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[hh.org.git] / drivers / net / macb.c

/*
 * 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>");