/*
 *
 * Alchemy Au1x00 ethernet driver
 *
 * Copyright 2001-2003, 2006 MontaVista Software Inc.
 * Copyright 2002 TimeSys Corp.
 * Added ethtool/mii-tool support,
 * Copyright 2004 Matt Porter <mporter@kernel.crashing.org>
 * Update: 2004 Bjoern Riemer, riemer@fokus.fraunhofer.de
 * or riemer@riemer-nt.de: fixed the link beat detection with
 * ioctls (SIOCGMIIPHY)
 * Copyright 2006 Herbert Valerio Riedel <hvr@gnu.org>
 *  converted to use linux-2.6.x's PHY framework
 *
 * Author: MontaVista Software, Inc.
 *              ppopov@mvista.com or source@mvista.com
 *
 * ########################################################################
 *
 *  This program is free software; you can distribute it and/or modify it
 *  under the terms of the GNU General Public License (Version 2) as
 *  published by the Free Software Foundation.
 *
 *  This program is distributed in the hope it will be useful, but WITHOUT
 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 *  for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 * ########################################################################
 *
 *
 */
#include <linux/capability.h>
#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/errno.h>
#include <linux/in.h>
#include <linux/ioport.h>
#include <linux/bitops.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/mii.h>
#include <linux/skbuff.h>
#include <linux/delay.h>
#include <linux/crc32.h>
#include <linux/phy.h>

#include <asm/cpu.h>
#include <asm/mipsregs.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/processor.h>

#include <au1000.h>
#include <prom.h>

#include "au1000_eth.h"

#ifdef AU1000_ETH_DEBUG
static int au1000_debug = 5;
#else
static int au1000_debug = 3;
#endif

#define DRV_NAME        "au1000_eth"
#define DRV_VERSION     "1.6"
#define DRV_AUTHOR      "Pete Popov <ppopov@embeddedalley.com>"
#define DRV_DESC        "Au1xxx on-chip Ethernet driver"

MODULE_AUTHOR(DRV_AUTHOR);
MODULE_DESCRIPTION(DRV_DESC);
MODULE_LICENSE("GPL");

/*
 * Theory of operation
 *
 * The Au1000 MACs use a simple rx and tx descriptor ring scheme.
 * There are four receive and four transmit descriptors.  These
 * descriptors are not in memory; rather, they are just a set of
 * hardware registers.
 *
 * Since the Au1000 has a coherent data cache, the receive and
 * transmit buffers are allocated from the KSEG0 segment. The
 * hardware registers, however, are still mapped at KSEG1 to
 * make sure there's no out-of-order writes, and that all writes
 * complete immediately.
 */

/* These addresses are only used if yamon doesn't tell us what
 * the mac address is, and the mac address is not passed on the
 * command line.
 */
static unsigned char au1000_mac_addr[6] __devinitdata = {
        0x00, 0x50, 0xc2, 0x0c, 0x30, 0x00
};

struct au1000_private *au_macs[NUM_ETH_INTERFACES];

/*
 * board-specific configurations
 *
 * PHY detection algorithm
 *
 * If AU1XXX_PHY_STATIC_CONFIG is undefined, the PHY setup is
 * autodetected:
 *
 * mii_probe() first searches the current MAC's MII bus for a PHY,
 * selecting the first (or last, if AU1XXX_PHY_SEARCH_HIGHEST_ADDR is
 * defined) PHY address not already claimed by another netdev.
 *
 * If nothing was found that way when searching for the 2nd ethernet
 * controller's PHY and AU1XXX_PHY1_SEARCH_ON_MAC0 is defined, then
 * the first MII bus is searched as well for an unclaimed PHY; this is
 * needed in case of a dual-PHY accessible only through the MAC0's MII
 * bus.
 *
 * Finally, if no PHY is found, then the corresponding ethernet
 * controller is not registered to the network subsystem.
 */

/* autodetection defaults */
#undef  AU1XXX_PHY_SEARCH_HIGHEST_ADDR
#define AU1XXX_PHY1_SEARCH_ON_MAC0

/* static PHY setup
 *
 * most boards PHY setup should be detectable properly with the
 * autodetection algorithm in mii_probe(), but in some cases (e.g. if
 * you have a switch attached, or want to use the PHY's interrupt
 * notification capabilities) you can provide a static PHY
 * configuration here
 *
 * IRQs may only be set, if a PHY address was configured
 * If a PHY address is given, also a bus id is required to be set
 *
 * ps: make sure the used irqs are configured properly in the board
 * specific irq-map
 */

#if defined(CONFIG_MIPS_BOSPORUS)
/*
 * Micrel/Kendin 5 port switch attached to MAC0,
 * MAC0 is associated with PHY address 5 (== WAN port)
 * MAC1 is not associated with any PHY, since it's connected directly
 * to the switch.
 * no interrupts are used
 */
# define AU1XXX_PHY_STATIC_CONFIG

# define AU1XXX_PHY0_ADDR  5
# define AU1XXX_PHY0_BUSID 0
#  undef AU1XXX_PHY0_IRQ

#  undef AU1XXX_PHY1_ADDR
#  undef AU1XXX_PHY1_BUSID
#  undef AU1XXX_PHY1_IRQ
#endif

#if defined(AU1XXX_PHY0_BUSID) && (AU1XXX_PHY0_BUSID > 0)
# error MAC0-associated PHY attached 2nd MACs MII bus not supported yet
#endif

static void enable_mac(struct net_device *dev, int force_reset)
{
        unsigned long flags;
        struct au1000_private *aup = netdev_priv(dev);

        spin_lock_irqsave(&aup->lock, flags);

        if(force_reset || (!aup->mac_enabled)) {
                *aup->enable = MAC_EN_CLOCK_ENABLE;
                au_sync_delay(2);
                *aup->enable = (MAC_EN_RESET0 | MAC_EN_RESET1 | MAC_EN_RESET2
                                | MAC_EN_CLOCK_ENABLE);
                au_sync_delay(2);

                aup->mac_enabled = 1;
        }

        spin_unlock_irqrestore(&aup->lock, flags);
}

/*
 * MII operations
 */
static int au1000_mdio_read(struct net_device *dev, int phy_addr, int reg)
{
        struct au1000_private *aup = netdev_priv(dev);
        volatile u32 *const mii_control_reg = &aup->mac->mii_control;
        volatile u32 *const mii_data_reg = &aup->mac->mii_data;
        u32 timedout = 20;
        u32 mii_control;

        while (*mii_control_reg & MAC_MII_BUSY) {
                mdelay(1);
                if (--timedout == 0) {
                        printk(KERN_ERR "%s: read_MII busy timeout!!\n",
                                        dev->name);
                        return -1;
                }
        }

        mii_control = MAC_SET_MII_SELECT_REG(reg) |
                MAC_SET_MII_SELECT_PHY(phy_addr) | MAC_MII_READ;

        *mii_control_reg = mii_control;

        timedout = 20;
        while (*mii_control_reg & MAC_MII_BUSY) {
                mdelay(1);
                if (--timedout == 0) {
                        printk(KERN_ERR "%s: mdio_read busy timeout!!\n",
                                        dev->name);
                        return -1;
                }
        }
        return (int)*mii_data_reg;
}

static void au1000_mdio_write(struct net_device *dev, int phy_addr,
                              int reg, u16 value)
{
        struct au1000_private *aup = netdev_priv(dev);
        volatile u32 *const mii_control_reg = &aup->mac->mii_control;
        volatile u32 *const mii_data_reg = &aup->mac->mii_data;
        u32 timedout = 20;
        u32 mii_control;

        while (*mii_control_reg & MAC_MII_BUSY) {
                mdelay(1);
                if (--timedout == 0) {
                        printk(KERN_ERR "%s: mdio_write busy timeout!!\n",
                                        dev->name);
                        return;
                }
        }

        mii_control = MAC_SET_MII_SELECT_REG(reg) |
                MAC_SET_MII_SELECT_PHY(phy_addr) | MAC_MII_WRITE;

        *mii_data_reg = value;
        *mii_control_reg = mii_control;
}

static int au1000_mdiobus_read(struct mii_bus *bus, int phy_addr, int regnum)
{
        /* WARNING: bus->phy_map[phy_addr].attached_dev == dev does
         * _NOT_ hold (e.g. when PHY is accessed through other MAC's MII bus) */
        struct net_device *const dev = bus->priv;

        enable_mac(dev, 0); /* make sure the MAC associated with this
                             * mii_bus is enabled */
        return au1000_mdio_read(dev, phy_addr, regnum);
}

static int au1000_mdiobus_write(struct mii_bus *bus, int phy_addr, int regnum,
                                u16 value)
{
        struct net_device *const dev = bus->priv;

        enable_mac(dev, 0); /* make sure the MAC associated with this
                             * mii_bus is enabled */
        au1000_mdio_write(dev, phy_addr, regnum, value);
        return 0;
}

static int au1000_mdiobus_reset(struct mii_bus *bus)
{
        struct net_device *const dev = bus->priv;

        enable_mac(dev, 0); /* make sure the MAC associated with this
                             * mii_bus is enabled */
        return 0;
}

static void hard_stop(struct net_device *dev)
{
        struct au1000_private *aup = netdev_priv(dev);

        if (au1000_debug > 4)
                printk(KERN_INFO "%s: hard stop\n", dev->name);

        aup->mac->control &= ~(MAC_RX_ENABLE | MAC_TX_ENABLE);
        au_sync_delay(10);
}

static void enable_rx_tx(struct net_device *dev)
{
        struct au1000_private *aup = netdev_priv(dev);

        if (au1000_debug > 4)
                printk(KERN_INFO "%s: enable_rx_tx\n", dev->name);

        aup->mac->control |= (MAC_RX_ENABLE | MAC_TX_ENABLE);
        au_sync_delay(10);
}

static void
au1000_adjust_link(struct net_device *dev)
{
        struct au1000_private *aup = netdev_priv(dev);
        struct phy_device *phydev = aup->phy_dev;
        unsigned long flags;

        int status_change = 0;

        BUG_ON(!aup->phy_dev);

        spin_lock_irqsave(&aup->lock, flags);

        if (phydev->link && (aup->old_speed != phydev->speed)) {
                // speed changed

                switch(phydev->speed) {
                case SPEED_10:
                case SPEED_100:
                        break;
                default:
                        printk(KERN_WARNING
                               "%s: Speed (%d) is not 10/100 ???\n",
                               dev->name, phydev->speed);
                        break;
                }

                aup->old_speed = phydev->speed;

                status_change = 1;
        }

        if (phydev->link && (aup->old_duplex != phydev->duplex)) {
                // duplex mode changed

                /* switching duplex mode requires to disable rx and tx! */
                hard_stop(dev);

                if (DUPLEX_FULL == phydev->duplex)
                        aup->mac->control = ((aup->mac->control
                                             | MAC_FULL_DUPLEX)
                                             & ~MAC_DISABLE_RX_OWN);
                else
                        aup->mac->control = ((aup->mac->control
                                              & ~MAC_FULL_DUPLEX)
                                             | MAC_DISABLE_RX_OWN);
                au_sync_delay(1);

                enable_rx_tx(dev);
                aup->old_duplex = phydev->duplex;

                status_change = 1;
        }

        if(phydev->link != aup->old_link) {
                // link state changed

                if (!phydev->link) {
                        /* link went down */
                        aup->old_speed = 0;
                        aup->old_duplex = -1;
                }

                aup->old_link = phydev->link;
                status_change = 1;
        }

        spin_unlock_irqrestore(&aup->lock, flags);

        if (status_change) {
                if (phydev->link)
                        printk(KERN_INFO "%s: link up (%d/%s)\n",
                               dev->name, phydev->speed,
                               DUPLEX_FULL == phydev->duplex ? "Full" : "Half");
                else
                        printk(KERN_INFO "%s: link down\n", dev->name);
        }
}

static int mii_probe (struct net_device *dev)
{
        struct au1000_private *const aup = netdev_priv(dev);
        struct phy_device *phydev = NULL;

#if defined(AU1XXX_PHY_STATIC_CONFIG)
        BUG_ON(aup->mac_id < 0 || aup->mac_id > 1);

        if(aup->mac_id == 0) { /* get PHY0 */
# if defined(AU1XXX_PHY0_ADDR)
                phydev = au_macs[AU1XXX_PHY0_BUSID]->mii_bus->phy_map[AU1XXX_PHY0_ADDR];
# else
                printk (KERN_INFO DRV_NAME ":%s: using PHY-less setup\n",
                        dev->name);
                return 0;
# endif /* defined(AU1XXX_PHY0_ADDR) */
        } else if (aup->mac_id == 1) { /* get PHY1 */
# if defined(AU1XXX_PHY1_ADDR)
                phydev = au_macs[AU1XXX_PHY1_BUSID]->mii_bus->phy_map[AU1XXX_PHY1_ADDR];
# else
                printk (KERN_INFO DRV_NAME ":%s: using PHY-less setup\n",
                        dev->name);
                return 0;
# endif /* defined(AU1XXX_PHY1_ADDR) */
        }

#else /* defined(AU1XXX_PHY_STATIC_CONFIG) */
        int phy_addr;

        /* find the first (lowest address) PHY on the current MAC's MII bus */
        for (phy_addr = 0; phy_addr < PHY_MAX_ADDR; phy_addr++)
                if (aup->mii_bus->phy_map[phy_addr]) {
                        phydev = aup->mii_bus->phy_map[phy_addr];
# if !defined(AU1XXX_PHY_SEARCH_HIGHEST_ADDR)
                        break; /* break out with first one found */
# endif
                }

# if defined(AU1XXX_PHY1_SEARCH_ON_MAC0)
        /* try harder to find a PHY */
        if (!phydev && (aup->mac_id == 1)) {
                /* no PHY found, maybe we have a dual PHY? */
                printk (KERN_INFO DRV_NAME ": no PHY found on MAC1, "
                        "let's see if it's attached to MAC0...\n");

                BUG_ON(!au_macs[0]);

                /* find the first (lowest address) non-attached PHY on
                 * the MAC0 MII bus */
                for (phy_addr = 0; phy_addr < PHY_MAX_ADDR; phy_addr++) {
                        struct phy_device *const tmp_phydev =
                                au_macs[0]->mii_bus->phy_map[phy_addr];

                        if (!tmp_phydev)
                                continue; /* no PHY here... */

                        if (tmp_phydev->attached_dev)
                                continue; /* already claimed by MAC0 */

                        phydev = tmp_phydev;
                        break; /* found it */
                }
        }
# endif /* defined(AU1XXX_PHY1_SEARCH_OTHER_BUS) */

#endif /* defined(AU1XXX_PHY_STATIC_CONFIG) */
        if (!phydev) {
                printk (KERN_ERR DRV_NAME ":%s: no PHY found\n", dev->name);
                return -1;
        }

        /* now we are supposed to have a proper phydev, to attach to... */
        BUG_ON(phydev->attached_dev);

        phydev = phy_connect(dev, dev_name(&phydev->dev), &au1000_adjust_link,
                        0, PHY_INTERFACE_MODE_MII);

        if (IS_ERR(phydev)) {
                printk(KERN_ERR "%s: Could not attach to PHY\n", dev->name);
                return PTR_ERR(phydev);
        }

        /* mask with MAC supported features */
        phydev->supported &= (SUPPORTED_10baseT_Half
                              | SUPPORTED_10baseT_Full
                              | SUPPORTED_100baseT_Half
                              | SUPPORTED_100baseT_Full
                              | SUPPORTED_Autoneg
                              /* | SUPPORTED_Pause | SUPPORTED_Asym_Pause */
                              | SUPPORTED_MII
                              | SUPPORTED_TP);

        phydev->advertising = phydev->supported;

        aup->old_link = 0;
        aup->old_speed = 0;
        aup->old_duplex = -1;
        aup->phy_dev = phydev;

        printk(KERN_INFO "%s: attached PHY driver [%s] "
               "(mii_bus:phy_addr=%s, irq=%d)\n", dev->name,
               phydev->drv->name, dev_name(&phydev->dev), phydev->irq);

        return 0;
}


/*
 * Buffer allocation/deallocation routines. The buffer descriptor returned
 * has the virtual and dma address of a buffer suitable for
 * both, receive and transmit operations.
 */
static db_dest_t *GetFreeDB(struct au1000_private *aup)
{
        db_dest_t *pDB;
        pDB = aup->pDBfree;

        if (pDB) {
                aup->pDBfree = pDB->pnext;
        }
        return pDB;
}

void ReleaseDB(struct au1000_private *aup, db_dest_t *pDB)
{
        db_dest_t *pDBfree = aup->pDBfree;
        if (pDBfree)
                pDBfree->pnext = pDB;
        aup->pDBfree = pDB;
}

static void reset_mac_unlocked(struct net_device *dev)
{
        struct au1000_private *const aup = netdev_priv(dev);
        int i;

        hard_stop(dev);

        *aup->enable = MAC_EN_CLOCK_ENABLE;
        au_sync_delay(2);
        *aup->enable = 0;
        au_sync_delay(2);

        aup->tx_full = 0;
        for (i = 0; i < NUM_RX_DMA; i++) {
                /* reset control bits */
                aup->rx_dma_ring[i]->buff_stat &= ~0xf;
        }
        for (i = 0; i < NUM_TX_DMA; i++) {
                /* reset control bits */
                aup->tx_dma_ring[i]->buff_stat &= ~0xf;
        }

        aup->mac_enabled = 0;

}

static void reset_mac(struct net_device *dev)
{
        struct au1000_private *const aup = netdev_priv(dev);
        unsigned long flags;

        if (au1000_debug > 4)
                printk(KERN_INFO "%s: reset mac, aup %x\n",
                       dev->name, (unsigned)aup);

        spin_lock_irqsave(&aup->lock, flags);

        reset_mac_unlocked (dev);

        spin_unlock_irqrestore(&aup->lock, flags);
}

/*
 * Setup the receive and transmit "rings".  These pointers are the addresses
 * of the rx and tx MAC DMA registers so they are fixed by the hardware --
 * these are not descriptors sitting in memory.
 */
static void
setup_hw_rings(struct au1000_private *aup, u32 rx_base, u32 tx_base)
{
        int i;

        for (i = 0; i < NUM_RX_DMA; i++) {
                aup->rx_dma_ring[i] =
                        (volatile rx_dma_t *) (rx_base + sizeof(rx_dma_t)*i);
        }
        for (i = 0; i < NUM_TX_DMA; i++) {
                aup->tx_dma_ring[i] =
                        (volatile tx_dma_t *) (tx_base + sizeof(tx_dma_t)*i);
        }
}

static struct {
        u32 base_addr;
        u32 macen_addr;
        int irq;
        struct net_device *dev;
} iflist[2] = {
#ifdef CONFIG_SOC_AU1000
        {AU1000_ETH0_BASE, AU1000_MAC0_ENABLE, AU1000_MAC0_DMA_INT},
        {AU1000_ETH1_BASE, AU1000_MAC1_ENABLE, AU1000_MAC1_DMA_INT}
#endif
#ifdef CONFIG_SOC_AU1100
        {AU1100_ETH0_BASE, AU1100_MAC0_ENABLE, AU1100_MAC0_DMA_INT}
#endif
#ifdef CONFIG_SOC_AU1500
        {AU1500_ETH0_BASE, AU1500_MAC0_ENABLE, AU1500_MAC0_DMA_INT},
        {AU1500_ETH1_BASE, AU1500_MAC1_ENABLE, AU1500_MAC1_DMA_INT}
#endif
#ifdef CONFIG_SOC_AU1550
        {AU1550_ETH0_BASE, AU1550_MAC0_ENABLE, AU1550_MAC0_DMA_INT},
        {AU1550_ETH1_BASE, AU1550_MAC1_ENABLE, AU1550_MAC1_DMA_INT}
#endif
};

static int num_ifs;

/*
 * ethtool operations
 */

static int au1000_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
        struct au1000_private *aup = netdev_priv(dev);

        if (aup->phy_dev)
                return phy_ethtool_gset(aup->phy_dev, cmd);

        return -EINVAL;
}

static int au1000_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
        struct au1000_private *aup = netdev_priv(dev);

        if (!capable(CAP_NET_ADMIN))
                return -EPERM;

        if (aup->phy_dev)
                return phy_ethtool_sset(aup->phy_dev, cmd);

        return -EINVAL;
}

static void
au1000_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
{
        struct au1000_private *aup = netdev_priv(dev);

        strcpy(info->driver, DRV_NAME);
        strcpy(info->version, DRV_VERSION);
        info->fw_version[0] = '\0';
        sprintf(info->bus_info, "%s %d", DRV_NAME, aup->mac_id);
        info->regdump_len = 0;
}

static const struct ethtool_ops au1000_ethtool_ops = {
        .get_settings = au1000_get_settings,
        .set_settings = au1000_set_settings,
        .get_drvinfo = au1000_get_drvinfo,
        .get_link = ethtool_op_get_link,
};


/*
 * Initialize the interface.
 *
 * When the device powers up, the clocks are disabled and the
 * mac is in reset state.  When the interface is closed, we
 * do the same -- reset the device and disable the clocks to
 * conserve power. Thus, whenever au1000_init() is called,
 * the device should already be in reset state.
 */
static int au1000_init(struct net_device *dev)
{
        struct au1000_private *aup = netdev_priv(dev);
        unsigned long flags;
        int i;
        u32 control;

        if (au1000_debug > 4)
                printk("%s: au1000_init\n", dev->name);

        /* bring the device out of reset */
        enable_mac(dev, 1);

        spin_lock_irqsave(&aup->lock, flags);

        aup->mac->control = 0;
        aup->tx_head = (aup->tx_dma_ring[0]->buff_stat & 0xC) >> 2;
        aup->tx_tail = aup->tx_head;
        aup->rx_head = (aup->rx_dma_ring[0]->buff_stat & 0xC) >> 2;

        aup->mac->mac_addr_high = dev->dev_addr[5]<<8 | dev->dev_addr[4];
        aup->mac->mac_addr_low = dev->dev_addr[3]<<24 | dev->dev_addr[2]<<16 |
                dev->dev_addr[1]<<8 | dev->dev_addr[0];

        for (i = 0; i < NUM_RX_DMA; i++) {
                aup->rx_dma_ring[i]->buff_stat |= RX_DMA_ENABLE;
        }
        au_sync();

        control = MAC_RX_ENABLE | MAC_TX_ENABLE;
#ifndef CONFIG_CPU_LITTLE_ENDIAN
        control |= MAC_BIG_ENDIAN;
#endif
        if (aup->phy_dev) {
                if (aup->phy_dev->link && (DUPLEX_FULL == aup->phy_dev->duplex))
                        control |= MAC_FULL_DUPLEX;
                else
                        control |= MAC_DISABLE_RX_OWN;
        } else { /* PHY-less op, assume full-duplex */
                control |= MAC_FULL_DUPLEX;
        }

        aup->mac->control = control;
        aup->mac->vlan1_tag = 0x8100; /* activate vlan support */
        au_sync();

        spin_unlock_irqrestore(&aup->lock, flags);
        return 0;
}

static inline void update_rx_stats(struct net_device *dev, u32 status)
{
        struct au1000_private *aup = netdev_priv(dev);
        struct net_device_stats *ps = &dev->stats;

        ps->rx_packets++;
        if (status & RX_MCAST_FRAME)
                ps->multicast++;

        if (status & RX_ERROR) {
                ps->rx_errors++;
                if (status & RX_MISSED_FRAME)
                        ps->rx_missed_errors++;
                if (status & (RX_OVERLEN | RX_RUNT | RX_LEN_ERROR))
                        ps->rx_length_errors++;
                if (status & RX_CRC_ERROR)
                        ps->rx_crc_errors++;
                if (status & RX_COLL)
                        ps->collisions++;
        }
        else
                ps->rx_bytes += status & RX_FRAME_LEN_MASK;

}

/*
 * Au1000 receive routine.
 */
static int au1000_rx(struct net_device *dev)
{
        struct au1000_private *aup = netdev_priv(dev);
        struct sk_buff *skb;
        volatile rx_dma_t *prxd;
        u32 buff_stat, status;
        db_dest_t *pDB;
        u32     frmlen;

        if (au1000_debug > 5)
                printk("%s: au1000_rx head %d\n", dev->name, aup->rx_head);

        prxd = aup->rx_dma_ring[aup->rx_head];
        buff_stat = prxd->buff_stat;
        while (buff_stat & RX_T_DONE)  {
                status = prxd->status;
                pDB = aup->rx_db_inuse[aup->rx_head];
                update_rx_stats(dev, status);
                if (!(status & RX_ERROR))  {

                        /* good frame */
                        frmlen = (status & RX_FRAME_LEN_MASK);
                        frmlen -= 4; /* Remove FCS */
                        skb = dev_alloc_skb(frmlen + 2);
                        if (skb == NULL) {
                                printk(KERN_ERR
                                       "%s: Memory squeeze, dropping packet.\n",
                                       dev->name);
                                dev->stats.rx_dropped++;
                                continue;
                        }
                        skb_reserve(skb, 2);    /* 16 byte IP header align */
                        skb_copy_to_linear_data(skb,
                                (unsigned char *)pDB->vaddr, frmlen);
                        skb_put(skb, frmlen);
                        skb->protocol = eth_type_trans(skb, dev);
                        netif_rx(skb);  /* pass the packet to upper layers */
                }
                else {
                        if (au1000_debug > 4) {
                                if (status & RX_MISSED_FRAME)
                                        printk("rx miss\n");
                                if (status & RX_WDOG_TIMER)
                                        printk("rx wdog\n");
                                if (status & RX_RUNT)
                                        printk("rx runt\n");
                                if (status & RX_OVERLEN)
                                        printk("rx overlen\n");
                                if (status & RX_COLL)
                                        printk("rx coll\n");
                                if (status & RX_MII_ERROR)
                                        printk("rx mii error\n");
                                if (status & RX_CRC_ERROR)
                                        printk("rx crc error\n");
                                if (status & RX_LEN_ERROR)
                                        printk("rx len error\n");
                                if (status & RX_U_CNTRL_FRAME)
                                        printk("rx u control frame\n");
                        }
                }
                prxd->buff_stat = (u32)(pDB->dma_addr | RX_DMA_ENABLE);
                aup->rx_head = (aup->rx_head + 1) & (NUM_RX_DMA - 1);
                au_sync();

                /* next descriptor */
                prxd = aup->rx_dma_ring[aup->rx_head];
                buff_stat = prxd->buff_stat;
        }
        return 0;
}

static void update_tx_stats(struct net_device *dev, u32 status)
{
        struct au1000_private *aup = netdev_priv(dev);
        struct net_device_stats *ps = &dev->stats;

        if (status & TX_FRAME_ABORTED) {
                if (!aup->phy_dev || (DUPLEX_FULL == aup->phy_dev->duplex)) {
                        if (status & (TX_JAB_TIMEOUT | TX_UNDERRUN)) {
                                /* any other tx errors are only valid
                                 * in half duplex mode */
                                ps->tx_errors++;
                                ps->tx_aborted_errors++;
                        }
                }
                else {
                        ps->tx_errors++;
                        ps->tx_aborted_errors++;
                        if (status & (TX_NO_CARRIER | TX_LOSS_CARRIER))
                                ps->tx_carrier_errors++;
                }
        }
}

/*
 * Called from the interrupt service routine to acknowledge
 * the TX DONE bits.  This is a must if the irq is setup as
 * edge triggered.
 */
static void au1000_tx_ack(struct net_device *dev)
{
        struct au1000_private *aup = netdev_priv(dev);
        volatile tx_dma_t *ptxd;

        ptxd = aup->tx_dma_ring[aup->tx_tail];

        while (ptxd->buff_stat & TX_T_DONE) {
                update_tx_stats(dev, ptxd->status);
                ptxd->buff_stat &= ~TX_T_DONE;
                ptxd->len = 0;
                au_sync();

                aup->tx_tail = (aup->tx_tail + 1) & (NUM_TX_DMA - 1);
                ptxd = aup->tx_dma_ring[aup->tx_tail];

                if (aup->tx_full) {
                        aup->tx_full = 0;
                        netif_wake_queue(dev);
                }
        }
}

/*
 * Au1000 interrupt service routine.
 */
static irqreturn_t au1000_interrupt(int irq, void *dev_id)
{
        struct net_device *dev = dev_id;

        /* Handle RX interrupts first to minimize chance of overrun */

        au1000_rx(dev);
        au1000_tx_ack(dev);
        return IRQ_RETVAL(1);
}

static int au1000_open(struct net_device *dev)
{
        int retval;
        struct au1000_private *aup = netdev_priv(dev);

        if (au1000_debug > 4)
                printk("%s: open: dev=%p\n", dev->name, dev);

        if ((retval = request_irq(dev->irq, &au1000_interrupt, 0,
                                        dev->name, dev))) {
                printk(KERN_ERR "%s: unable to get IRQ %d\n",
                                dev->name, dev->irq);
                return retval;
        }

        if ((retval = au1000_init(dev))) {
                printk(KERN_ERR "%s: error in au1000_init\n", dev->name);
                free_irq(dev->irq, dev);
                return retval;
        }

        if (aup->phy_dev) {
                /* cause the PHY state machine to schedule a link state check */
                aup->phy_dev->state = PHY_CHANGELINK;
                phy_start(aup->phy_dev);
        }

        netif_start_queue(dev);

        if (au1000_debug > 4)
                printk("%s: open: Initialization done.\n", dev->name);

        return 0;
}

static int au1000_close(struct net_device *dev)
{
        unsigned long flags;
        struct au1000_private *const aup = netdev_priv(dev);

        if (au1000_debug > 4)
                printk("%s: close: dev=%p\n", dev->name, dev);

        if (aup->phy_dev)
                phy_stop(aup->phy_dev);

        spin_lock_irqsave(&aup->lock, flags);

        reset_mac_unlocked (dev);

        /* stop the device */
        netif_stop_queue(dev);

        /* disable the interrupt */
        free_irq(dev->irq, dev);
        spin_unlock_irqrestore(&aup->lock, flags);

        return 0;
}

/*
 * Au1000 transmit routine.
 */
static netdev_tx_t au1000_tx(struct sk_buff *skb, struct net_device *dev)
{
        struct au1000_private *aup = netdev_priv(dev);
        struct net_device_stats *ps = &dev->stats;
        volatile tx_dma_t *ptxd;
        u32 buff_stat;
        db_dest_t *pDB;
        int i;

        if (au1000_debug > 5)
                printk("%s: tx: aup %x len=%d, data=%p, head %d\n",
                                dev->name, (unsigned)aup, skb->len,
                                skb->data, aup->tx_head);

        ptxd = aup->tx_dma_ring[aup->tx_head];
        buff_stat = ptxd->buff_stat;
        if (buff_stat & TX_DMA_ENABLE) {
                /* We've wrapped around and the transmitter is still busy */
                netif_stop_queue(dev);
                aup->tx_full = 1;
                return NETDEV_TX_BUSY;
        }
        else if (buff_stat & TX_T_DONE) {
                update_tx_stats(dev, ptxd->status);
                ptxd->len = 0;
        }

        if (aup->tx_full) {
                aup->tx_full = 0;
                netif_wake_queue(dev);
        }

        pDB = aup->tx_db_inuse[aup->tx_head];
        skb_copy_from_linear_data(skb, pDB->vaddr, skb->len);
        if (skb->len < ETH_ZLEN) {
                for (i=skb->len; i<ETH_ZLEN; i++) {
                        ((char *)pDB->vaddr)[i] = 0;
                }
                ptxd->len = ETH_ZLEN;
        }
        else
                ptxd->len = skb->len;

        ps->tx_packets++;
        ps->tx_bytes += ptxd->len;

        ptxd->buff_stat = pDB->dma_addr | TX_DMA_ENABLE;
        au_sync();
        dev_kfree_skb(skb);
        aup->tx_head = (aup->tx_head + 1) & (NUM_TX_DMA - 1);
        dev->trans_start = jiffies;
        return NETDEV_TX_OK;
}

/*
 * The Tx ring has been full longer than the watchdog timeout
 * value. The transmitter must be hung?
 */
static void au1000_tx_timeout(struct net_device *dev)
{
        printk(KERN_ERR "%s: au1000_tx_timeout: dev=%p\n", dev->name, dev);
        reset_mac(dev);

        au1000_init(dev);
        dev->trans_start = jiffies;
        netif_wake_queue(dev);
}

static void au1000_multicast_list(struct net_device *dev)
{
        struct au1000_private *aup = netdev_priv(dev);

        if (au1000_debug > 4)
                printk("%s: au1000_multicast_list: flags=%x\n", dev->name, dev->flags);

        if (dev->flags & IFF_PROMISC) {                 /* Set promiscuous. */
                aup->mac->control |= MAC_PROMISCUOUS;
        } else if ((dev->flags & IFF_ALLMULTI)  ||
                           dev->mc_count > MULTICAST_FILTER_LIMIT) {
                aup->mac->control |= MAC_PASS_ALL_MULTI;
                aup->mac->control &= ~MAC_PROMISCUOUS;
                printk(KERN_INFO "%s: Pass all multicast\n", dev->name);
        } else {
                int i;
                struct dev_mc_list *mclist;
                u32 mc_filter[2];       /* Multicast hash filter */

                mc_filter[1] = mc_filter[0] = 0;
                for (i = 0, mclist = dev->mc_list; mclist && i < dev->mc_count;
                         i++, mclist = mclist->next) {
                        set_bit(ether_crc(ETH_ALEN, mclist->dmi_addr)>>26,
                                        (long *)mc_filter);
                }
                aup->mac->multi_hash_high = mc_filter[1];
                aup->mac->multi_hash_low = mc_filter[0];
                aup->mac->control &= ~MAC_PROMISCUOUS;
                aup->mac->control |= MAC_HASH_MODE;
        }
}

static int au1000_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
{
        struct au1000_private *aup = netdev_priv(dev);

        if (!netif_running(dev)) return -EINVAL;

        if (!aup->phy_dev) return -EINVAL; // PHY not controllable

        return phy_mii_ioctl(aup->phy_dev, if_mii(rq), cmd);
}

static const struct net_device_ops au1000_netdev_ops = {
        .ndo_open               = au1000_open,
        .ndo_stop               = au1000_close,
        .ndo_start_xmit         = au1000_tx,
        .ndo_set_multicast_list = au1000_multicast_list,
        .ndo_do_ioctl           = au1000_ioctl,
        .ndo_tx_timeout         = au1000_tx_timeout,
        .ndo_set_mac_address    = eth_mac_addr,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_change_mtu         = eth_change_mtu,
};

static struct net_device * au1000_probe(int port_num)
{
        static unsigned version_printed = 0;
        struct au1000_private *aup = NULL;
        struct net_device *dev = NULL;
        db_dest_t *pDB, *pDBfree;
        char ethaddr[6];
        int irq, i, err;
        u32 base, macen;

        if (port_num >= NUM_ETH_INTERFACES)
                return NULL;

        base  = CPHYSADDR(iflist[port_num].base_addr );
        macen = CPHYSADDR(iflist[port_num].macen_addr);
        irq = iflist[port_num].irq;

        if (!request_mem_region( base, MAC_IOSIZE, "Au1x00 ENET") ||
            !request_mem_region(macen, 4, "Au1x00 ENET"))
                return NULL;

        if (version_printed++ == 0)
                printk("%s version %s %s\n", DRV_NAME, DRV_VERSION, DRV_AUTHOR);

        dev = alloc_etherdev(sizeof(struct au1000_private));
        if (!dev) {
                printk(KERN_ERR "%s: alloc_etherdev failed\n", DRV_NAME);
                return NULL;
        }

        dev->base_addr = base;
        dev->irq = irq;
        dev->netdev_ops = &au1000_netdev_ops;
        SET_ETHTOOL_OPS(dev, &au1000_ethtool_ops);
        dev->watchdog_timeo = ETH_TX_TIMEOUT;

        err = register_netdev(dev);
        if (err != 0) {
                printk(KERN_ERR "%s: Cannot register net device, error %d\n",
                                DRV_NAME, err);
                free_netdev(dev);
                return NULL;
        }

        printk("%s: Au1xx0 Ethernet found at 0x%x, irq %d\n",
                dev->name, base, irq);

        aup = netdev_priv(dev);

        spin_lock_init(&aup->lock);

        /* Allocate the data buffers */
        /* Snooping works fine with eth on all au1xxx */
        aup->vaddr = (u32)dma_alloc_noncoherent(NULL, MAX_BUF_SIZE *
                                                (NUM_TX_BUFFS + NUM_RX_BUFFS),
                                                &aup->dma_addr, 0);
        if (!aup->vaddr) {
                free_netdev(dev);
                release_mem_region( base, MAC_IOSIZE);
                release_mem_region(macen, 4);
                return NULL;
        }

        /* aup->mac is the base address of the MAC's registers */
        aup->mac = (volatile mac_reg_t *)iflist[port_num].base_addr;

        /* Setup some variables for quick register address access */
        aup->enable = (volatile u32 *)iflist[port_num].macen_addr;
        aup->mac_id = port_num;
        au_macs[port_num] = aup;

        if (port_num == 0) {
                if (prom_get_ethernet_addr(ethaddr) == 0)
                        memcpy(au1000_mac_addr, ethaddr, sizeof(au1000_mac_addr));
                else {
                        printk(KERN_INFO "%s: No MAC address found\n",
                                         dev->name);
                                /* Use the hard coded MAC addresses */
                }

                setup_hw_rings(aup, MAC0_RX_DMA_ADDR, MAC0_TX_DMA_ADDR);
        } else if (port_num == 1)
                setup_hw_rings(aup, MAC1_RX_DMA_ADDR, MAC1_TX_DMA_ADDR);

        /*
         * Assign to the Ethernet ports two consecutive MAC addresses
         * to match those that are printed on their stickers
         */
        memcpy(dev->dev_addr, au1000_mac_addr, sizeof(au1000_mac_addr));
        dev->dev_addr[5] += port_num;

        *aup->enable = 0;
        aup->mac_enabled = 0;

        aup->mii_bus = mdiobus_alloc();
        if (aup->mii_bus == NULL)
                goto err_out;

        aup->mii_bus->priv = dev;
        aup->mii_bus->read = au1000_mdiobus_read;
        aup->mii_bus->write = au1000_mdiobus_write;
        aup->mii_bus->reset = au1000_mdiobus_reset;
        aup->mii_bus->name = "au1000_eth_mii";
        snprintf(aup->mii_bus->id, MII_BUS_ID_SIZE, "%x", aup->mac_id);
        aup->mii_bus->irq = kmalloc(sizeof(int)*PHY_MAX_ADDR, GFP_KERNEL);
        if (aup->mii_bus->irq == NULL)
                goto err_out;

        for(i = 0; i < PHY_MAX_ADDR; ++i)
                aup->mii_bus->irq[i] = PHY_POLL;

        /* if known, set corresponding PHY IRQs */
#if defined(AU1XXX_PHY_STATIC_CONFIG)
# if defined(AU1XXX_PHY0_IRQ)
        if (AU1XXX_PHY0_BUSID == aup->mac_id)
                aup->mii_bus->irq[AU1XXX_PHY0_ADDR] = AU1XXX_PHY0_IRQ;
# endif
# if defined(AU1XXX_PHY1_IRQ)
        if (AU1XXX_PHY1_BUSID == aup->mac_id)
                aup->mii_bus->irq[AU1XXX_PHY1_ADDR] = AU1XXX_PHY1_IRQ;
# endif
#endif
        mdiobus_register(aup->mii_bus);

        if (mii_probe(dev) != 0) {
                goto err_out;
        }

        pDBfree = NULL;
        /* setup the data buffer descriptors and attach a buffer to each one */
        pDB = aup->db;
        for (i = 0; i < (NUM_TX_BUFFS+NUM_RX_BUFFS); i++) {
                pDB->pnext = pDBfree;
                pDBfree = pDB;
                pDB->vaddr = (u32 *)((unsigned)aup->vaddr + MAX_BUF_SIZE*i);
                pDB->dma_addr = (dma_addr_t)virt_to_bus(pDB->vaddr);
                pDB++;
        }
        aup->pDBfree = pDBfree;

        for (i = 0; i < NUM_RX_DMA; i++) {
                pDB = GetFreeDB(aup);
                if (!pDB) {
                        goto err_out;
                }
                aup->rx_dma_ring[i]->buff_stat = (unsigned)pDB->dma_addr;
                aup->rx_db_inuse[i] = pDB;
        }
        for (i = 0; i < NUM_TX_DMA; i++) {
                pDB = GetFreeDB(aup);
                if (!pDB) {
                        goto err_out;
                }
                aup->tx_dma_ring[i]->buff_stat = (unsigned)pDB->dma_addr;
                aup->tx_dma_ring[i]->len = 0;
                aup->tx_db_inuse[i] = pDB;
        }

        /*
         * The boot code uses the ethernet controller, so reset it to start
         * fresh.  au1000_init() expects that the device is in reset state.
         */
        reset_mac(dev);

        return dev;

err_out:
        if (aup->mii_bus != NULL) {
                mdiobus_unregister(aup->mii_bus);
                mdiobus_free(aup->mii_bus);
        }

        /* here we should have a valid dev plus aup-> register addresses
         * so we can reset the mac properly.*/
        reset_mac(dev);

        for (i = 0; i < NUM_RX_DMA; i++) {
                if (aup->rx_db_inuse[i])
                        ReleaseDB(aup, aup->rx_db_inuse[i]);
        }
        for (i = 0; i < NUM_TX_DMA; i++) {
                if (aup->tx_db_inuse[i])
                        ReleaseDB(aup, aup->tx_db_inuse[i]);
        }
        dma_free_noncoherent(NULL, MAX_BUF_SIZE * (NUM_TX_BUFFS + NUM_RX_BUFFS),
                             (void *)aup->vaddr, aup->dma_addr);
        unregister_netdev(dev);
        free_netdev(dev);
        release_mem_region( base, MAC_IOSIZE);
        release_mem_region(macen, 4);
        return NULL;
}

/*
 * Setup the base address and interrupt of the Au1xxx ethernet macs
 * based on cpu type and whether the interface is enabled in sys_pinfunc
 * register. The last interface is enabled if SYS_PF_NI2 (bit 4) is 0.
 */
static int __init au1000_init_module(void)
{
        int ni = (int)((au_readl(SYS_PINFUNC) & (u32)(SYS_PF_NI2)) >> 4);
        struct net_device *dev;
        int i, found_one = 0;

        num_ifs = NUM_ETH_INTERFACES - ni;

        for(i = 0; i < num_ifs; i++) {
                dev = au1000_probe(i);
                iflist[i].dev = dev;
                if (dev)
                        found_one++;
        }
        if (!found_one)
                return -ENODEV;
        return 0;
}

static void __exit au1000_cleanup_module(void)
{
        int i, j;
        struct net_device *dev;
        struct au1000_private *aup;

        for (i = 0; i < num_ifs; i++) {
                dev = iflist[i].dev;
                if (dev) {
                        aup = netdev_priv(dev);
                        unregister_netdev(dev);
                        mdiobus_unregister(aup->mii_bus);
                        mdiobus_free(aup->mii_bus);
                        for (j = 0; j < NUM_RX_DMA; j++)
                                if (aup->rx_db_inuse[j])
                                        ReleaseDB(aup, aup->rx_db_inuse[j]);
                        for (j = 0; j < NUM_TX_DMA; j++)
                                if (aup->tx_db_inuse[j])
                                        ReleaseDB(aup, aup->tx_db_inuse[j]);
                        dma_free_noncoherent(NULL, MAX_BUF_SIZE *
                                             (NUM_TX_BUFFS + NUM_RX_BUFFS),
                                             (void *)aup->vaddr, aup->dma_addr);
                        release_mem_region(dev->base_addr, MAC_IOSIZE);
                        release_mem_region(CPHYSADDR(iflist[i].macen_addr), 4);
                        free_netdev(dev);
                }
        }
}

module_init(au1000_init_module);
module_exit(au1000_cleanup_module);