net: Add Aeroflex Gaisler 10/100/1G Ethernet MAC driver

Adds device driver for Aeroflex Gaisler 10/100 and 10/100/1G Ethernet
MAC IP cores.

Signed-off-by: Kristoffer Glembo <kristoffer@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1645 insertions, 0 deletions

diff --git a/drivers/net/greth.c b/drivers/net/greth.c
new file mode 100644
index 000000000000..457da1c2383c
--- /dev/null
+++ b/drivers/net/greth.c
@@ -0,0 +1,1645 @@
+/*
+ * Aeroflex Gaisler GRETH 10/100/1G Ethernet MAC.
+ *
+ * 2005-2009 (c) Aeroflex Gaisler AB
+ *
+ * This driver supports GRETH 10/100 and GRETH 10/100/1G Ethernet MACs
+ * available in the GRLIB VHDL IP core library.
+ *
+ * Full documentation of both cores can be found here:
+ * http://www.gaisler.com/products/grlib/grip.pdf
+ *
+ * The Gigabit version supports scatter/gather DMA, any alignment of
+ * buffers and checksum offloading.
+ *
+ * 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.
+ *
+ * Contributors: Kristoffer Glembo
+ *               Daniel Hellstrom
+ *               Marko Isomaki
+ */
+
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/skbuff.h>
+#include <linux/io.h>
+#include <linux/crc32.h>
+#include <linux/mii.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <asm/cacheflush.h>
+#include <asm/byteorder.h>
+
+#ifdef CONFIG_SPARC
+#include <asm/idprom.h>
+#endif
+
+#include "greth.h"
+
+#define GRETH_DEF_MSG_ENABLE	  \
+	(NETIF_MSG_DRV		| \
+	 NETIF_MSG_PROBE	| \
+	 NETIF_MSG_LINK		| \
+	 NETIF_MSG_IFDOWN	| \
+	 NETIF_MSG_IFUP		| \
+	 NETIF_MSG_RX_ERR	| \
+	 NETIF_MSG_TX_ERR)
+
+static int greth_debug = -1;	/* -1 == use GRETH_DEF_MSG_ENABLE as value */
+module_param(greth_debug, int, 0);
+MODULE_PARM_DESC(greth_debug, "GRETH bitmapped debugging message enable value");
+
+/* Accept MAC address of the form macaddr=0x08,0x00,0x20,0x30,0x40,0x50 */
+static int macaddr[6];
+module_param_array(macaddr, int, NULL, 0);
+MODULE_PARM_DESC(macaddr, "GRETH Ethernet MAC address");
+
+static int greth_edcl = 1;
+module_param(greth_edcl, int, 0);
+MODULE_PARM_DESC(greth_edcl, "GRETH EDCL usage indicator. Set to 1 if EDCL is used.");
+
+static int greth_open(struct net_device *dev);
+static int greth_start_xmit(struct sk_buff *skb, struct net_device *dev);
+static int greth_start_xmit_gbit(struct sk_buff *skb, struct net_device *dev);
+static int greth_rx(struct net_device *dev, int limit);
+static int greth_rx_gbit(struct net_device *dev, int limit);
+static void greth_clean_tx(struct net_device *dev);
+static void greth_clean_tx_gbit(struct net_device *dev);
+static irqreturn_t greth_interrupt(int irq, void *dev_id);
+static int greth_close(struct net_device *dev);
+static int greth_set_mac_add(struct net_device *dev, void *p);
+static void greth_set_multicast_list(struct net_device *dev);
+
+#define GRETH_REGLOAD(a)	    (be32_to_cpu(__raw_readl(&(a))))
+#define GRETH_REGSAVE(a, v)         (__raw_writel(cpu_to_be32(v), &(a)))
+#define GRETH_REGORIN(a, v)         (GRETH_REGSAVE(a, (GRETH_REGLOAD(a) | (v))))
+#define GRETH_REGANDIN(a, v)        (GRETH_REGSAVE(a, (GRETH_REGLOAD(a) & (v))))
+
+#define NEXT_TX(N)      (((N) + 1) & GRETH_TXBD_NUM_MASK)
+#define SKIP_TX(N, C)   (((N) + C) & GRETH_TXBD_NUM_MASK)
+#define NEXT_RX(N)      (((N) + 1) & GRETH_RXBD_NUM_MASK)
+
+static void greth_print_rx_packet(void *addr, int len)
+{
+	print_hex_dump(KERN_DEBUG, "RX: ", DUMP_PREFIX_OFFSET, 16, 1,
+			addr, len, true);
+}
+
+static void greth_print_tx_packet(struct sk_buff *skb)
+{
+	int i;
+	int length;
+
+	if (skb_shinfo(skb)->nr_frags == 0)
+		length = skb->len;
+	else
+		length = skb_headlen(skb);
+
+	print_hex_dump(KERN_DEBUG, "TX: ", DUMP_PREFIX_OFFSET, 16, 1,
+			skb->data, length, true);
+
+	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+
+		print_hex_dump(KERN_DEBUG, "TX: ", DUMP_PREFIX_OFFSET, 16, 1,
+			       phys_to_virt(page_to_phys(skb_shinfo(skb)->frags[i].page)) +
+			       skb_shinfo(skb)->frags[i].page_offset,
+			       length, true);
+	}
+}
+
+static inline void greth_enable_tx(struct greth_private *greth)
+{
+	wmb();
+	GRETH_REGORIN(greth->regs->control, GRETH_TXEN);
+}
+
+static inline void greth_disable_tx(struct greth_private *greth)
+{
+	GRETH_REGANDIN(greth->regs->control, ~GRETH_TXEN);
+}
+
+static inline void greth_enable_rx(struct greth_private *greth)
+{
+	wmb();
+	GRETH_REGORIN(greth->regs->control, GRETH_RXEN);
+}
+
+static inline void greth_disable_rx(struct greth_private *greth)
+{
+	GRETH_REGANDIN(greth->regs->control, ~GRETH_RXEN);
+}
+
+static inline void greth_enable_irqs(struct greth_private *greth)
+{
+	GRETH_REGORIN(greth->regs->control, GRETH_RXI | GRETH_TXI);
+}
+
+static inline void greth_disable_irqs(struct greth_private *greth)
+{
+	GRETH_REGANDIN(greth->regs->control, ~(GRETH_RXI|GRETH_TXI));
+}
+
+static inline void greth_write_bd(u32 *bd, u32 val)
+{
+	__raw_writel(cpu_to_be32(val), bd);
+}
+
+static inline u32 greth_read_bd(u32 *bd)
+{
+	return be32_to_cpu(__raw_readl(bd));
+}
+
+static void greth_clean_rings(struct greth_private *greth)
+{
+	int i;
+	struct greth_bd *rx_bdp = greth->rx_bd_base;
+	struct greth_bd *tx_bdp = greth->tx_bd_base;
+
+	if (greth->gbit_mac) {
+
+		/* Free and unmap RX buffers */
+		for (i = 0; i < GRETH_RXBD_NUM; i++, rx_bdp++) {
+			if (greth->rx_skbuff[i] != NULL) {
+				dev_kfree_skb(greth->rx_skbuff[i]);
+				dma_unmap_single(greth->dev,
+						 greth_read_bd(&rx_bdp->addr),
+						 MAX_FRAME_SIZE+NET_IP_ALIGN,
+						 DMA_FROM_DEVICE);
+			}
+		}
+
+		/* TX buffers */
+		while (greth->tx_free < GRETH_TXBD_NUM) {
+
+			struct sk_buff *skb = greth->tx_skbuff[greth->tx_last];
+			int nr_frags = skb_shinfo(skb)->nr_frags;
+			tx_bdp = greth->tx_bd_base + greth->tx_last;
+			greth->tx_last = NEXT_TX(greth->tx_last);
+
+			dma_unmap_single(greth->dev,
+					 greth_read_bd(&tx_bdp->addr),
+					 skb_headlen(skb),
+					 DMA_TO_DEVICE);
+
+			for (i = 0; i < nr_frags; i++) {
+				skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+				tx_bdp = greth->tx_bd_base + greth->tx_last;
+
+				dma_unmap_page(greth->dev,
+					       greth_read_bd(&tx_bdp->addr),
+					       frag->size,
+					       DMA_TO_DEVICE);
+
+				greth->tx_last = NEXT_TX(greth->tx_last);
+			}
+			greth->tx_free += nr_frags+1;
+			dev_kfree_skb(skb);
+		}
+
+
+	} else { /* 10/100 Mbps MAC */
+
+		for (i = 0; i < GRETH_RXBD_NUM; i++, rx_bdp++) {
+			kfree(greth->rx_bufs[i]);
+			dma_unmap_single(greth->dev,
+					 greth_read_bd(&rx_bdp->addr),
+					 MAX_FRAME_SIZE,
+					 DMA_FROM_DEVICE);
+		}
+		for (i = 0; i < GRETH_TXBD_NUM; i++, tx_bdp++) {
+			kfree(greth->tx_bufs[i]);
+			dma_unmap_single(greth->dev,
+					 greth_read_bd(&tx_bdp->addr),
+					 MAX_FRAME_SIZE,
+					 DMA_TO_DEVICE);
+		}
+	}
+}
+
+static int greth_init_rings(struct greth_private *greth)
+{
+	struct sk_buff *skb;
+	struct greth_bd *rx_bd, *tx_bd;
+	u32 dma_addr;
+	int i;
+
+	rx_bd = greth->rx_bd_base;
+	tx_bd = greth->tx_bd_base;
+
+	/* Initialize descriptor rings and buffers */
+	if (greth->gbit_mac) {
+
+		for (i = 0; i < GRETH_RXBD_NUM; i++) {
+			skb = netdev_alloc_skb(greth->netdev, MAX_FRAME_SIZE+NET_IP_ALIGN);
+			if (skb == NULL) {
+				if (netif_msg_ifup(greth))
+					dev_err(greth->dev, "Error allocating DMA ring.\n");
+				goto cleanup;
+			}
+			skb_reserve(skb, NET_IP_ALIGN);
+			dma_addr = dma_map_single(greth->dev,
+						  skb->data,
+						  MAX_FRAME_SIZE+NET_IP_ALIGN,
+						  DMA_FROM_DEVICE);
+
+			if (dma_mapping_error(greth->dev, dma_addr)) {
+				if (netif_msg_ifup(greth))
+					dev_err(greth->dev, "Could not create initial DMA mapping\n");
+				goto cleanup;
+			}
+			greth->rx_skbuff[i] = skb;
+			greth_write_bd(&rx_bd[i].addr, dma_addr);
+			greth_write_bd(&rx_bd[i].stat, GRETH_BD_EN | GRETH_BD_IE);
+		}
+
+	} else {
+
+		/* 10/100 MAC uses a fixed set of buffers and copy to/from SKBs */
+		for (i = 0; i < GRETH_RXBD_NUM; i++) {
+
+			greth->rx_bufs[i] = kmalloc(MAX_FRAME_SIZE, GFP_KERNEL);
+
+			if (greth->rx_bufs[i] == NULL) {
+				if (netif_msg_ifup(greth))
+					dev_err(greth->dev, "Error allocating DMA ring.\n");
+				goto cleanup;
+			}
+
+			dma_addr = dma_map_single(greth->dev,
+						  greth->rx_bufs[i],
+						  MAX_FRAME_SIZE,
+						  DMA_FROM_DEVICE);
+
+			if (dma_mapping_error(greth->dev, dma_addr)) {
+				if (netif_msg_ifup(greth))
+					dev_err(greth->dev, "Could not create initial DMA mapping\n");
+				goto cleanup;
+			}
+			greth_write_bd(&rx_bd[i].addr, dma_addr);
+			greth_write_bd(&rx_bd[i].stat, GRETH_BD_EN | GRETH_BD_IE);
+		}
+		for (i = 0; i < GRETH_TXBD_NUM; i++) {
+
+			greth->tx_bufs[i] = kmalloc(MAX_FRAME_SIZE, GFP_KERNEL);
+
+			if (greth->tx_bufs[i] == NULL) {
+				if (netif_msg_ifup(greth))
+					dev_err(greth->dev, "Error allocating DMA ring.\n");
+				goto cleanup;
+			}
+
+			dma_addr = dma_map_single(greth->dev,
+						  greth->tx_bufs[i],
+						  MAX_FRAME_SIZE,
+						  DMA_TO_DEVICE);
+
+			if (dma_mapping_error(greth->dev, dma_addr)) {
+				if (netif_msg_ifup(greth))
+					dev_err(greth->dev, "Could not create initial DMA mapping\n");
+				goto cleanup;
+			}
+			greth_write_bd(&tx_bd[i].addr, dma_addr);
+			greth_write_bd(&tx_bd[i].stat, 0);
+		}
+	}
+	greth_write_bd(&rx_bd[GRETH_RXBD_NUM - 1].stat,
+		       greth_read_bd(&rx_bd[GRETH_RXBD_NUM - 1].stat) | GRETH_BD_WR);
+
+	/* Initialize pointers. */
+	greth->rx_cur = 0;
+	greth->tx_next = 0;
+	greth->tx_last = 0;
+	greth->tx_free = GRETH_TXBD_NUM;
+
+	/* Initialize descriptor base address */
+	GRETH_REGSAVE(greth->regs->tx_desc_p, greth->tx_bd_base_phys);
+	GRETH_REGSAVE(greth->regs->rx_desc_p, greth->rx_bd_base_phys);
+
+	return 0;
+
+cleanup:
+	greth_clean_rings(greth);
+	return -ENOMEM;
+}
+
+static int greth_open(struct net_device *dev)
+{
+	struct greth_private *greth = netdev_priv(dev);
+	int err;
+
+	err = greth_init_rings(greth);
+	if (err) {
+		if (netif_msg_ifup(greth))
+			dev_err(&dev->dev, "Could not allocate memory for DMA rings\n");
+		return err;
+	}
+
+	err = request_irq(greth->irq, greth_interrupt, 0, "eth", (void *) dev);
+	if (err) {
+		if (netif_msg_ifup(greth))
+			dev_err(&dev->dev, "Could not allocate interrupt %d\n", dev->irq);
+		greth_clean_rings(greth);
+		return err;
+	}
+
+	if (netif_msg_ifup(greth))
+		dev_dbg(&dev->dev, " starting queue\n");
+	netif_start_queue(dev);
+
+	napi_enable(&greth->napi);
+
+	greth_enable_irqs(greth);
+	greth_enable_tx(greth);
+	greth_enable_rx(greth);
+	return 0;
+
+}
+
+static int greth_close(struct net_device *dev)
+{
+	struct greth_private *greth = netdev_priv(dev);
+
+	napi_disable(&greth->napi);
+
+	greth_disable_tx(greth);
+
+	netif_stop_queue(dev);
+
+	free_irq(greth->irq, (void *) dev);
+
+	greth_clean_rings(greth);
+
+	return 0;
+}
+
+static int greth_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct greth_private *greth = netdev_priv(dev);
+	struct greth_bd *bdp;
+	int err = NETDEV_TX_OK;
+	u32 status, dma_addr;
+
+	bdp = greth->tx_bd_base + greth->tx_next;
+
+	if (unlikely(greth->tx_free <= 0)) {
+		netif_stop_queue(dev);
+		return NETDEV_TX_BUSY;
+	}
+
+	if (netif_msg_pktdata(greth))
+		greth_print_tx_packet(skb);
+
+
+	if (unlikely(skb->len > MAX_FRAME_SIZE)) {
+		dev->stats.tx_errors++;
+		goto out;
+	}
+
+	dma_addr = greth_read_bd(&bdp->addr);
+
+	memcpy((unsigned char *) phys_to_virt(dma_addr), skb->data, skb->len);
+
+	dma_sync_single_for_device(greth->dev, dma_addr, skb->len, DMA_TO_DEVICE);
+
+	status = GRETH_BD_EN | (skb->len & GRETH_BD_LEN);
+
+	/* Wrap around descriptor ring */
+	if (greth->tx_next == GRETH_TXBD_NUM_MASK) {
+		status |= GRETH_BD_WR;
+	}
+
+	greth->tx_next = NEXT_TX(greth->tx_next);
+	greth->tx_free--;
+
+	/* No more descriptors */
+	if (unlikely(greth->tx_free == 0)) {
+
+		/* Free transmitted descriptors */
+		greth_clean_tx(dev);
+
+		/* If nothing was cleaned, stop queue & wait for irq */
+		if (unlikely(greth->tx_free == 0)) {
+			status |= GRETH_BD_IE;
+			netif_stop_queue(dev);
+		}
+	}
+
+	/* Write descriptor control word and enable transmission */
+	greth_write_bd(&bdp->stat, status);
+	greth_enable_tx(greth);
+
+out:
+	dev_kfree_skb(skb);
+	return err;
+}
+
+
+static int greth_start_xmit_gbit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct greth_private *greth = netdev_priv(dev);
+	struct greth_bd *bdp;
+	u32 status = 0, dma_addr;
+	int curr_tx, nr_frags, i, err = NETDEV_TX_OK;
+
+	nr_frags = skb_shinfo(skb)->nr_frags;
+
+	if (greth->tx_free < nr_frags + 1) {
+		netif_stop_queue(dev);
+		err = NETDEV_TX_BUSY;
+		goto out;
+	}
+
+	if (netif_msg_pktdata(greth))
+		greth_print_tx_packet(skb);
+
+	if (unlikely(skb->len > MAX_FRAME_SIZE)) {
+		dev->stats.tx_errors++;
+		goto out;
+	}
+
+	/* Save skb pointer. */
+	greth->tx_skbuff[greth->tx_next] = skb;
+
+	/* Linear buf */
+	if (nr_frags != 0)
+		status = GRETH_TXBD_MORE;
+
+	status |= GRETH_TXBD_CSALL;
+	status |= skb_headlen(skb) & GRETH_BD_LEN;
+	if (greth->tx_next == GRETH_TXBD_NUM_MASK)
+		status |= GRETH_BD_WR;
+
+
+	bdp = greth->tx_bd_base + greth->tx_next;
+	greth_write_bd(&bdp->stat, status);
+	dma_addr = dma_map_single(greth->dev, skb->data, skb_headlen(skb), DMA_TO_DEVICE);
+
+	if (unlikely(dma_mapping_error(greth->dev, dma_addr)))
+		goto map_error;
+
+	greth_write_bd(&bdp->addr, dma_addr);
+
+	curr_tx = NEXT_TX(greth->tx_next);
+
+	/* Frags */
+	for (i = 0; i < nr_frags; i++) {
+		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+		greth->tx_skbuff[curr_tx] = NULL;
+		bdp = greth->tx_bd_base + curr_tx;
+
+		status = GRETH_TXBD_CSALL;
+		status |= frag->size & GRETH_BD_LEN;
+
+		/* Wrap around descriptor ring */
+		if (curr_tx == GRETH_TXBD_NUM_MASK)
+			status |= GRETH_BD_WR;
+
+		/* More fragments left */
+		if (i < nr_frags - 1)
+			status |= GRETH_TXBD_MORE;
+
+		/* ... last fragment, check if out of descriptors  */
+		else if (greth->tx_free - nr_frags - 1 < (MAX_SKB_FRAGS + 1)) {
+
+			/* Enable interrupts and stop queue */
+			status |= GRETH_BD_IE;
+			netif_stop_queue(dev);
+		}
+
+		greth_write_bd(&bdp->stat, status);
+
+		dma_addr = dma_map_page(greth->dev,
+					frag->page,
+					frag->page_offset,
+					frag->size,
+					DMA_TO_DEVICE);
+
+		if (unlikely(dma_mapping_error(greth->dev, dma_addr)))
+			goto frag_map_error;
+
+		greth_write_bd(&bdp->addr, dma_addr);
+
+		curr_tx = NEXT_TX(curr_tx);
+	}
+
+	wmb();
+
+	/* Enable the descriptors that we configured ...  */
+	for (i = 0; i < nr_frags + 1; i++) {
+		bdp = greth->tx_bd_base + greth->tx_next;
+		greth_write_bd(&bdp->stat, greth_read_bd(&bdp->stat) | GRETH_BD_EN);
+		greth->tx_next = NEXT_TX(greth->tx_next);
+		greth->tx_free--;
+	}
+
+	greth_enable_tx(greth);
+
+	return NETDEV_TX_OK;
+
+frag_map_error:
+	/* Unmap SKB mappings that succeeded */
+	for (i = 0; greth->tx_next + i != curr_tx; i++) {
+		bdp = greth->tx_bd_base + greth->tx_next + i;
+		dma_unmap_single(greth->dev,
+				 greth_read_bd(&bdp->addr),
+				 greth_read_bd(&bdp->stat) & GRETH_BD_LEN,
+				 DMA_TO_DEVICE);
+	}
+map_error:
+	if (net_ratelimit())
+		dev_warn(greth->dev, "Could not create TX DMA mapping\n");
+	dev_kfree_skb(skb);
+	return NETDEV_TX_OK;
+
+out:
+	return err;
+}
+
+
+static irqreturn_t greth_interrupt(int irq, void *dev_id)
+{
+	struct net_device *dev = dev_id;
+	struct greth_private *greth;
+	u32 status;
+	irqreturn_t retval = IRQ_NONE;
+
+	greth = netdev_priv(dev);
+
+	spin_lock(&greth->devlock);
+
+	/* Get the interrupt events that caused us to be here. */
+	status = GRETH_REGLOAD(greth->regs->status);
+
+	/* Handle rx and tx interrupts through poll */
+	if (status & (GRETH_INT_RX | GRETH_INT_TX)) {
+
+		/* Clear interrupt status */
+		GRETH_REGORIN(greth->regs->status,
+			      status & (GRETH_INT_RX | GRETH_INT_TX));
+
+		retval = IRQ_HANDLED;
+
+		/* Disable interrupts and schedule poll() */
+		greth_disable_irqs(greth);
+		napi_schedule(&greth->napi);
+	}
+
+	mmiowb();
+	spin_unlock(&greth->devlock);
+
+	return retval;
+}
+
+static void greth_clean_tx(struct net_device *dev)
+{
+	struct greth_private *greth;
+	struct greth_bd *bdp;
+	u32 stat;
+
+	greth = netdev_priv(dev);
+
+	while (1) {
+		bdp = greth->tx_bd_base + greth->tx_last;
+		stat = greth_read_bd(&bdp->stat);
+
+		if (unlikely(stat & GRETH_BD_EN))
+			break;
+
+		if (greth->tx_free == GRETH_TXBD_NUM)
+			break;
+
+		/* Check status for errors */
+		if (unlikely(stat & GRETH_TXBD_STATUS)) {
+			dev->stats.tx_errors++;
+			if (stat & GRETH_TXBD_ERR_AL)
+				dev->stats.tx_aborted_errors++;
+			if (stat & GRETH_TXBD_ERR_UE)
+				dev->stats.tx_fifo_errors++;
+		}
+		dev->stats.tx_packets++;
+		greth->tx_last = NEXT_TX(greth->tx_last);
+		greth->tx_free++;
+	}
+
+	if (greth->tx_free > 0) {
+		netif_wake_queue(dev);
+	}
+
+}
+
+static inline void greth_update_tx_stats(struct net_device *dev, u32 stat)
+{
+	/* Check status for errors */
+	if (unlikely(stat & GRETH_TXBD_STATUS)) {
+		dev->stats.tx_errors++;
+		if (stat & GRETH_TXBD_ERR_AL)
+			dev->stats.tx_aborted_errors++;
+		if (stat & GRETH_TXBD_ERR_UE)
+			dev->stats.tx_fifo_errors++;
+		if (stat & GRETH_TXBD_ERR_LC)
+			dev->stats.tx_aborted_errors++;
+	}
+	dev->stats.tx_packets++;
+}
+
+static void greth_clean_tx_gbit(struct net_device *dev)
+{
+	struct greth_private *greth;
+	struct greth_bd *bdp, *bdp_last_frag;
+	struct sk_buff *skb;
+	u32 stat;
+	int nr_frags, i;
+
+	greth = netdev_priv(dev);
+
+	while (greth->tx_free < GRETH_TXBD_NUM) {
+
+		skb = greth->tx_skbuff[greth->tx_last];
+
+		nr_frags = skb_shinfo(skb)->nr_frags;
+
+		/* We only clean fully completed SKBs */
+		bdp_last_frag = greth->tx_bd_base + SKIP_TX(greth->tx_last, nr_frags);
+		stat = bdp_last_frag->stat;
+
+		if (stat & GRETH_BD_EN)
+			break;
+
+		greth->tx_skbuff[greth->tx_last] = NULL;
+
+		greth_update_tx_stats(dev, stat);
+
+		bdp = greth->tx_bd_base + greth->tx_last;
+
+		greth->tx_last = NEXT_TX(greth->tx_last);
+
+		dma_unmap_single(greth->dev,
+				 greth_read_bd(&bdp->addr),
+				 skb_headlen(skb),
+				 DMA_TO_DEVICE);
+
+		for (i = 0; i < nr_frags; i++) {
+			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+			bdp = greth->tx_bd_base + greth->tx_last;
+
+			dma_unmap_page(greth->dev,
+				       greth_read_bd(&bdp->addr),
+				       frag->size,
+				       DMA_TO_DEVICE);
+
+			greth->tx_last = NEXT_TX(greth->tx_last);
+		}
+		greth->tx_free += nr_frags+1;
+		dev_kfree_skb(skb);
+	}
+	if (greth->tx_free > (MAX_SKB_FRAGS + 1)) {
+		netif_wake_queue(dev);
+	}
+}
+
+static int greth_pending_packets(struct greth_private *greth)
+{
+	struct greth_bd *bdp;
+	u32 status;
+	bdp = greth->rx_bd_base + greth->rx_cur;
+	status = greth_read_bd(&bdp->stat);
+	if (status & GRETH_BD_EN)
+		return 0;
+	else
+		return 1;
+}
+
+static int greth_rx(struct net_device *dev, int limit)
+{
+	struct greth_private *greth;
+	struct greth_bd *bdp;
+	struct sk_buff *skb;
+	int pkt_len;
+	int bad, count;
+	u32 status, dma_addr;
+
+	greth = netdev_priv(dev);
+
+	for (count = 0; count < limit; ++count) {
+
+		bdp = greth->rx_bd_base + greth->rx_cur;
+		status = greth_read_bd(&bdp->stat);
+		dma_addr = greth_read_bd(&bdp->addr);
+		bad = 0;
+
+		if (unlikely(status & GRETH_BD_EN)) {
+			break;
+		}
+
+		/* Check status for errors. */
+		if (unlikely(status & GRETH_RXBD_STATUS)) {
+			if (status & GRETH_RXBD_ERR_FT) {
+				dev->stats.rx_length_errors++;
+				bad = 1;
+			}
+			if (status & (GRETH_RXBD_ERR_AE | GRETH_RXBD_ERR_OE)) {
+				dev->stats.rx_frame_errors++;
+				bad = 1;
+			}
+			if (status & GRETH_RXBD_ERR_CRC) {
+				dev->stats.rx_crc_errors++;
+				bad = 1;
+			}
+		}
+		if (unlikely(bad)) {
+			dev->stats.rx_errors++;
+
+		} else {
+
+			pkt_len = status & GRETH_BD_LEN;
+
+			skb = netdev_alloc_skb(dev, pkt_len + NET_IP_ALIGN);
+
+			if (unlikely(skb == NULL)) {
+
+				if (net_ratelimit())
+					dev_warn(&dev->dev, "low on memory - " "packet dropped\n");
+
+				dev->stats.rx_dropped++;
+
+			} else {
+				skb_reserve(skb, NET_IP_ALIGN);
+				skb->dev = dev;
+
+				dma_sync_single_for_cpu(greth->dev,
+							dma_addr,
+							pkt_len,
+							DMA_FROM_DEVICE);
+
+				if (netif_msg_pktdata(greth))
+					greth_print_rx_packet(phys_to_virt(dma_addr), pkt_len);
+
+				memcpy(skb_put(skb, pkt_len), phys_to_virt(dma_addr), pkt_len);
+
+				skb->protocol = eth_type_trans(skb, dev);
+				dev->stats.rx_packets++;
+				netif_receive_skb(skb);
+			}
+		}
+
+		status = GRETH_BD_EN | GRETH_BD_IE;
+		if (greth->rx_cur == GRETH_RXBD_NUM_MASK) {
+			status |= GRETH_BD_WR;
+		}
+
+		wmb();
+		greth_write_bd(&bdp->stat, status);
+
+		dma_sync_single_for_device(greth->dev, dma_addr, MAX_FRAME_SIZE, DMA_FROM_DEVICE);
+
+		greth_enable_rx(greth);
+
+		greth->rx_cur = NEXT_RX(greth->rx_cur);
+	}
+
+	return count;
+}
+
+static inline int hw_checksummed(u32 status)
+{
+
+	if (status & GRETH_RXBD_IP_FRAG)
+		return 0;
+
+	if (status & GRETH_RXBD_IP && status & GRETH_RXBD_IP_CSERR)
+		return 0;
+
+	if (status & GRETH_RXBD_UDP && status & GRETH_RXBD_UDP_CSERR)
+		return 0;
+
+	if (status & GRETH_RXBD_TCP && status & GRETH_RXBD_TCP_CSERR)
+		return 0;
+
+	return 1;
+}
+
+static int greth_rx_gbit(struct net_device *dev, int limit)
+{
+	struct greth_private *greth;
+	struct greth_bd *bdp;
+	struct sk_buff *skb, *newskb;
+	int pkt_len;
+	int bad, count = 0;
+	u32 status, dma_addr;
+
+	greth = netdev_priv(dev);
+
+	for (count = 0; count < limit; ++count) {
+
+		bdp = greth->rx_bd_base + greth->rx_cur;
+		skb = greth->rx_skbuff[greth->rx_cur];
+		status = greth_read_bd(&bdp->stat);
+		bad = 0;
+
+		if (status & GRETH_BD_EN)
+			break;
+
+		/* Check status for errors. */
+		if (unlikely(status & GRETH_RXBD_STATUS)) {
+
+			if (status & GRETH_RXBD_ERR_FT) {
+				dev->stats.rx_length_errors++;
+				bad = 1;
+			} else if (status &
+				   (GRETH_RXBD_ERR_AE | GRETH_RXBD_ERR_OE | GRETH_RXBD_ERR_LE)) {
+				dev->stats.rx_frame_errors++;
+				bad = 1;
+			} else if (status & GRETH_RXBD_ERR_CRC) {
+				dev->stats.rx_crc_errors++;
+				bad = 1;
+			}
+		}
+
+		/* Allocate new skb to replace current */
+		newskb = netdev_alloc_skb(dev, MAX_FRAME_SIZE + NET_IP_ALIGN);
+
+		if (!bad && newskb) {
+			skb_reserve(newskb, NET_IP_ALIGN);
+
+			dma_addr = dma_map_single(greth->dev,
+						      newskb->data,
+						      MAX_FRAME_SIZE + NET_IP_ALIGN,
+						      DMA_FROM_DEVICE);
+
+			if (!dma_mapping_error(greth->dev, dma_addr)) {
+				/* Process the incoming frame. */
+				pkt_len = status & GRETH_BD_LEN;
+
+				dma_unmap_single(greth->dev,
+						 greth_read_bd(&bdp->addr),
+						 MAX_FRAME_SIZE + NET_IP_ALIGN,
+						 DMA_FROM_DEVICE);
+
+				if (netif_msg_pktdata(greth))
+					greth_print_rx_packet(phys_to_virt(greth_read_bd(&bdp->addr)), pkt_len);
+
+				skb_put(skb, pkt_len);
+
+				if (greth->flags & GRETH_FLAG_RX_CSUM && hw_checksummed(status))
+					skb->ip_summed = CHECKSUM_UNNECESSARY;
+				else
+					skb->ip_summed = CHECKSUM_NONE;
+
+				skb->dev = dev;
+				skb->protocol = eth_type_trans(skb, dev);
+				dev->stats.rx_packets++;
+				netif_receive_skb(skb);
+
+				greth->rx_skbuff[greth->rx_cur] = newskb;
+				greth_write_bd(&bdp->addr, dma_addr);
+			} else {
+				if (net_ratelimit())
+					dev_warn(greth->dev, "Could not create DMA mapping, dropping packet\n");
+				dev_kfree_skb(newskb);
+				dev->stats.rx_dropped++;
+			}
+		} else {
+			if (net_ratelimit())
+				dev_warn(greth->dev, "Could not allocate SKB, dropping packet\n");
+			dev->stats.rx_dropped++;
+		}
+
+		status = GRETH_BD_EN | GRETH_BD_IE;
+		if (greth->rx_cur == GRETH_RXBD_NUM_MASK) {
+			status |= GRETH_BD_WR;
+		}
+
+		wmb();
+		greth_write_bd(&bdp->stat, status);
+		greth_enable_rx(greth);
+		greth->rx_cur = NEXT_RX(greth->rx_cur);
+	}
+
+	return count;
+
+}
+
+static int greth_poll(struct napi_struct *napi, int budget)
+{
+	struct greth_private *greth;
+	int work_done = 0;
+	greth = container_of(napi, struct greth_private, napi);
+
+	if (greth->gbit_mac) {
+		greth_clean_tx_gbit(greth->netdev);
+	} else {
+		greth_clean_tx(greth->netdev);
+	}
+
+restart_poll:
+	if (greth->gbit_mac) {
+		work_done += greth_rx_gbit(greth->netdev, budget - work_done);
+	} else {
+		work_done += greth_rx(greth->netdev, budget - work_done);
+	}
+
+	if (work_done < budget) {
+
+		napi_complete(napi);
+
+		if (greth_pending_packets(greth)) {
+			napi_reschedule(napi);
+			goto restart_poll;
+		}
+	}
+
+	greth_enable_irqs(greth);
+	return work_done;
+}
+
+static int greth_set_mac_add(struct net_device *dev, void *p)
+{
+	struct sockaddr *addr = p;
+	struct greth_private *greth;
+	struct greth_regs *regs;
+
+	greth = (struct greth_private *) netdev_priv(dev);
+	regs = (struct greth_regs *) greth->regs;
+
+	if (!is_valid_ether_addr(addr->sa_data))
+		return -EINVAL;
+
+	memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);
+
+	GRETH_REGSAVE(regs->esa_msb, addr->sa_data[0] << 8 | addr->sa_data[1]);
+	GRETH_REGSAVE(regs->esa_lsb,
+		      addr->sa_data[2] << 24 | addr->
+		      sa_data[3] << 16 | addr->sa_data[4] << 8 | addr->sa_data[5]);
+	return 0;
+}
+
+static u32 greth_hash_get_index(__u8 *addr)
+{
+	return (ether_crc(6, addr)) & 0x3F;
+}
+
+static void greth_set_hash_filter(struct net_device *dev)
+{
+	struct dev_mc_list *curr;
+	struct greth_private *greth = (struct greth_private *) netdev_priv(dev);
+	struct greth_regs *regs = (struct greth_regs *) greth->regs;
+	u32 mc_filter[2];
+	unsigned int i, bitnr;
+
+	mc_filter[0] = mc_filter[1] = 0;
+
+	curr = dev->mc_list;
+
+	for (i = 0; i < dev->mc_count; i++, curr = curr->next) {
+
+		if (!curr)
+			break;	/* unexpected end of list */
+
+		bitnr = greth_hash_get_index(curr->dmi_addr);
+		mc_filter[bitnr >> 5] |= 1 << (bitnr & 31);
+	}
+
+	GRETH_REGSAVE(regs->hash_msb, mc_filter[1]);
+	GRETH_REGSAVE(regs->hash_lsb, mc_filter[0]);
+}
+
+static void greth_set_multicast_list(struct net_device *dev)
+{
+	int cfg;
+	struct greth_private *greth = netdev_priv(dev);
+	struct greth_regs *regs = (struct greth_regs *) greth->regs;
+
+	cfg = GRETH_REGLOAD(regs->control);
+	if (dev->flags & IFF_PROMISC)
+		cfg |= GRETH_CTRL_PR;
+	else
+		cfg &= ~GRETH_CTRL_PR;
+
+	if (greth->multicast) {
+		if (dev->flags & IFF_ALLMULTI) {
+			GRETH_REGSAVE(regs->hash_msb, -1);
+			GRETH_REGSAVE(regs->hash_lsb, -1);
+			cfg |= GRETH_CTRL_MCEN;
+			GRETH_REGSAVE(regs->control, cfg);
+			return;
+		}
+
+		if (dev->mc_count == 0) {
+			cfg &= ~GRETH_CTRL_MCEN;
+			GRETH_REGSAVE(regs->control, cfg);
+			return;
+		}
+
+		/* Setup multicast filter */
+		greth_set_hash_filter(dev);
+		cfg |= GRETH_CTRL_MCEN;
+	}
+	GRETH_REGSAVE(regs->control, cfg);
+}
+
+static u32 greth_get_msglevel(struct net_device *dev)
+{
+	struct greth_private *greth = netdev_priv(dev);
+	return greth->msg_enable;
+}
+
+static void greth_set_msglevel(struct net_device *dev, u32 value)
+{
+	struct greth_private *greth = netdev_priv(dev);
+	greth->msg_enable = value;
+}
+static int greth_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
+{
+	struct greth_private *greth = netdev_priv(dev);
+	struct phy_device *phy = greth->phy;
+
+	if (!phy)
+		return -ENODEV;
+
+	return phy_ethtool_gset(phy, cmd);
+}
+
+static int greth_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
+{
+	struct greth_private *greth = netdev_priv(dev);
+	struct phy_device *phy = greth->phy;
+
+	if (!phy)
+		return -ENODEV;
+
+	return phy_ethtool_sset(phy, cmd);
+}
+
+static int greth_get_regs_len(struct net_device *dev)
+{
+	return sizeof(struct greth_regs);
+}
+
+static void greth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
+{
+	struct greth_private *greth = netdev_priv(dev);
+
+	strncpy(info->driver, dev_driver_string(greth->dev), 32);
+	strncpy(info->version, "revision: 1.0", 32);
+	strncpy(info->bus_info, greth->dev->bus->name, 32);
+	strncpy(info->fw_version, "N/A", 32);
+	info->eedump_len = 0;
+	info->regdump_len = sizeof(struct greth_regs);
+}
+
+static void greth_get_regs(struct net_device *dev, struct ethtool_regs *regs, void *p)
+{
+	int i;
+	struct greth_private *greth = netdev_priv(dev);
+	u32 __iomem *greth_regs = (u32 __iomem *) greth->regs;
+	u32 *buff = p;
+
+	for (i = 0; i < sizeof(struct greth_regs) / sizeof(u32); i++)
+		buff[i] = greth_read_bd(&greth_regs[i]);
+}
+
+static u32 greth_get_rx_csum(struct net_device *dev)
+{
+	struct greth_private *greth = netdev_priv(dev);
+	return (greth->flags & GRETH_FLAG_RX_CSUM) != 0;
+}
+
+static int greth_set_rx_csum(struct net_device *dev, u32 data)
+{
+	struct greth_private *greth = netdev_priv(dev);
+
+	spin_lock_bh(&greth->devlock);
+
+	if (data)
+		greth->flags |= GRETH_FLAG_RX_CSUM;
+	else
+		greth->flags &= ~GRETH_FLAG_RX_CSUM;
+
+	spin_unlock_bh(&greth->devlock);
+
+	return 0;
+}
+
+static u32 greth_get_tx_csum(struct net_device *dev)
+{
+	return (dev->features & NETIF_F_IP_CSUM) != 0;
+}
+
+static int greth_set_tx_csum(struct net_device *dev, u32 data)
+{
+	netif_tx_lock_bh(dev);
+	ethtool_op_set_tx_csum(dev, data);
+	netif_tx_unlock_bh(dev);
+	return 0;
+}
+
+static const struct ethtool_ops greth_ethtool_ops = {
+	.get_msglevel		= greth_get_msglevel,
+	.set_msglevel		= greth_set_msglevel,
+	.get_settings		= greth_get_settings,
+	.set_settings		= greth_set_settings,
+	.get_drvinfo		= greth_get_drvinfo,
+	.get_regs_len           = greth_get_regs_len,
+	.get_regs               = greth_get_regs,
+	.get_rx_csum		= greth_get_rx_csum,
+	.set_rx_csum		= greth_set_rx_csum,
+	.get_tx_csum		= greth_get_tx_csum,
+	.set_tx_csum		= greth_set_tx_csum,
+	.get_link		= ethtool_op_get_link,
+};
+
+static struct net_device_ops greth_netdev_ops = {
+	.ndo_open = greth_open,
+	.ndo_stop = greth_close,
+	.ndo_start_xmit = greth_start_xmit,
+	.ndo_set_mac_address = greth_set_mac_add,
+};
+
+static inline int wait_for_mdio(struct greth_private *greth)
+{
+	unsigned long timeout = jiffies + 4*HZ/100;
+	while (GRETH_REGLOAD(greth->regs->mdio) & GRETH_MII_BUSY) {
+		if (time_after(jiffies, timeout))
+			return 0;
+	}
+	return 1;
+}
+
+static int greth_mdio_read(struct mii_bus *bus, int phy, int reg)
+{
+	struct greth_private *greth = bus->priv;
+	int data;
+
+	if (!wait_for_mdio(greth))
+		return -EBUSY;
+
+	GRETH_REGSAVE(greth->regs->mdio, ((phy & 0x1F) << 11) | ((reg & 0x1F) << 6) | 2);
+
+	if (!wait_for_mdio(greth))
+		return -EBUSY;
+
+	if (!(GRETH_REGLOAD(greth->regs->mdio) & GRETH_MII_NVALID)) {
+		data = (GRETH_REGLOAD(greth->regs->mdio) >> 16) & 0xFFFF;
+		return data;
+
+	} else {
+		return -1;
+	}
+}
+
+static int greth_mdio_write(struct mii_bus *bus, int phy, int reg, u16 val)
+{
+	struct greth_private *greth = bus->priv;
+
+	if (!wait_for_mdio(greth))
+		return -EBUSY;
+
+	GRETH_REGSAVE(greth->regs->mdio,
+		      ((val & 0xFFFF) << 16) | ((phy & 0x1F) << 11) | ((reg & 0x1F) << 6) | 1);
+
+	if (!wait_for_mdio(greth))
+		return -EBUSY;
+
+	return 0;
+}
+
+static int greth_mdio_reset(struct mii_bus *bus)
+{
+	return 0;
+}
+
+static void greth_link_change(struct net_device *dev)
+{
+	struct greth_private *greth = netdev_priv(dev);
+	struct phy_device *phydev = greth->phy;
+	unsigned long flags;
+
+	int status_change = 0;
+
+	spin_lock_irqsave(&greth->devlock, flags);
+
+	if (phydev->link) {
+
+		if ((greth->speed != phydev->speed) || (greth->duplex != phydev->duplex)) {
+
+			GRETH_REGANDIN(greth->regs->control,
+				       ~(GRETH_CTRL_FD | GRETH_CTRL_SP | GRETH_CTRL_GB));
+
+			if (phydev->duplex)
+				GRETH_REGORIN(greth->regs->control, GRETH_CTRL_FD);
+
+			if (phydev->speed == SPEED_100) {
+
+				GRETH_REGORIN(greth->regs->control, GRETH_CTRL_SP);
+			}
+
+			else if (phydev->speed == SPEED_1000)
+				GRETH_REGORIN(greth->regs->control, GRETH_CTRL_GB);
+
+			greth->speed = phydev->speed;
+			greth->duplex = phydev->duplex;
+			status_change = 1;
+		}
+	}
+
+	if (phydev->link != greth->link) {
+		if (!phydev->link) {
+			greth->speed = 0;
+			greth->duplex = -1;
+		}
+		greth->link = phydev->link;
+
+		status_change = 1;
+	}
+
+	spin_unlock_irqrestore(&greth->devlock, flags);
+
+	if (status_change) {
+		if (phydev->link)
+			pr_debug("%s: link up (%d/%s)\n",
+				dev->name, phydev->speed,
+				DUPLEX_FULL == phydev->duplex ? "Full" : "Half");
+		else
+			pr_debug("%s: link down\n", dev->name);
+	}
+}
+
+static int greth_mdio_probe(struct net_device *dev)
+{
+	struct greth_private *greth = netdev_priv(dev);
+	struct phy_device *phy = NULL;
+	u32 interface;
+	int i;
+
+	/* Find the first PHY */
+	for (i = 0; i < PHY_MAX_ADDR; i++) {
+		if (greth->mdio->phy_map[i]) {
+			phy = greth->mdio->phy_map[i];
+			break;
+		}
+	}
+	if (!phy) {
+		if (netif_msg_probe(greth))
+			dev_err(&dev->dev, "no PHY found\n");
+		return -ENXIO;
+	}
+
+	if (greth->gbit_mac)
+		interface = PHY_INTERFACE_MODE_GMII;
+	else
+		interface = PHY_INTERFACE_MODE_MII;
+
+	phy = phy_connect(dev, dev_name(&phy->dev), &greth_link_change, 0, interface);
+
+	if (greth->gbit_mac)
+		phy->supported &= PHY_GBIT_FEATURES;
+	else
+		phy->supported &= PHY_BASIC_FEATURES;
+
+	phy->advertising = phy->supported;
+
+	if (IS_ERR(phy)) {
+		if (netif_msg_ifup(greth))
+			dev_err(&dev->dev, "could not attach to PHY\n");
+		return PTR_ERR(phy);
+	}
+
+	greth->link = 0;
+	greth->speed = 0;
+	greth->duplex = -1;
+	greth->phy = phy;
+
+	return 0;
+}
+
+static inline int phy_aneg_done(struct phy_device *phydev)
+{
+	int retval;
+
+	retval = phy_read(phydev, MII_BMSR);
+
+	return (retval < 0) ? retval : (retval & BMSR_ANEGCOMPLETE);
+}
+
+static int greth_mdio_init(struct greth_private *greth)
+{
+	int ret, phy;
+	unsigned long timeout;
+
+	greth->mdio = mdiobus_alloc();
+	if (!greth->mdio) {
+		return -ENOMEM;
+	}
+
+	greth->mdio->name = "greth-mdio";
+	snprintf(greth->mdio->id, MII_BUS_ID_SIZE, "%s-%d", greth->mdio->name, greth->irq);
+	greth->mdio->read = greth_mdio_read;
+	greth->mdio->write = greth_mdio_write;
+	greth->mdio->reset = greth_mdio_reset;
+	greth->mdio->priv = greth;
+
+	greth->mdio->irq = greth->mdio_irqs;
+
+	for (phy = 0; phy < PHY_MAX_ADDR; phy++)
+		greth->mdio->irq[phy] = PHY_POLL;
+
+	ret = mdiobus_register(greth->mdio);
+	if (ret) {
+		goto error;
+	}
+
+	ret = greth_mdio_probe(greth->netdev);
+	if (ret) {
+		if (netif_msg_probe(greth))
+			dev_err(&greth->netdev->dev, "failed to probe MDIO bus\n");
+		goto unreg_mdio;
+	}
+
+	phy_start(greth->phy);
+
+	/* If Ethernet debug link is used make autoneg happen right away */
+	if (greth->edcl && greth_edcl == 1) {
+		phy_start_aneg(greth->phy);
+		timeout = jiffies + 6*HZ;
+		while (!phy_aneg_done(greth->phy) && time_before(jiffies, timeout)) {
+		}
+		genphy_read_status(greth->phy);
+		greth_link_change(greth->netdev);
+	}
+
+	return 0;
+
+unreg_mdio:
+	mdiobus_unregister(greth->mdio);
+error:
+	mdiobus_free(greth->mdio);
+	return ret;
+}
+
+/* Initialize the GRETH MAC */
+static int __devinit greth_of_probe(struct of_device *ofdev, const struct of_device_id *match)
+{
+	struct net_device *dev;
+	struct greth_private *greth;
+	struct greth_regs *regs;
+
+	int i;
+	int err;
+	int tmp;
+	unsigned long timeout;
+
+	dev = alloc_etherdev(sizeof(struct greth_private));
+
+	if (dev == NULL)
+		return -ENOMEM;
+
+	greth = netdev_priv(dev);
+	greth->netdev = dev;
+	greth->dev = &ofdev->dev;
+
+	if (greth_debug > 0)
+		greth->msg_enable = greth_debug;
+	else
+		greth->msg_enable = GRETH_DEF_MSG_ENABLE;
+
+	spin_lock_init(&greth->devlock);
+
+	greth->regs = of_ioremap(&ofdev->resource[0], 0,
+				 resource_size(&ofdev->resource[0]),
+				 "grlib-greth regs");
+
+	if (greth->regs == NULL) {
+		if (netif_msg_probe(greth))
+			dev_err(greth->dev, "ioremap failure.\n");
+		err = -EIO;
+		goto error1;
+	}
+
+	regs = (struct greth_regs *) greth->regs;
+	greth->irq = ofdev->irqs[0];
+
+	dev_set_drvdata(greth->dev, dev);
+	SET_NETDEV_DEV(dev, greth->dev);
+
+	if (netif_msg_probe(greth))
+		dev_dbg(greth->dev, "reseting controller.\n");
+
+	/* Reset the controller. */
+	GRETH_REGSAVE(regs->control, GRETH_RESET);
+
+	/* Wait for MAC to reset itself */
+	timeout = jiffies + HZ/100;
+	while (GRETH_REGLOAD(regs->control) & GRETH_RESET) {
+		if (time_after(jiffies, timeout)) {
+			err = -EIO;
+			if (netif_msg_probe(greth))
+				dev_err(greth->dev, "timeout when waiting for reset.\n");
+			goto error2;
+		}
+	}
+
+	/* Get default PHY address  */
+	greth->phyaddr = (GRETH_REGLOAD(regs->mdio) >> 11) & 0x1F;
+
+	/* Check if we have GBIT capable MAC */
+	tmp = GRETH_REGLOAD(regs->control);
+	greth->gbit_mac = (tmp >> 27) & 1;
+
+	/* Check for multicast capability */
+	greth->multicast = (tmp >> 25) & 1;
+
+	greth->edcl = (tmp >> 31) & 1;
+
+	/* If we have EDCL we disable the EDCL speed-duplex FSM so
+	 * it doesn't interfere with the software */
+	if (greth->edcl != 0)
+		GRETH_REGORIN(regs->control, GRETH_CTRL_DISDUPLEX);
+
+	/* Check if MAC can handle MDIO interrupts */
+	greth->mdio_int_en = (tmp >> 26) & 1;
+
+	err = greth_mdio_init(greth);
+	if (err) {
+		if (netif_msg_probe(greth))
+			dev_err(greth->dev, "failed to register MDIO bus\n");
+		goto error2;
+	}
+
+	/* Allocate TX descriptor ring in coherent memory */
+	greth->tx_bd_base = (struct greth_bd *) dma_alloc_coherent(greth->dev,
+								   1024,
+								   &greth->tx_bd_base_phys,
+								   GFP_KERNEL);
+
+	if (!greth->tx_bd_base) {
+		if (netif_msg_probe(greth))
+			dev_err(&dev->dev, "could not allocate descriptor memory.\n");
+		err = -ENOMEM;
+		goto error3;
+	}
+
+	memset(greth->tx_bd_base, 0, 1024);
+
+	/* Allocate RX descriptor ring in coherent memory */
+	greth->rx_bd_base = (struct greth_bd *) dma_alloc_coherent(greth->dev,
+								   1024,
+								   &greth->rx_bd_base_phys,
+								   GFP_KERNEL);
+
+	if (!greth->rx_bd_base) {
+		if (netif_msg_probe(greth))
+			dev_err(greth->dev, "could not allocate descriptor memory.\n");
+		err = -ENOMEM;
+		goto error4;
+	}
+
+	memset(greth->rx_bd_base, 0, 1024);
+
+	/* Get MAC address from: module param, OF property or ID prom */
+	for (i = 0; i < 6; i++) {
+		if (macaddr[i] != 0)
+			break;
+	}
+	if (i == 6) {
+		const unsigned char *addr;
+		int len;
+		addr = of_get_property(ofdev->node, "local-mac-address", &len);
+		if (addr != NULL && len == 6) {
+			for (i = 0; i < 6; i++)
+				macaddr[i] = (unsigned int) addr[i];
+		} else {
+#ifdef CONFIG_SPARC
+			for (i = 0; i < 6; i++)
+				macaddr[i] = (unsigned int) idprom->id_ethaddr[i];
+#endif
+		}
+	}
+
+	for (i = 0; i < 6; i++)
+		dev->dev_addr[i] = macaddr[i];
+
+	macaddr[5]++;
+
+	if (!is_valid_ether_addr(&dev->dev_addr[0])) {
+		if (netif_msg_probe(greth))
+			dev_err(greth->dev, "no valid ethernet address, aborting.\n");
+		err = -EINVAL;
+		goto error5;
+	}
+
+	GRETH_REGSAVE(regs->esa_msb, dev->dev_addr[0] << 8 | dev->dev_addr[1]);
+	GRETH_REGSAVE(regs->esa_lsb, dev->dev_addr[2] << 24 | dev->dev_addr[3] << 16 |
+		      dev->dev_addr[4] << 8 | dev->dev_addr[5]);
+
+	/* Clear all pending interrupts except PHY irq */
+	GRETH_REGSAVE(regs->status, 0xFF);
+
+	if (greth->gbit_mac) {
+		dev->features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_HIGHDMA;
+		greth_netdev_ops.ndo_start_xmit = greth_start_xmit_gbit;
+		greth->flags = GRETH_FLAG_RX_CSUM;
+	}
+
+	if (greth->multicast) {
+		greth_netdev_ops.ndo_set_multicast_list = greth_set_multicast_list;
+		dev->flags |= IFF_MULTICAST;
+	} else {
+		dev->flags &= ~IFF_MULTICAST;
+	}
+
+	dev->netdev_ops = &greth_netdev_ops;
+	dev->ethtool_ops = &greth_ethtool_ops;
+
+	if (register_netdev(dev)) {
+		if (netif_msg_probe(greth))
+			dev_err(greth->dev, "netdevice registration failed.\n");
+		err = -ENOMEM;
+		goto error5;
+	}
+
+	/* setup NAPI */
+	memset(&greth->napi, 0, sizeof(greth->napi));
+	netif_napi_add(dev, &greth->napi, greth_poll, 64);
+
+	return 0;
+
+error5:
+	dma_free_coherent(greth->dev, 1024, greth->rx_bd_base, greth->rx_bd_base_phys);
+error4:
+	dma_free_coherent(greth->dev, 1024, greth->tx_bd_base, greth->tx_bd_base_phys);
+error3:
+	mdiobus_unregister(greth->mdio);
+error2:
+	of_iounmap(&ofdev->resource[0], greth->regs, resource_size(&ofdev->resource[0]));
+error1:
+	free_netdev(dev);
+	return err;
+}
+
+static int __devexit greth_of_remove(struct of_device *of_dev)
+{
+	struct net_device *ndev = dev_get_drvdata(&of_dev->dev);
+	struct greth_private *greth = netdev_priv(ndev);
+
+	/* Free descriptor areas */
+	dma_free_coherent(&of_dev->dev, 1024, greth->rx_bd_base, greth->rx_bd_base_phys);
+
+	dma_free_coherent(&of_dev->dev, 1024, greth->tx_bd_base, greth->tx_bd_base_phys);
+
+	dev_set_drvdata(&of_dev->dev, NULL);
+
+	if (greth->phy)
+		phy_stop(greth->phy);
+	mdiobus_unregister(greth->mdio);
+
+	unregister_netdev(ndev);
+	free_netdev(ndev);
+
+	of_iounmap(&of_dev->resource[0], greth->regs, resource_size(&of_dev->resource[0]));
+
+	return 0;
+}
+
+static struct of_device_id greth_of_match[] = {
+	{
+	 .name = "GAISLER_ETHMAC",
+	 },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, greth_of_match);
+
+static struct of_platform_driver greth_of_driver = {
+	.name = "grlib-greth",
+	.match_table = greth_of_match,
+	.probe = greth_of_probe,
+	.remove = __devexit_p(greth_of_remove),
+	.driver = {
+		   .owner = THIS_MODULE,
+		   .name = "grlib-greth",
+		   },
+};
+
+static int __init greth_init(void)
+{
+	return of_register_platform_driver(&greth_of_driver);
+}
+
+static void __exit greth_cleanup(void)
+{
+	of_unregister_platform_driver(&greth_of_driver);
+}
+
+module_init(greth_init);
+module_exit(greth_cleanup);
+
+MODULE_AUTHOR("Aeroflex Gaisler AB.");
+MODULE_DESCRIPTION("Aeroflex Gaisler Ethernet MAC driver");
+MODULE_LICENSE("GPL");