[PATCH] Atmel MACB ethernet driver

Driver for the Atmel MACB on-chip ethernet module.

Tested on AVR32/AT32AP7000/ATSTK1000. I've heard rumours that it works
with AT91SAM9260 as well, and it may be possible to share some code with
the at91_ether driver for AT91RM9200.

Hardware documentation can be found in the AT32AP7000 data sheet,
which can be downloaded from

http://www.atmel.com/dyn/products/datasheets.asp?family_id=682

Changes since previous version:
  * Probe for PHY ID instead of depending on it being provided through
    platform_data.
  * Grab initial ethernet address from the MACB registers instead
    of depending on platform_data.
  * Set MII/RMII mode correctly.

These changes are mostly about making the driver more compatible with
the at91 infrastructure.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 1210 insertions, 0 deletions

diff --git a/drivers/net/macb.c b/drivers/net/macb.c
new file mode 100644
index 000000000000..bd0ce98c939c
--- /dev/null
+++ b/drivers/net/macb.c
@@ -0,0 +1,1210 @@
+/*
+ * Atmel MACB Ethernet Controller driver
+ *
+ * Copyright (C) 2004-2006 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/mii.h>
+#include <linux/mutex.h>
+#include <linux/dma-mapping.h>
+#include <linux/ethtool.h>
+#include <linux/platform_device.h>
+
+#include <asm/arch/board.h>
+
+#include "macb.h"
+
+#define to_net_dev(class) container_of(class, struct net_device, class_dev)
+
+#define RX_BUFFER_SIZE		128
+#define RX_RING_SIZE		512
+#define RX_RING_BYTES		(sizeof(struct dma_desc) * RX_RING_SIZE)
+
+/* Make the IP header word-aligned (the ethernet header is 14 bytes) */
+#define RX_OFFSET		2
+
+#define TX_RING_SIZE		128
+#define DEF_TX_RING_PENDING	(TX_RING_SIZE - 1)
+#define TX_RING_BYTES		(sizeof(struct dma_desc) * TX_RING_SIZE)
+
+#define TX_RING_GAP(bp)						\
+	(TX_RING_SIZE - (bp)->tx_pending)
+#define TX_BUFFS_AVAIL(bp)					\
+	(((bp)->tx_tail <= (bp)->tx_head) ?			\
+	 (bp)->tx_tail + (bp)->tx_pending - (bp)->tx_head :	\
+	 (bp)->tx_tail - (bp)->tx_head - TX_RING_GAP(bp))
+#define NEXT_TX(n)		(((n) + 1) & (TX_RING_SIZE - 1))
+
+#define NEXT_RX(n)		(((n) + 1) & (RX_RING_SIZE - 1))
+
+/* minimum number of free TX descriptors before waking up TX process */
+#define MACB_TX_WAKEUP_THRESH	(TX_RING_SIZE / 4)
+
+#define MACB_RX_INT_FLAGS	(MACB_BIT(RCOMP) | MACB_BIT(RXUBR)	\
+				 | MACB_BIT(ISR_ROVR))
+
+static void __macb_set_hwaddr(struct macb *bp)
+{
+	u32 bottom;
+	u16 top;
+
+	bottom = cpu_to_le32(*((u32 *)bp->dev->dev_addr));
+	macb_writel(bp, SA1B, bottom);
+	top = cpu_to_le16(*((u16 *)(bp->dev->dev_addr + 4)));
+	macb_writel(bp, SA1T, top);
+}
+
+static void __init macb_get_hwaddr(struct macb *bp)
+{
+	u32 bottom;
+	u16 top;
+	u8 addr[6];
+
+	bottom = macb_readl(bp, SA1B);
+	top = macb_readl(bp, SA1T);
+
+	addr[0] = bottom & 0xff;
+	addr[1] = (bottom >> 8) & 0xff;
+	addr[2] = (bottom >> 16) & 0xff;
+	addr[3] = (bottom >> 24) & 0xff;
+	addr[4] = top & 0xff;
+	addr[5] = (top >> 8) & 0xff;
+
+	if (is_valid_ether_addr(addr))
+		memcpy(bp->dev->dev_addr, addr, sizeof(addr));
+}
+
+static void macb_enable_mdio(struct macb *bp)
+{
+	unsigned long flags;
+	u32 reg;
+
+	spin_lock_irqsave(&bp->lock, flags);
+	reg = macb_readl(bp, NCR);
+	reg |= MACB_BIT(MPE);
+	macb_writel(bp, NCR, reg);
+	macb_writel(bp, IER, MACB_BIT(MFD));
+	spin_unlock_irqrestore(&bp->lock, flags);
+}
+
+static void macb_disable_mdio(struct macb *bp)
+{
+	unsigned long flags;
+	u32 reg;
+
+	spin_lock_irqsave(&bp->lock, flags);
+	reg = macb_readl(bp, NCR);
+	reg &= ~MACB_BIT(MPE);
+	macb_writel(bp, NCR, reg);
+	macb_writel(bp, IDR, MACB_BIT(MFD));
+	spin_unlock_irqrestore(&bp->lock, flags);
+}
+
+static int macb_mdio_read(struct net_device *dev, int phy_id, int location)
+{
+	struct macb *bp = netdev_priv(dev);
+	int value;
+
+	mutex_lock(&bp->mdio_mutex);
+
+	macb_enable_mdio(bp);
+	macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF)
+			      | MACB_BF(RW, MACB_MAN_READ)
+			      | MACB_BF(PHYA, phy_id)
+			      | MACB_BF(REGA, location)
+			      | MACB_BF(CODE, MACB_MAN_CODE)));
+
+	wait_for_completion(&bp->mdio_complete);
+
+	value = MACB_BFEXT(DATA, macb_readl(bp, MAN));
+	macb_disable_mdio(bp);
+	mutex_unlock(&bp->mdio_mutex);
+
+	return value;
+}
+
+static void macb_mdio_write(struct net_device *dev, int phy_id,
+			    int location, int val)
+{
+	struct macb *bp = netdev_priv(dev);
+
+	dev_dbg(&bp->pdev->dev, "mdio_write %02x:%02x <- %04x\n",
+		phy_id, location, val);
+
+	mutex_lock(&bp->mdio_mutex);
+	macb_enable_mdio(bp);
+
+	macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF)
+			      | MACB_BF(RW, MACB_MAN_WRITE)
+			      | MACB_BF(PHYA, phy_id)
+			      | MACB_BF(REGA, location)
+			      | MACB_BF(CODE, MACB_MAN_CODE)
+			      | MACB_BF(DATA, val)));
+
+	wait_for_completion(&bp->mdio_complete);
+
+	macb_disable_mdio(bp);
+	mutex_unlock(&bp->mdio_mutex);
+}
+
+static int macb_phy_probe(struct macb *bp)
+{
+	int phy_address;
+	u16 phyid1, phyid2;
+
+	for (phy_address = 0; phy_address < 32; phy_address++) {
+		phyid1 = macb_mdio_read(bp->dev, phy_address, MII_PHYSID1);
+		phyid2 = macb_mdio_read(bp->dev, phy_address, MII_PHYSID2);
+
+		if (phyid1 != 0xffff && phyid1 != 0x0000
+		    && phyid2 != 0xffff && phyid2 != 0x0000)
+			break;
+	}
+
+	if (phy_address == 32)
+		return -ENODEV;
+
+	dev_info(&bp->pdev->dev,
+		 "detected PHY at address %d (ID %04x:%04x)\n",
+		 phy_address, phyid1, phyid2);
+
+	bp->mii.phy_id = phy_address;
+	return 0;
+}
+
+static void macb_set_media(struct macb *bp, int media)
+{
+	u32 reg;
+
+	spin_lock_irq(&bp->lock);
+	reg = macb_readl(bp, NCFGR);
+	reg &= ~(MACB_BIT(SPD) | MACB_BIT(FD));
+	if (media & (ADVERTISE_100HALF | ADVERTISE_100FULL))
+		reg |= MACB_BIT(SPD);
+	if (media & ADVERTISE_FULL)
+		reg |= MACB_BIT(FD);
+	macb_writel(bp, NCFGR, reg);
+	spin_unlock_irq(&bp->lock);
+}
+
+static void macb_check_media(struct macb *bp, int ok_to_print, int init_media)
+{
+	struct mii_if_info *mii = &bp->mii;
+	unsigned int old_carrier, new_carrier;
+	int advertise, lpa, media, duplex;
+
+	/* if forced media, go no further */
+	if (mii->force_media)
+		return;
+
+	/* check current and old link status */
+	old_carrier = netif_carrier_ok(mii->dev) ? 1 : 0;
+	new_carrier = (unsigned int) mii_link_ok(mii);
+
+	/* if carrier state did not change, assume nothing else did */
+	if (!init_media && old_carrier == new_carrier)
+		return;
+
+	/* no carrier, nothing much to do */
+	if (!new_carrier) {
+		netif_carrier_off(mii->dev);
+		printk(KERN_INFO "%s: link down\n", mii->dev->name);
+		return;
+	}
+
+	/*
+	 * we have carrier, see who's on the other end
+	 */
+	netif_carrier_on(mii->dev);
+
+	/* get MII advertise and LPA values */
+	if (!init_media && mii->advertising) {
+		advertise = mii->advertising;
+	} else {
+		advertise = mii->mdio_read(mii->dev, mii->phy_id, MII_ADVERTISE);
+		mii->advertising = advertise;
+	}
+	lpa = mii->mdio_read(mii->dev, mii->phy_id, MII_LPA);
+
+	/* figure out media and duplex from advertise and LPA values */
+	media = mii_nway_result(lpa & advertise);
+	duplex = (media & ADVERTISE_FULL) ? 1 : 0;
+
+	if (ok_to_print)
+		printk(KERN_INFO "%s: link up, %sMbps, %s-duplex, lpa 0x%04X\n",
+		       mii->dev->name,
+		       media & (ADVERTISE_100FULL | ADVERTISE_100HALF) ? "100" : "10",
+		       duplex ? "full" : "half", lpa);
+
+	mii->full_duplex = duplex;
+
+	/* Let the MAC know about the new link state */
+	macb_set_media(bp, media);
+}
+
+static void macb_update_stats(struct macb *bp)
+{
+	u32 __iomem *reg = bp->regs + MACB_PFR;
+	u32 *p = &bp->hw_stats.rx_pause_frames;
+	u32 *end = &bp->hw_stats.tx_pause_frames + 1;
+
+	WARN_ON((unsigned long)(end - p - 1) != (MACB_TPF - MACB_PFR) / 4);
+
+	for(; p < end; p++, reg++)
+		*p += readl(reg);
+}
+
+static void macb_periodic_task(void *arg)
+{
+	struct macb *bp = arg;
+
+	macb_update_stats(bp);
+	macb_check_media(bp, 1, 0);
+
+	schedule_delayed_work(&bp->periodic_task, HZ);
+}
+
+static void macb_tx(struct macb *bp)
+{
+	unsigned int tail;
+	unsigned int head;
+	u32 status;
+
+	status = macb_readl(bp, TSR);
+	macb_writel(bp, TSR, status);
+
+	dev_dbg(&bp->pdev->dev, "macb_tx status = %02lx\n",
+		(unsigned long)status);
+
+	if (status & MACB_BIT(UND)) {
+		printk(KERN_ERR "%s: TX underrun, resetting buffers\n",
+		       bp->dev->name);
+		bp->tx_head = bp->tx_tail = 0;
+	}
+
+	if (!(status & MACB_BIT(COMP)))
+		/*
+		 * This may happen when a buffer becomes complete
+		 * between reading the ISR and scanning the
+		 * descriptors.  Nothing to worry about.
+		 */
+		return;
+
+	head = bp->tx_head;
+	for (tail = bp->tx_tail; tail != head; tail = NEXT_TX(tail)) {
+		struct ring_info *rp = &bp->tx_skb[tail];
+		struct sk_buff *skb = rp->skb;
+		u32 bufstat;
+
+		BUG_ON(skb == NULL);
+
+		rmb();
+		bufstat = bp->tx_ring[tail].ctrl;
+
+		if (!(bufstat & MACB_BIT(TX_USED)))
+			break;
+
+		dev_dbg(&bp->pdev->dev, "skb %u (data %p) TX complete\n",
+			tail, skb->data);
+		dma_unmap_single(&bp->pdev->dev, rp->mapping, skb->len,
+				 DMA_TO_DEVICE);
+		bp->stats.tx_packets++;
+		bp->stats.tx_bytes += skb->len;
+		rp->skb = NULL;
+		dev_kfree_skb_irq(skb);
+	}
+
+	bp->tx_tail = tail;
+	if (netif_queue_stopped(bp->dev) &&
+	    TX_BUFFS_AVAIL(bp) > MACB_TX_WAKEUP_THRESH)
+		netif_wake_queue(bp->dev);
+}
+
+static int macb_rx_frame(struct macb *bp, unsigned int first_frag,
+			 unsigned int last_frag)
+{
+	unsigned int len;
+	unsigned int frag;
+	unsigned int offset = 0;
+	struct sk_buff *skb;
+
+	len = MACB_BFEXT(RX_FRMLEN, bp->rx_ring[last_frag].ctrl);
+
+	dev_dbg(&bp->pdev->dev, "macb_rx_frame frags %u - %u (len %u)\n",
+		first_frag, last_frag, len);
+
+	skb = dev_alloc_skb(len + RX_OFFSET);
+	if (!skb) {
+		bp->stats.rx_dropped++;
+		for (frag = first_frag; ; frag = NEXT_RX(frag)) {
+			bp->rx_ring[frag].addr &= ~MACB_BIT(RX_USED);
+			if (frag == last_frag)
+				break;
+		}
+		wmb();
+		return 1;
+	}
+
+	skb_reserve(skb, RX_OFFSET);
+	skb->dev = bp->dev;
+	skb->ip_summed = CHECKSUM_NONE;
+	skb_put(skb, len);
+
+	for (frag = first_frag; ; frag = NEXT_RX(frag)) {
+		unsigned int frag_len = RX_BUFFER_SIZE;
+
+		if (offset + frag_len > len) {
+			BUG_ON(frag != last_frag);
+			frag_len = len - offset;
+		}
+		memcpy(skb->data + offset,
+		       bp->rx_buffers + (RX_BUFFER_SIZE * frag),
+		       frag_len);
+		offset += RX_BUFFER_SIZE;
+		bp->rx_ring[frag].addr &= ~MACB_BIT(RX_USED);
+		wmb();
+
+		if (frag == last_frag)
+			break;
+	}
+
+	skb->protocol = eth_type_trans(skb, bp->dev);
+
+	bp->stats.rx_packets++;
+	bp->stats.rx_bytes += len;
+	bp->dev->last_rx = jiffies;
+	dev_dbg(&bp->pdev->dev, "received skb of length %u, csum: %08x\n",
+		skb->len, skb->csum);
+	netif_receive_skb(skb);
+
+	return 0;
+}
+
+/* Mark DMA descriptors from begin up to and not including end as unused */
+static void discard_partial_frame(struct macb *bp, unsigned int begin,
+				  unsigned int end)
+{
+	unsigned int frag;
+
+	for (frag = begin; frag != end; frag = NEXT_RX(frag))
+		bp->rx_ring[frag].addr &= ~MACB_BIT(RX_USED);
+	wmb();
+
+	/*
+	 * When this happens, the hardware stats registers for
+	 * whatever caused this is updated, so we don't have to record
+	 * anything.
+	 */
+}
+
+static int macb_rx(struct macb *bp, int budget)
+{
+	int received = 0;
+	unsigned int tail = bp->rx_tail;
+	int first_frag = -1;
+
+	for (; budget > 0; tail = NEXT_RX(tail)) {
+		u32 addr, ctrl;
+
+		rmb();
+		addr = bp->rx_ring[tail].addr;
+		ctrl = bp->rx_ring[tail].ctrl;
+
+		if (!(addr & MACB_BIT(RX_USED)))
+			break;
+
+		if (ctrl & MACB_BIT(RX_SOF)) {
+			if (first_frag != -1)
+				discard_partial_frame(bp, first_frag, tail);
+			first_frag = tail;
+		}
+
+		if (ctrl & MACB_BIT(RX_EOF)) {
+			int dropped;
+			BUG_ON(first_frag == -1);
+
+			dropped = macb_rx_frame(bp, first_frag, tail);
+			first_frag = -1;
+			if (!dropped) {
+				received++;
+				budget--;
+			}
+		}
+	}
+
+	if (first_frag != -1)
+		bp->rx_tail = first_frag;
+	else
+		bp->rx_tail = tail;
+
+	return received;
+}
+
+static int macb_poll(struct net_device *dev, int *budget)
+{
+	struct macb *bp = netdev_priv(dev);
+	int orig_budget, work_done, retval = 0;
+	u32 status;
+
+	status = macb_readl(bp, RSR);
+	macb_writel(bp, RSR, status);
+
+	if (!status) {
+		/*
+		 * This may happen if an interrupt was pending before
+		 * this function was called last time, and no packets
+		 * have been received since.
+		 */
+		netif_rx_complete(dev);
+		goto out;
+	}
+
+	dev_dbg(&bp->pdev->dev, "poll: status = %08lx, budget = %d\n",
+		(unsigned long)status, *budget);
+
+	if (!(status & MACB_BIT(REC))) {
+		dev_warn(&bp->pdev->dev,
+			 "No RX buffers complete, status = %02lx\n",
+			 (unsigned long)status);
+		netif_rx_complete(dev);
+		goto out;
+	}
+
+	orig_budget = *budget;
+	if (orig_budget > dev->quota)
+		orig_budget = dev->quota;
+
+	work_done = macb_rx(bp, orig_budget);
+	if (work_done < orig_budget) {
+		netif_rx_complete(dev);
+		retval = 0;
+	} else {
+		retval = 1;
+	}
+
+	/*
+	 * We've done what we can to clean the buffers. Make sure we
+	 * get notified when new packets arrive.
+	 */
+out:
+	macb_writel(bp, IER, MACB_RX_INT_FLAGS);
+
+	/* TODO: Handle errors */
+
+	return retval;
+}
+
+static irqreturn_t macb_interrupt(int irq, void *dev_id)
+{
+	struct net_device *dev = dev_id;
+	struct macb *bp = netdev_priv(dev);
+	u32 status;
+
+	status = macb_readl(bp, ISR);
+
+	if (unlikely(!status))
+		return IRQ_NONE;
+
+	spin_lock(&bp->lock);
+
+	while (status) {
+		if (status & MACB_BIT(MFD))
+			complete(&bp->mdio_complete);
+
+		/* close possible race with dev_close */
+		if (unlikely(!netif_running(dev))) {
+			macb_writel(bp, IDR, ~0UL);
+			break;
+		}
+
+		if (status & MACB_RX_INT_FLAGS) {
+			if (netif_rx_schedule_prep(dev)) {
+				/*
+				 * There's no point taking any more interrupts
+				 * until we have processed the buffers
+				 */
+				macb_writel(bp, IDR, MACB_RX_INT_FLAGS);
+				dev_dbg(&bp->pdev->dev, "scheduling RX softirq\n");
+				__netif_rx_schedule(dev);
+			}
+		}
+
+		if (status & (MACB_BIT(TCOMP) | MACB_BIT(ISR_TUND)))
+			macb_tx(bp);
+
+		/*
+		 * Link change detection isn't possible with RMII, so we'll
+		 * add that if/when we get our hands on a full-blown MII PHY.
+		 */
+
+		if (status & MACB_BIT(HRESP)) {
+			/*
+			 * TODO: Reset the hardware, and maybe move the printk
+			 * to a lower-priority context as well (work queue?)
+			 */
+			printk(KERN_ERR "%s: DMA bus error: HRESP not OK\n",
+			       dev->name);
+		}
+
+		status = macb_readl(bp, ISR);
+	}
+
+	spin_unlock(&bp->lock);
+
+	return IRQ_HANDLED;
+}
+
+static int macb_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct macb *bp = netdev_priv(dev);
+	dma_addr_t mapping;
+	unsigned int len, entry;
+	u32 ctrl;
+
+#ifdef DEBUG
+	int i;
+	dev_dbg(&bp->pdev->dev,
+		"start_xmit: len %u head %p data %p tail %p end %p\n",
+		skb->len, skb->head, skb->data, skb->tail, skb->end);
+	dev_dbg(&bp->pdev->dev,
+		"data:");
+	for (i = 0; i < 16; i++)
+		printk(" %02x", (unsigned int)skb->data[i]);
+	printk("\n");
+#endif
+
+	len = skb->len;
+	spin_lock_irq(&bp->lock);
+
+	/* This is a hard error, log it. */
+	if (TX_BUFFS_AVAIL(bp) < 1) {
+		netif_stop_queue(dev);
+		spin_unlock_irq(&bp->lock);
+		dev_err(&bp->pdev->dev,
+			"BUG! Tx Ring full when queue awake!\n");
+		dev_dbg(&bp->pdev->dev, "tx_head = %u, tx_tail = %u\n",
+			bp->tx_head, bp->tx_tail);
+		return 1;
+	}
+
+	entry = bp->tx_head;
+	dev_dbg(&bp->pdev->dev, "Allocated ring entry %u\n", entry);
+	mapping = dma_map_single(&bp->pdev->dev, skb->data,
+				 len, DMA_TO_DEVICE);
+	bp->tx_skb[entry].skb = skb;
+	bp->tx_skb[entry].mapping = mapping;
+	dev_dbg(&bp->pdev->dev, "Mapped skb data %p to DMA addr %08lx\n",
+		skb->data, (unsigned long)mapping);
+
+	ctrl = MACB_BF(TX_FRMLEN, len);
+	ctrl |= MACB_BIT(TX_LAST);
+	if (entry == (TX_RING_SIZE - 1))
+		ctrl |= MACB_BIT(TX_WRAP);
+
+	bp->tx_ring[entry].addr = mapping;
+	bp->tx_ring[entry].ctrl = ctrl;
+	wmb();
+
+	entry = NEXT_TX(entry);
+	bp->tx_head = entry;
+
+	macb_writel(bp, NCR, macb_readl(bp, NCR) | MACB_BIT(TSTART));
+
+	if (TX_BUFFS_AVAIL(bp) < 1)
+		netif_stop_queue(dev);
+
+	spin_unlock_irq(&bp->lock);
+
+	dev->trans_start = jiffies;
+
+	return 0;
+}
+
+static void macb_free_consistent(struct macb *bp)
+{
+	if (bp->tx_skb) {
+		kfree(bp->tx_skb);
+		bp->tx_skb = NULL;
+	}
+	if (bp->rx_ring) {
+		dma_free_coherent(&bp->pdev->dev, RX_RING_BYTES,
+				  bp->rx_ring, bp->rx_ring_dma);
+		bp->rx_ring = NULL;
+	}
+	if (bp->tx_ring) {
+		dma_free_coherent(&bp->pdev->dev, TX_RING_BYTES,
+				  bp->tx_ring, bp->tx_ring_dma);
+		bp->tx_ring = NULL;
+	}
+	if (bp->rx_buffers) {
+		dma_free_coherent(&bp->pdev->dev,
+				  RX_RING_SIZE * RX_BUFFER_SIZE,
+				  bp->rx_buffers, bp->rx_buffers_dma);
+		bp->rx_buffers = NULL;
+	}
+}
+
+static int macb_alloc_consistent(struct macb *bp)
+{
+	int size;
+
+	size = TX_RING_SIZE * sizeof(struct ring_info);
+	bp->tx_skb = kmalloc(size, GFP_KERNEL);
+	if (!bp->tx_skb)
+		goto out_err;
+
+	size = RX_RING_BYTES;
+	bp->rx_ring = dma_alloc_coherent(&bp->pdev->dev, size,
+					 &bp->rx_ring_dma, GFP_KERNEL);
+	if (!bp->rx_ring)
+		goto out_err;
+	dev_dbg(&bp->pdev->dev,
+		"Allocated RX ring of %d bytes at %08lx (mapped %p)\n",
+		size, (unsigned long)bp->rx_ring_dma, bp->rx_ring);
+
+	size = TX_RING_BYTES;
+	bp->tx_ring = dma_alloc_coherent(&bp->pdev->dev, size,
+					 &bp->tx_ring_dma, GFP_KERNEL);
+	if (!bp->tx_ring)
+		goto out_err;
+	dev_dbg(&bp->pdev->dev,
+		"Allocated TX ring of %d bytes at %08lx (mapped %p)\n",
+		size, (unsigned long)bp->tx_ring_dma, bp->tx_ring);
+
+	size = RX_RING_SIZE * RX_BUFFER_SIZE;
+	bp->rx_buffers = dma_alloc_coherent(&bp->pdev->dev, size,
+					    &bp->rx_buffers_dma, GFP_KERNEL);
+	if (!bp->rx_buffers)
+		goto out_err;
+	dev_dbg(&bp->pdev->dev,
+		"Allocated RX buffers of %d bytes at %08lx (mapped %p)\n",
+		size, (unsigned long)bp->rx_buffers_dma, bp->rx_buffers);
+
+	return 0;
+
+out_err:
+	macb_free_consistent(bp);
+	return -ENOMEM;
+}
+
+static void macb_init_rings(struct macb *bp)
+{
+	int i;
+	dma_addr_t addr;
+
+	addr = bp->rx_buffers_dma;
+	for (i = 0; i < RX_RING_SIZE; i++) {
+		bp->rx_ring[i].addr = addr;
+		bp->rx_ring[i].ctrl = 0;
+		addr += RX_BUFFER_SIZE;
+	}
+	bp->rx_ring[RX_RING_SIZE - 1].addr |= MACB_BIT(RX_WRAP);
+
+	for (i = 0; i < TX_RING_SIZE; i++) {
+		bp->tx_ring[i].addr = 0;
+		bp->tx_ring[i].ctrl = MACB_BIT(TX_USED);
+	}
+	bp->tx_ring[TX_RING_SIZE - 1].ctrl |= MACB_BIT(TX_WRAP);
+
+	bp->rx_tail = bp->tx_head = bp->tx_tail = 0;
+}
+
+static void macb_reset_hw(struct macb *bp)
+{
+	/* Make sure we have the write buffer for ourselves */
+	wmb();
+
+	/*
+	 * Disable RX and TX (XXX: Should we halt the transmission
+	 * more gracefully?)
+	 */
+	macb_writel(bp, NCR, 0);
+
+	/* Clear the stats registers (XXX: Update stats first?) */
+	macb_writel(bp, NCR, MACB_BIT(CLRSTAT));
+
+	/* Clear all status flags */
+	macb_writel(bp, TSR, ~0UL);
+	macb_writel(bp, RSR, ~0UL);
+
+	/* Disable all interrupts */
+	macb_writel(bp, IDR, ~0UL);
+	macb_readl(bp, ISR);
+}
+
+static void macb_init_hw(struct macb *bp)
+{
+	u32 config;
+
+	macb_reset_hw(bp);
+	__macb_set_hwaddr(bp);
+
+	config = macb_readl(bp, NCFGR) & MACB_BF(CLK, -1L);
+	config |= MACB_BIT(PAE);		/* PAuse Enable */
+	config |= MACB_BIT(DRFCS);		/* Discard Rx FCS */
+	if (bp->dev->flags & IFF_PROMISC)
+		config |= MACB_BIT(CAF);	/* Copy All Frames */
+	if (!(bp->dev->flags & IFF_BROADCAST))
+		config |= MACB_BIT(NBC);	/* No BroadCast */
+	macb_writel(bp, NCFGR, config);
+
+	/* Initialize TX and RX buffers */
+	macb_writel(bp, RBQP, bp->rx_ring_dma);
+	macb_writel(bp, TBQP, bp->tx_ring_dma);
+
+	/* Enable TX and RX */
+	macb_writel(bp, NCR, MACB_BIT(RE) | MACB_BIT(TE));
+
+	/* Enable interrupts */
+	macb_writel(bp, IER, (MACB_BIT(RCOMP)
+			      | MACB_BIT(RXUBR)
+			      | MACB_BIT(ISR_TUND)
+			      | MACB_BIT(ISR_RLE)
+			      | MACB_BIT(TXERR)
+			      | MACB_BIT(TCOMP)
+			      | MACB_BIT(ISR_ROVR)
+			      | MACB_BIT(HRESP)));
+}
+
+static void macb_init_phy(struct net_device *dev)
+{
+	struct macb *bp = netdev_priv(dev);
+
+	/* Set some reasonable default settings */
+	macb_mdio_write(dev, bp->mii.phy_id, MII_ADVERTISE,
+			ADVERTISE_CSMA | ADVERTISE_ALL);
+	macb_mdio_write(dev, bp->mii.phy_id, MII_BMCR,
+			(BMCR_SPEED100 | BMCR_ANENABLE
+			 | BMCR_ANRESTART | BMCR_FULLDPLX));
+}
+
+static int macb_open(struct net_device *dev)
+{
+	struct macb *bp = netdev_priv(dev);
+	int err;
+
+	dev_dbg(&bp->pdev->dev, "open\n");
+
+	if (!is_valid_ether_addr(dev->dev_addr))
+		return -EADDRNOTAVAIL;
+
+	err = macb_alloc_consistent(bp);
+	if (err) {
+		printk(KERN_ERR
+		       "%s: Unable to allocate DMA memory (error %d)\n",
+		       dev->name, err);
+		return err;
+	}
+
+	macb_init_rings(bp);
+	macb_init_hw(bp);
+	macb_init_phy(dev);
+
+	macb_check_media(bp, 1, 1);
+	netif_start_queue(dev);
+
+	schedule_delayed_work(&bp->periodic_task, HZ);
+
+	return 0;
+}
+
+static int macb_close(struct net_device *dev)
+{
+	struct macb *bp = netdev_priv(dev);
+	unsigned long flags;
+
+	cancel_rearming_delayed_work(&bp->periodic_task);
+
+	netif_stop_queue(dev);
+
+	spin_lock_irqsave(&bp->lock, flags);
+	macb_reset_hw(bp);
+	netif_carrier_off(dev);
+	spin_unlock_irqrestore(&bp->lock, flags);
+
+	macb_free_consistent(bp);
+
+	return 0;
+}
+
+static struct net_device_stats *macb_get_stats(struct net_device *dev)
+{
+	struct macb *bp = netdev_priv(dev);
+	struct net_device_stats *nstat = &bp->stats;
+	struct macb_stats *hwstat = &bp->hw_stats;
+
+	/* Convert HW stats into netdevice stats */
+	nstat->rx_errors = (hwstat->rx_fcs_errors +
+			    hwstat->rx_align_errors +
+			    hwstat->rx_resource_errors +
+			    hwstat->rx_overruns +
+			    hwstat->rx_oversize_pkts +
+			    hwstat->rx_jabbers +
+			    hwstat->rx_undersize_pkts +
+			    hwstat->sqe_test_errors +
+			    hwstat->rx_length_mismatch);
+	nstat->tx_errors = (hwstat->tx_late_cols +
+			    hwstat->tx_excessive_cols +
+			    hwstat->tx_underruns +
+			    hwstat->tx_carrier_errors);
+	nstat->collisions = (hwstat->tx_single_cols +
+			     hwstat->tx_multiple_cols +
+			     hwstat->tx_excessive_cols);
+	nstat->rx_length_errors = (hwstat->rx_oversize_pkts +
+				   hwstat->rx_jabbers +
+				   hwstat->rx_undersize_pkts +
+				   hwstat->rx_length_mismatch);
+	nstat->rx_over_errors = hwstat->rx_resource_errors;
+	nstat->rx_crc_errors = hwstat->rx_fcs_errors;
+	nstat->rx_frame_errors = hwstat->rx_align_errors;
+	nstat->rx_fifo_errors = hwstat->rx_overruns;
+	/* XXX: What does "missed" mean? */
+	nstat->tx_aborted_errors = hwstat->tx_excessive_cols;
+	nstat->tx_carrier_errors = hwstat->tx_carrier_errors;
+	nstat->tx_fifo_errors = hwstat->tx_underruns;
+	/* Don't know about heartbeat or window errors... */
+
+	return nstat;
+}
+
+static int macb_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
+{
+	struct macb *bp = netdev_priv(dev);
+	int ret;
+	unsigned long flags;
+
+	spin_lock_irqsave(&bp->lock, flags);
+	ret = mii_ethtool_gset(&bp->mii, cmd);
+	spin_unlock_irqrestore(&bp->lock, flags);
+
+	return ret;
+}
+
+static int macb_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
+{
+	struct macb *bp = netdev_priv(dev);
+	int ret;
+	unsigned long flags;
+
+	spin_lock_irqsave(&bp->lock, flags);
+	ret = mii_ethtool_sset(&bp->mii, cmd);
+	spin_unlock_irqrestore(&bp->lock, flags);
+
+	return ret;
+}
+
+static void macb_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
+{
+	struct macb *bp = netdev_priv(dev);
+
+	strcpy(info->driver, bp->pdev->dev.driver->name);
+	strcpy(info->version, "$Revision: 1.14 $");
+	strcpy(info->bus_info, bp->pdev->dev.bus_id);
+}
+
+static int macb_nway_reset(struct net_device *dev)
+{
+	struct macb *bp = netdev_priv(dev);
+	return mii_nway_restart(&bp->mii);
+}
+
+static struct ethtool_ops macb_ethtool_ops = {
+	.get_settings		= macb_get_settings,
+	.set_settings		= macb_set_settings,
+	.get_drvinfo		= macb_get_drvinfo,
+	.nway_reset		= macb_nway_reset,
+	.get_link		= ethtool_op_get_link,
+};
+
+static int macb_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
+{
+	struct macb *bp = netdev_priv(dev);
+	int ret;
+	unsigned long flags;
+
+	if (!netif_running(dev))
+		return -EINVAL;
+
+	spin_lock_irqsave(&bp->lock, flags);
+	ret = generic_mii_ioctl(&bp->mii, if_mii(rq), cmd, NULL);
+	spin_unlock_irqrestore(&bp->lock, flags);
+
+	return ret;
+}
+
+static ssize_t macb_mii_show(const struct class_device *cd, char *buf,
+			unsigned long addr)
+{
+	struct net_device *dev = to_net_dev(cd);
+	struct macb *bp = netdev_priv(dev);
+	ssize_t ret = -EINVAL;
+
+	if (netif_running(dev)) {
+		int value;
+		value = macb_mdio_read(dev, bp->mii.phy_id, addr);
+		ret = sprintf(buf, "0x%04x\n", (uint16_t)value);
+	}
+
+	return ret;
+}
+
+#define MII_ENTRY(name, addr)					\
+static ssize_t show_##name(struct class_device *cd, char *buf)	\
+{								\
+	return macb_mii_show(cd, buf, addr);			\
+}								\
+static CLASS_DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
+
+MII_ENTRY(bmcr, MII_BMCR);
+MII_ENTRY(bmsr, MII_BMSR);
+MII_ENTRY(physid1, MII_PHYSID1);
+MII_ENTRY(physid2, MII_PHYSID2);
+MII_ENTRY(advertise, MII_ADVERTISE);
+MII_ENTRY(lpa, MII_LPA);
+MII_ENTRY(expansion, MII_EXPANSION);
+
+static struct attribute *macb_mii_attrs[] = {
+	&class_device_attr_bmcr.attr,
+	&class_device_attr_bmsr.attr,
+	&class_device_attr_physid1.attr,
+	&class_device_attr_physid2.attr,
+	&class_device_attr_advertise.attr,
+	&class_device_attr_lpa.attr,
+	&class_device_attr_expansion.attr,
+	NULL,
+};
+
+static struct attribute_group macb_mii_group = {
+	.name	= "mii",
+	.attrs	= macb_mii_attrs,
+};
+
+static void macb_unregister_sysfs(struct net_device *net)
+{
+	struct class_device *class_dev = &net->class_dev;
+
+	sysfs_remove_group(&class_dev->kobj, &macb_mii_group);
+}
+
+static int macb_register_sysfs(struct net_device *net)
+{
+	struct class_device *class_dev = &net->class_dev;
+	int ret;
+
+	ret = sysfs_create_group(&class_dev->kobj, &macb_mii_group);
+	if (ret)
+		printk(KERN_WARNING
+		       "%s: sysfs mii attribute registration failed: %d\n",
+		       net->name, ret);
+	return ret;
+}
+static int __devinit macb_probe(struct platform_device *pdev)
+{
+	struct eth_platform_data *pdata;
+	struct resource *regs;
+	struct net_device *dev;
+	struct macb *bp;
+	unsigned long pclk_hz;
+	u32 config;
+	int err = -ENXIO;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs) {
+		dev_err(&pdev->dev, "no mmio resource defined\n");
+		goto err_out;
+	}
+
+	err = -ENOMEM;
+	dev = alloc_etherdev(sizeof(*bp));
+	if (!dev) {
+		dev_err(&pdev->dev, "etherdev alloc failed, aborting.\n");
+		goto err_out;
+	}
+
+	SET_MODULE_OWNER(dev);
+	SET_NETDEV_DEV(dev, &pdev->dev);
+
+	/* TODO: Actually, we have some interesting features... */
+	dev->features |= 0;
+
+	bp = netdev_priv(dev);
+	bp->pdev = pdev;
+	bp->dev = dev;
+
+	spin_lock_init(&bp->lock);
+
+	bp->pclk = clk_get(&pdev->dev, "pclk");
+	if (IS_ERR(bp->pclk)) {
+		dev_err(&pdev->dev, "failed to get pclk\n");
+		goto err_out_free_dev;
+	}
+	bp->hclk = clk_get(&pdev->dev, "hclk");
+	if (IS_ERR(bp->hclk)) {
+		dev_err(&pdev->dev, "failed to get hclk\n");
+		goto err_out_put_pclk;
+	}
+
+	clk_enable(bp->pclk);
+	clk_enable(bp->hclk);
+
+	bp->regs = ioremap(regs->start, regs->end - regs->start + 1);
+	if (!bp->regs) {
+		dev_err(&pdev->dev, "failed to map registers, aborting.\n");
+		err = -ENOMEM;
+		goto err_out_disable_clocks;
+	}
+
+	dev->irq = platform_get_irq(pdev, 0);
+	err = request_irq(dev->irq, macb_interrupt, SA_SAMPLE_RANDOM,
+			  dev->name, dev);
+	if (err) {
+		printk(KERN_ERR
+		       "%s: Unable to request IRQ %d (error %d)\n",
+		       dev->name, dev->irq, err);
+		goto err_out_iounmap;
+	}
+
+	dev->open = macb_open;
+	dev->stop = macb_close;
+	dev->hard_start_xmit = macb_start_xmit;
+	dev->get_stats = macb_get_stats;
+	dev->do_ioctl = macb_ioctl;
+	dev->poll = macb_poll;
+	dev->weight = 64;
+	dev->ethtool_ops = &macb_ethtool_ops;
+
+	dev->base_addr = regs->start;
+
+	INIT_WORK(&bp->periodic_task, macb_periodic_task, bp);
+	mutex_init(&bp->mdio_mutex);
+	init_completion(&bp->mdio_complete);
+
+	/* Set MII management clock divider */
+	pclk_hz = clk_get_rate(bp->pclk);
+	if (pclk_hz <= 20000000)
+		config = MACB_BF(CLK, MACB_CLK_DIV8);
+	else if (pclk_hz <= 40000000)
+		config = MACB_BF(CLK, MACB_CLK_DIV16);
+	else if (pclk_hz <= 80000000)
+		config = MACB_BF(CLK, MACB_CLK_DIV32);
+	else
+		config = MACB_BF(CLK, MACB_CLK_DIV64);
+	macb_writel(bp, NCFGR, config);
+
+	bp->mii.dev = dev;
+	bp->mii.mdio_read = macb_mdio_read;
+	bp->mii.mdio_write = macb_mdio_write;
+	bp->mii.phy_id_mask = 0x1f;
+	bp->mii.reg_num_mask = 0x1f;
+
+	macb_get_hwaddr(bp);
+	err = macb_phy_probe(bp);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to detect PHY, aborting.\n");
+		goto err_out_free_irq;
+	}
+
+	pdata = pdev->dev.platform_data;
+	if (pdata && pdata->is_rmii)
+		macb_writel(bp, USRIO, 0);
+	else
+		macb_writel(bp, USRIO, MACB_BIT(MII));
+
+	bp->tx_pending = DEF_TX_RING_PENDING;
+
+	err = register_netdev(dev);
+	if (err) {
+		dev_err(&pdev->dev, "Cannot register net device, aborting.\n");
+		goto err_out_free_irq;
+	}
+
+	platform_set_drvdata(pdev, dev);
+
+	macb_register_sysfs(dev);
+
+	printk(KERN_INFO "%s: Atmel MACB at 0x%08lx irq %d "
+	       "(%02x:%02x:%02x:%02x:%02x:%02x)\n",
+	       dev->name, dev->base_addr, dev->irq,
+	       dev->dev_addr[0], dev->dev_addr[1], dev->dev_addr[2],
+	       dev->dev_addr[3], dev->dev_addr[4], dev->dev_addr[5]);
+
+	return 0;
+
+err_out_free_irq:
+	free_irq(dev->irq, dev);
+err_out_iounmap:
+	iounmap(bp->regs);
+err_out_disable_clocks:
+	clk_disable(bp->hclk);
+	clk_disable(bp->pclk);
+	clk_put(bp->hclk);
+err_out_put_pclk:
+	clk_put(bp->pclk);
+err_out_free_dev:
+	free_netdev(dev);
+err_out:
+	platform_set_drvdata(pdev, NULL);
+	return err;
+}
+
+static int __devexit macb_remove(struct platform_device *pdev)
+{
+	struct net_device *dev;
+	struct macb *bp;
+
+	dev = platform_get_drvdata(pdev);
+
+	if (dev) {
+		bp = netdev_priv(dev);
+		macb_unregister_sysfs(dev);
+		unregister_netdev(dev);
+		free_irq(dev->irq, dev);
+		iounmap(bp->regs);
+		clk_disable(bp->hclk);
+		clk_disable(bp->pclk);
+		clk_put(bp->hclk);
+		clk_put(bp->pclk);
+		free_netdev(dev);
+		platform_set_drvdata(pdev, NULL);
+	}
+
+	return 0;
+}
+
+static struct platform_driver macb_driver = {
+	.probe		= macb_probe,
+	.remove		= __devexit_p(macb_remove),
+	.driver		= {
+		.name		= "macb",
+	},
+};
+
+static int __init macb_init(void)
+{
+	return platform_driver_register(&macb_driver);
+}
+
+static void __exit macb_exit(void)
+{
+	platform_driver_unregister(&macb_driver);
+}
+
+module_init(macb_init);
+module_exit(macb_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Atmel MACB Ethernet driver");
+MODULE_AUTHOR("Haavard Skinnemoen <hskinnemoen@atmel.com>");