_reg(priv, NIXGE_REG_LED_CTL, ctrl);
+		break;
+
+	case ETHTOOL_ID_INACTIVE:
+		/* Restore LED settings */
+		ctrl &= ~NIXGE_ID_LED_CTL_EN;
+		nixge_ctrl_write_reg(priv, NIXGE_REG_LED_CTL, ctrl);
+		break;
+	}
+
+	return 0;
+}
+
+static const struct ethtool_ops nixge_ethtool_ops = {
+	.get_drvinfo    = nixge_ethtools_get_drvinfo,
+	.get_coalesce   = nixge_ethtools_get_coalesce,
+	.set_coalesce   = nixge_ethtools_set_coalesce,
+	.set_phys_id    = nixge_ethtools_set_phys_id,
+	.get_link_ksettings     = phy_ethtool_get_link_ksettings,
+	.set_link_ksettings     = phy_ethtool_set_link_ksettings,
+	.get_link		= ethtool_op_get_link,
+};
+
+static int nixge_mdio_read(struct mii_bus *bus, int phy_id, int reg)
+{
+	struct nixge_priv *priv = bus->priv;
+	u32 status, tmp;
+	int err;
+	u16 device;
+
+	if (reg & MII_ADDR_C45) {
+		device = (reg >> 16) & 0x1f;
+
+		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_ADDR, reg & 0xffff);
+
+		tmp = NIXGE_MDIO_CLAUSE45 | NIXGE_MDIO_OP(NIXGE_MDIO_OP_ADDRESS)
+			| NIXGE_MDIO_ADDR(phy_id) | NIXGE_MDIO_MMD(device);
+
+		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_OP, tmp);
+		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_CTRL, 1);
+
+		err = nixge_ctrl_poll_timeout(priv, NIXGE_REG_MDIO_CTRL, status,
+					      !status, 10, 1000);
+		if (err) {
+			dev_err(priv->dev, "timeout setting address");
+			return err;
+		}
+
+		tmp = NIXGE_MDIO_CLAUSE45 | NIXGE_MDIO_OP(NIXGE_MDIO_C45_READ) |
+			NIXGE_MDIO_ADDR(phy_id) | NIXGE_MDIO_MMD(device);
+	} else {
+		device = reg & 0x1f;
+
+		tmp = NIXGE_MDIO_CLAUSE22 | NIXGE_MDIO_OP(NIXGE_MDIO_C22_READ) |
+			NIXGE_MDIO_ADDR(phy_id) | NIXGE_MDIO_MMD(device);
+	}
+
+	nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_OP, tmp);
+	nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_CTRL, 1);
+
+	err = nixge_ctrl_poll_timeout(priv, NIXGE_REG_MDIO_CTRL, status,
+				      !status, 10, 1000);
+	if (err) {
+		dev_err(priv->dev, "timeout setting read command");
+		return err;
+	}
+
+	status = nixge_ctrl_read_reg(priv, NIXGE_REG_MDIO_DATA);
+
+	return status;
+}
+
+static int nixge_mdio_write(struct mii_bus *bus, int phy_id, int reg, u16 val)
+{
+	struct nixge_priv *priv = bus->priv;
+	u32 status, tmp;
+	u16 device;
+	int err;
+
+	if (reg & MII_ADDR_C45) {
+		device = (reg >> 16) & 0x1f;
+
+		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_ADDR, reg & 0xffff);
+
+		tmp = NIXGE_MDIO_CLAUSE45 | NIXGE_MDIO_OP(NIXGE_MDIO_OP_ADDRESS)
+			| NIXGE_MDIO_ADDR(phy_id) | NIXGE_MDIO_MMD(device);
+
+		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_OP, tmp);
+		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_CTRL, 1);
+
+		err = nixge_ctrl_poll_timeout(priv, NIXGE_REG_MDIO_CTRL, status,
+					      !status, 10, 1000);
+		if (err) {
+			dev_err(priv->dev, "timeout setting address");
+			return err;
+		}
+
+		tmp = NIXGE_MDIO_CLAUSE45 | NIXGE_MDIO_OP(NIXGE_MDIO_C45_WRITE)
+			| NIXGE_MDIO_ADDR(phy_id) | NIXGE_MDIO_MMD(device);
+
+		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_DATA, val);
+		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_OP, tmp);
+		err = nixge_ctrl_poll_timeout(priv, NIXGE_REG_MDIO_CTRL, status,
+					      !status, 10, 1000);
+		if (err)
+			dev_err(priv->dev, "timeout setting write command");
+	} else {
+		device = reg & 0x1f;
+
+		tmp = NIXGE_MDIO_CLAUSE22 |
+			NIXGE_MDIO_OP(NIXGE_MDIO_C22_WRITE) |
+			NIXGE_MDIO_ADDR(phy_id) | NIXGE_MDIO_MMD(device);
+
+		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_DATA, val);
+		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_OP, tmp);
+		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_CTRL, 1);
+
+		err = nixge_ctrl_poll_timeout(priv, NIXGE_REG_MDIO_CTRL, status,
+					      !status, 10, 1000);
+		if (err)
+			dev_err(priv->dev, "timeout setting write command");
+	}
+
+	return err;
+}
+
+static int nixge_mdio_setup(struct nixge_priv *priv, struct device_node *np)
+{
+	struct mii_bus *bus;
+
+	bus = devm_mdiobus_alloc(priv->dev);
+	if (!bus)
+		return -ENOMEM;
+
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(priv->dev));
+	bus->priv = priv;
+	bus->name = "nixge_mii_bus";
+	bus->read = nixge_mdio_read;
+	bus->write = nixge_mdio_write;
+	bus->parent = priv->dev;
+
+	priv->mii_bus = bus;
+
+	return of_mdiobus_register(bus, np);
+}
+
+static void *nixge_get_nvmem_address(struct device *dev)
+{
+	struct nvmem_cell *cell;
+	size_t cell_size;
+	char *mac;
+
+	cell = nvmem_cell_get(dev, "address");
+	if (IS_ERR(cell))
+		return cell;
+
+	mac = nvmem_cell_read(cell, &cell_size);
+	nvmem_cell_put(cell);
+
+	return mac;
+}
+
+static int nixge_probe(struct platform_device *pdev)
+{
+	struct nixge_priv *priv;
+	struct net_device *ndev;
+	struct resource *dmares;
+	const char *mac_addr;
+	int err;
+
+	ndev = alloc_etherdev(sizeof(*priv));
+	if (!ndev)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, ndev);
+	SET_NETDEV_DEV(ndev, &pdev->dev);
+
+	ndev->features = NETIF_F_SG;
+	ndev->netdev_ops = &nixge_netdev_ops;
+	ndev->ethtool_ops = &nixge_ethtool_ops;
+
+	/* MTU range: 64 - 9000 */
+	ndev->min_mtu = 64;
+	ndev->max_mtu = NIXGE_JUMBO_MTU;
+
+	mac_addr = nixge_get_nvmem_address(&pdev->dev);
+	if (mac_addr && is_valid_ether_addr(mac_addr))
+		ether_addr_copy(ndev->dev_addr, mac_addr);
+	else
+		eth_hw_addr_random(ndev);
+
+	priv = netdev_priv(ndev);
+	priv->ndev = ndev;
+	priv->dev = &pdev->dev;
+
+	netif_napi_add(ndev, &priv->napi, nixge_poll, NAPI_POLL_WEIGHT);
+
+	dmares = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	priv->dma_regs = devm_ioremap_resource(&pdev->dev, dmares);
+	if (IS_ERR(priv->dma_regs)) {
+		netdev_err(ndev, "failed to map dma regs\n");
+		return PTR_ERR(priv->dma_regs);
+	}
+	priv->ctrl_regs = priv->dma_regs + NIXGE_REG_CTRL_OFFSET;
+	__nixge_hw_set_mac_address(ndev);
+
+	priv->tx_irq = platform_get_irq_byname(pdev, "tx");
+	if (priv->tx_irq < 0) {
+		netdev_err(ndev, "could not find 'tx' irq");
+		return priv->tx_irq;
+	}
+
+	priv->rx_irq = platform_get_irq_byname(pdev, "rx");
+	if (priv->rx_irq < 0) {
+		netdev_err(ndev, "could not find 'rx' irq");
+		return priv->rx_irq;
+	}
+
+	priv->coalesce_count_rx = XAXIDMA_DFT_RX_THRESHOLD;
+	priv->coalesce_count_tx = XAXIDMA_DFT_TX_THRESHOLD;
+
+	err = nixge_mdio_setup(priv, pdev->dev.of_node);
+	if (err) {
+		netdev_err(ndev, "error registering mdio bus");
+		goto free_netdev;
+	}
+
+	priv->phy_mode = of_get_phy_mode(pdev->dev.of_node);
+	if (priv->phy_mode < 0) {
+		netdev_err(ndev, "not find \"phy-mode\" property\n");
+		err = -EINVAL;
+		goto unregister_mdio;
+	}
+
+	priv->phy_node = of_parse_phandle(pdev->dev.of_node, "phy-handle", 0);
+	if (!priv->phy_node) {
+		netdev_err(ndev, "not find \"phy-handle\" property\n");
+		err = -EINVAL;
+		goto unregister_mdio;
+	}
+
+	err = register_netdev(priv->ndev);
+	if (err) {
+		netdev_err(ndev, "register_netdev() error (%i)\n", err);
+		goto unregister_mdio;
+	}
+
+	return 0;
+
+unregister_mdio:
+	mdiobus_unregister(priv->mii_bus);
+
+free_netdev:
+	free_netdev(ndev);
+
+	return err;
+}
+
+static int nixge_remove(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct nixge_priv *priv = netdev_priv(ndev);
+
+	unregister_netdev(ndev);
+
+	mdiobus_unregister(priv->mii_bus);
+
+	free_netdev(ndev);
+
+	return 0;
+}
+
+/* Match table for of_platform binding */
+static const struct of_device_id nixge_dt_ids[] = {
+	{ .compatible = "ni,xge-enet-2.00", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, nixge_dt_ids);
+
+static struct platform_driver nixge_driver = {
+	.probe		= nixge_probe,
+	.remove		= nixge_remove,
+	.driver		= {
+		.name		= "nixge",
+		.of_match_table	= of_match_ptr(nixge_dt_ids),
+	},
+};
+module_platform_driver(nixge_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("National Instruments XGE Management MAC");
+MODULE_AUTHOR("Moritz Fischer <mdf@kernel.org>");