[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>");