text: // SPDX-License-Identifier: GPL-2.0-or-later
  /*
   * Aeroflex Gaisler GRETH 10/100/1G Ethernet MAC.
   *
   * 2005-2010 (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:
   * https://www.gaisler.com/products/grlib/grip.pdf
   *
   * The Gigabit version supports scatter/gather DMA, any alignment of
   * buffers and checksum offloading.
   *
   * Contributors: Kristoffer Glembo
   *               Daniel Hellstrom
   *               Marko Isomaki
   */
  
  #include <linux/dma-mapping.h>
  #include <linux/module.h>
  #include <linux/uaccess.h>
  #include <linux/interrupt.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_net.h>
  #include <linux/of_platform.h>
  #include <linux/slab.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 netdev_tx_t greth_start_xmit(struct sk_buff *skb,
  	   struct net_device *dev);
  static netdev_tx_t 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,
  			       skb_frag_address(&skb_shinfo(skb)->frags[i]),
  			       skb_frag_size(&skb_shinfo(skb)->frags[i]), true);
  	}
  }
  
  static inline void greth_enable_tx(struct greth_private *greth)
  {
  	wmb();
  	GRETH_REGORIN(greth->regs->control, GRETH_TXEN);
  }
  
  static inline void greth_enable_tx_and_irq(struct greth_private *greth)
  {
  	wmb(); /* BDs must been written to memory before enabling TX */
  	GRETH_REGORIN(greth->regs->control, GRETH_TXEN | GRETH_TXI);
  }
  
  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),
  					       skb_frag_size(frag),
  					       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);
  
  	GRETH_REGSAVE(greth->regs->status, 0xFF);
  
  	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_irqs(greth);
  	greth_disable_tx(greth);
  	greth_disable_rx(greth);
  
  	netif_stop_queue(dev);
  
  	free_irq(greth->irq, (void *) dev);
  
  	greth_clean_rings(greth);
  
  	return 0;
  }
  
  static netdev_tx_t
  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, ctrl;
  	unsigned long flags;
  
  	/* Clean TX Ring */
  	greth_clean_tx(greth->netdev);
  
  	if (unlikely(greth->tx_free <= 0)) {
  		spin_lock_irqsave(&greth->devlock, flags);/*save from poll/irq*/
  		ctrl = GRETH_REGLOAD(greth->regs->control);
  		/* Enable TX IRQ only if not already in poll() routine */
  		if (ctrl & GRETH_RXI)
  			GRETH_REGSAVE(greth->regs->control, ctrl | GRETH_TXI);
  		netif_stop_queue(dev);
  		spin_unlock_irqrestore(&greth->devlock, flags);
  		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;
  	}
  
  	bdp = greth->tx_bd_base + greth->tx_next;
  	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 | GRETH_BD_IE | (skb->len & GRETH_BD_LEN);
  	greth->tx_bufs_length[greth->tx_next] = 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--;
  
  	/* Write descriptor control word and enable transmission */
  	greth_write_bd(&bdp->stat, status);
  	spin_lock_irqsave(&greth->devlock, flags); /*save from poll/irq*/
  	greth_enable_tx(greth);
  	spin_unlock_irqrestore(&greth->devlock, flags);
  
  out:
  	dev_kfree_skb(skb);
  	return err;
  }
  
  static inline u16 greth_num_free_bds(u16 tx_last, u16 tx_next)
  {
  	if (tx_next < tx_last)
  		return (tx_last - tx_next) - 1;
  	else
  		return GRETH_TXBD_NUM - (tx_next - tx_last) - 1;
  }
  
  static netdev_tx_t
  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, dma_addr;
  	int curr_tx, nr_frags, i, err = NETDEV_TX_OK;
  	unsigned long flags;
  	u16 tx_last;
  
  	nr_frags = skb_shinfo(skb)->nr_frags;
  	tx_last = greth->tx_last;
  	rmb(); /* tx_last is updated by the poll task */
  
  	if (greth_num_free_bds(tx_last, greth->tx_next) < 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;
  	else
  		status = GRETH_BD_IE;
  
  	if (skb->ip_summed == CHECKSUM_PARTIAL)
  		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_BD_EN;
  		if (skb->ip_summed == CHECKSUM_PARTIAL)
  			status |= GRETH_TXBD_CSALL;
  		status |= skb_frag_size(frag) & 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;
  		else
  			status |= GRETH_BD_IE; /* enable IRQ on last fragment */
  
  		greth_write_bd(&bdp->stat, status);
  
  		dma_addr = skb_frag_dma_map(greth->dev, frag, 0, skb_frag_size(frag),
  					    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 descriptor chain by enabling the first descriptor */
  	bdp = greth->tx_bd_base + greth->tx_next;
  	greth_write_bd(&bdp->stat,
  		       greth_read_bd(&bdp->stat) | GRETH_BD_EN);
  
  	spin_lock_irqsave(&greth->devlock, flags); /*save from poll/irq*/
  	greth->tx_next = curr_tx;
  	greth_enable_tx_and_irq(greth);
  	spin_unlock_irqrestore(&greth->devlock, flags);
  
  	return NETDEV_TX_OK;
  
  frag_map_error:
  	/* Unmap SKB mappings that succeeded and disable descriptor */
  	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);
  		greth_write_bd(&bdp->stat, 0);
  	}
  map_error:
  	if (net_ratelimit())
  		dev_warn(greth->dev, "Could not create TX DMA mapping\n");
  	dev_kfree_skb(skb);
  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, ctrl;
  	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);
  
  	/* Must see if interrupts are enabled also, INT_TX|INT_RX flags may be
  	 * set regardless of whether IRQ is enabled or not. Especially
  	 * important when shared IRQ.
  	 */
  	ctrl = GRETH_REGLOAD(greth->regs->control);
  
  	/* Handle rx and tx interrupts through poll */
  	if (((status & (GRETH_INT_RE | GRETH_INT_RX)) && (ctrl & GRETH_RXI)) ||
  	    ((status & (GRETH_INT_TE | GRETH_INT_TX)) && (ctrl & GRETH_TXI))) {
  		retval = IRQ_HANDLED;
  
  		/* Disable interrupts and schedule poll() */
  		greth_disable_irqs(greth);
  		napi_schedule(&greth->napi);
  	}
  
  	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;
  		GRETH_REGSAVE(greth->regs->status, GRETH_INT_TE | GRETH_INT_TX);
  		mb();
  		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++;
  		dev->stats.tx_bytes += greth->tx_bufs_length[greth->tx_last];
  		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 = NULL;
  	u32 stat;
  	int nr_frags, i;
  	u16 tx_last;
  
  	greth = netdev_priv(dev);
  	tx_last = greth->tx_last;
  
  	while (tx_last != greth->tx_next) {
  
  		skb = greth->tx_skbuff[tx_last];
  
  		nr_frags = skb_shinfo(skb)->nr_frags;
  
  		/* We only clean fully completed SKBs */
  		bdp_last_frag = greth->tx_bd_base + SKIP_TX(tx_last, nr_frags);
  
  		GRETH_REGSAVE(greth->regs->status, GRETH_INT_TE | GRETH_INT_TX);
  		mb();
  		stat = greth_read_bd(&bdp_last_frag->stat);
  
  		if (stat & GRETH_BD_EN)
  			break;
  
  		greth->tx_skbuff[tx_last] = NULL;
  
  		greth_update_tx_stats(dev, stat);
  		dev->stats.tx_bytes += skb->len;
  
  		bdp = greth->tx_bd_base + tx_last;
  
  		tx_last = NEXT_TX(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 + tx_last;
  
  			dma_unmap_page(greth->dev,
  				       greth_read_bd(&bdp->addr),
  				       skb_frag_size(frag),
  				       DMA_TO_DEVICE);
  
  			tx_last = NEXT_TX(tx_last);
  		}
  		dev_kfree_skb(skb);
  	}
  	if (skb) { /* skb is set only if the above while loop was entered */
  		wmb();
  		greth->tx_last = tx_last;
  
  		if (netif_queue_stopped(dev) &&
  		    (greth_num_free_bds(tx_last, greth->tx_next) >
  		    (MAX_SKB_FRAGS+1)))
  			netif_wake_queue(dev);
  	}
  }
  
  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;
  	unsigned long flags;
  
  	greth = netdev_priv(dev);
  
  	for (count = 0; count < limit; ++count) {
  
  		bdp = greth->rx_bd_base + greth->rx_cur;
  		GRETH_REGSAVE(greth->regs->status, GRETH_INT_RE | GRETH_INT_RX);
  		mb();
  		status = greth_read_bd(&bdp->stat);
  
  		if (unlikely(status & GRETH_BD_EN)) {
  			break;
  		}
  
  		dma_addr = greth_read_bd(&bdp->addr);
  		bad = 0;
  
  		/* 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);
  
  				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);
  
  				skb_put_data(skb, phys_to_virt(dma_addr),
  					     pkt_len);
  
  				skb->protocol = eth_type_trans(skb, dev);
  				dev->stats.rx_bytes += pkt_len;
  				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);
  
  		spin_lock_irqsave(&greth->devlock, flags); /* save from XMIT */
  		greth_enable_rx(greth);
  		spin_unlock_irqrestore(&greth->devlock, flags);
  
  		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;
  	unsigned long flags;
  
  	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];
  		GRETH_REGSAVE(greth->regs->status, GRETH_INT_RE | GRETH_INT_RX);
  		mb();
  		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, not needed if the
  		 * current skb can be reused */
  		if (!bad && (newskb=netdev_alloc_skb(dev, MAX_FRAME_SIZE + NET_IP_ALIGN))) {
  			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 (dev->features & NETIF_F_RXCSUM && hw_checksummed(status))
  					skb->ip_summed = CHECKSUM_UNNECESSARY;
  				else
  					skb_checksum_none_assert(skb);
  
  				skb->protocol = eth_type_trans(skb, dev);
  				dev->stats.rx_packets++;
  				dev->stats.rx_bytes += pkt_len;
  				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);
  				/* reusing current skb, so it is a drop */
  				dev->stats.rx_dropped++;
  			}
  		} else if (bad) {
  			/* Bad Frame transfer, the skb is reused */
  			dev->stats.rx_dropped++;
  		} else {
  			/* Failed Allocating a new skb. This is rather stupid
  			 * but the current "filled" skb is reused, as if
  			 * transfer failure. One could argue that RX descriptor
  			 * table handling should be divided into cleaning and
  			 * filling as the TX part of the driver
  			 */
  			if (net_ratelimit())
  				dev_warn(greth->dev, "Could not allocate SKB, dropping packet\n");
  			/* reusing current skb, so it is a drop */
  			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);
  		spin_lock_irqsave(&greth->devlock, flags);
  		greth_enable_rx(greth);
  		spin_unlock_irqrestore(&greth->devlock, flags);
  		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;
  	unsigned long flags;
  	u32 mask, ctrl;
  	greth = container_of(napi, struct greth_private, napi);
  
  restart_txrx_poll:
  	if (greth->gbit_mac) {
  		greth_clean_tx_gbit(greth->netdev);
  		work_done += greth_rx_gbit(greth->netdev, budget - work_done);
  	} else {
  		if (netif_queue_stopped(greth->netdev))
  			greth_clean_tx(greth->netdev);
  		work_done += greth_rx(greth->netdev, budget - work_done);
  	}
  
  	if (work_done < budget) {
  
  		spin_lock_irqsave(&greth->devlock, flags);
  
  		ctrl = GRETH_REGLOAD(greth->regs->control);
  		if ((greth->gbit_mac && (greth->tx_last != greth->tx_next)) ||
  		    (!greth->gbit_mac && netif_queue_stopped(greth->netdev))) {
  			GRETH_REGSAVE(greth->regs->control,
  					ctrl | GRETH_TXI | GRETH_RXI);
  			mask = GRETH_INT_RX | GRETH_INT_RE |
  			       GRETH_INT_TX | GRETH_INT_TE;
  		} else {
  			GRETH_REGSAVE(greth->regs->control, ctrl | GRETH_RXI);
  			mask = GRETH_INT_RX | GRETH_INT_RE;
  		}
  
  		if (GRETH_REGLOAD(greth->regs->status) & mask) {
  			GRETH_REGSAVE(greth->regs->control, ctrl);
  			spin_unlock_irqrestore(&greth->devlock, flags);
  			goto restart_txrx_poll;
  		} else {
  			napi_complete_done(napi, work_done);
  			spin_unlock_irqrestore(&greth->devlock, flags);
  		}
  	}
  
  	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 = netdev_priv(dev);
  	regs = greth->regs;
  
  	if (!is_valid_ether_addr(addr->sa_data))
  		return -EADDRNOTAVAIL;
  
  	eth_hw_addr_set(dev, addr->sa_data);
  	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]);
  
  	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 netdev_hw_addr *ha;
  	struct greth_private *greth = netdev_priv(dev);
  	struct greth_regs *regs = greth->regs;
  	u32 mc_filter[2];
  	unsigned int bitnr;
  
  	mc_filter[0] = mc_filter[1] = 0;
  
  	netdev_for_each_mc_addr(ha, dev) {
  		bitnr = greth_hash_get_index(ha->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 = 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 (netdev_mc_empty(dev)) {
  			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_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);
  
  	strlcpy(info->driver, dev_driver_string(greth->dev),
  		sizeof(info->driver));
  	strlcpy(info->bus_info, greth->dev->bus->name, sizeof(info->bus_info));
  }
  
  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 const struct ethtool_ops greth_ethtool_ops = {
  	.get_msglevel		= greth_get_msglevel,
  	.set_msglevel		= greth_set_msglevel,
  	.get_drvinfo		= greth_get_drvinfo,
  	.get_regs_len           = greth_get_regs_len,
  	.get_regs               = greth_get_regs,
  	.get_link		= ethtool_op_get_link,
  	.get_link_ksettings	= phy_ethtool_get_link_ksettings,
  	.set_link_ksettings	= phy_ethtool_set_link_ksettings,
  };
  
  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,
  	.ndo_validate_addr	= eth_validate_addr,
  };
  
  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 void greth_link_change(struct net_device *dev)
  {
  	struct greth_private *greth = netdev_priv(dev);
  	struct phy_device *phydev = dev->phydev;
  	unsigned long flags;
  	int status_change = 0;
  	u32 ctrl;
  
  	spin_lock_irqsave(&greth->devlock, flags);
  
  	if (phydev->link) {
  
  		if ((greth->speed != phydev->speed) || (greth->duplex != phydev->duplex)) {
  			ctrl = GRETH_REGLOAD(greth->regs->control) &
  			       ~(GRETH_CTRL_FD | GRETH_CTRL_SP | GRETH_CTRL_GB);
  
  			if (phydev->duplex)
  				ctrl |= GRETH_CTRL_FD;
  
  			if (phydev->speed == SPEED_100)
  				ctrl |= GRETH_CTRL_SP;
  			else if (phydev->speed == SPEED_1000)
  				ctrl |= GRETH_CTRL_GB;
  
  			GRETH_REGSAVE(greth->regs->control, ctrl);
  			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;
  	int ret;
  
  	/* Find the first PHY */
  	phy = phy_find_first(greth->mdio);
  
  	if (!phy) {
  		if (netif_msg_probe(greth))
  			dev_err(&dev->dev, "no PHY found\n");
  		return -ENXIO;
  	}
  
  	ret = phy_connect_direct(dev, phy, &greth_link_change,
  				 greth->gbit_mac ? PHY_INTERFACE_MODE_GMII : PHY_INTERFACE_MODE_MII);
  	if (ret) {
  		if (netif_msg_ifup(greth))
  			dev_err(&dev->dev, "could not attach to PHY\n");
  		return ret;
  	}
  
  	if (greth->gbit_mac)
  		phy_set_max_speed(phy, SPEED_1000);
  	else
  		phy_set_max_speed(phy, SPEED_100);
  
  	linkmode_copy(phy->advertising, phy->supported);
  
  	greth->link = 0;
  	greth->speed = 0;
  	greth->duplex = -1;
  
  	return 0;
  }
  
  static int greth_mdio_init(struct greth_private *greth)
  {
  	int ret;
  	unsigned long timeout;
  	struct net_device *ndev = greth->netdev;
  
  	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->priv = greth;
  
  	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(ndev->phydev);
  
  	/* If Ethernet debug link is used make autoneg happen right away */
  	if (greth->edcl && greth_edcl == 1) {
  		phy_start_aneg(ndev->phydev);
  		timeout = jiffies + 6*HZ;
  		while (!phy_aneg_done(ndev->phydev) &&
  		       time_before(jiffies, timeout)) {
  		}
  		phy_read_status(ndev->phydev);
  		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 greth_of_probe(struct platform_device *ofdev)
  {
  	struct net_device *dev;
  	struct greth_private *greth;
  	struct greth_regs *regs;
  
  	int i;
  	int err;
  	int tmp;
  	u8 addr[ETH_ALEN];
  	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 = greth->regs;
  	greth->irq = ofdev->archdata.irqs[0];
  
  	dev_set_drvdata(greth->dev, dev);
  	SET_NETDEV_DEV(dev, greth->dev);
  
  	if (netif_msg_probe(greth))
  		dev_dbg(greth->dev, "resetting 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 = dma_alloc_coherent(greth->dev, 1024,
  					       &greth->tx_bd_base_phys,
  					       GFP_KERNEL);
  	if (!greth->tx_bd_base) {
  		err = -ENOMEM;
  		goto error3;
  	}
  
  	/* Allocate RX descriptor ring in coherent memory */
  	greth->rx_bd_base = dma_alloc_coherent(greth->dev, 1024,
  					       &greth->rx_bd_base_phys,
  					       GFP_KERNEL);
  	if (!greth->rx_bd_base) {
  		err = -ENOMEM;
  		goto error4;
  	}
  
  	/* 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) {
  		err = of_get_mac_address(ofdev->dev.of_node, addr);
  		if (!err) {
  			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++)
  		addr[i] = macaddr[i];
  	eth_hw_addr_set(dev, addr);
  
  	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->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM |
  			NETIF_F_RXCSUM;
  		dev->features = dev->hw_features | NETIF_F_HIGHDMA;
  		greth_netdev_ops.ndo_start_xmit = greth_start_xmit_gbit;
  	}
  
  	if (greth->multicast) {
  		greth_netdev_ops.ndo_set_rx_mode = 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;
  
  	err = register_netdev(dev);
  	if (err) {
  		if (netif_msg_probe(greth))
  			dev_err(greth->dev, "netdevice registration failed.\n");
  		goto error5;
  	}
  
  	/* setup 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 greth_of_remove(struct platform_device *of_dev)
  {
  	struct net_device *ndev = platform_get_drvdata(of_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);
  
  	if (ndev->phydev)
  		phy_stop(ndev->phydev);
  	mdiobus_unregister(greth->mdio);
  
  	unregister_netdev(ndev);
  
  	of_iounmap(&of_dev->resource[0], greth->regs, resource_size(&of_dev->resource[0]));
  
  	free_netdev(ndev);
  
  	return 0;
  }
  
  static const struct of_device_id greth_of_match[] = {
  	{
  	 .name = "GAISLER_ETHMAC",
  	 },
  	{
  	 .name = "01_01d",
  	 },
  	{},
  };
  
  MODULE_DEVICE_TABLE(of, greth_of_match);
  
  static struct platform_driver greth_of_driver = {
  	.driver = {
  		.name = "grlib-greth",
  		.of_match_table = greth_of_match,
  	},
  	.probe = greth_of_probe,
  	.remove = greth_of_remove,
  };
  
  module_platform_driver(greth_of_driver);
  
  MODULE_AUTHOR("Aeroflex Gaisler AB.");
  MODULE_DESCRIPTION("Aeroflex Gaisler Ethernet MAC driver");
  MODULE_LICENSE("GPL");
  