au1000_eth.c

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/*
 *
 * Alchemy Au1x00 ethernet driver
 *
 * Copyright 2001-2003, 2006 MontaVista Software Inc.
 * Copyright 2002 TimeSys Corp.
 * Added ethtool/mii-tool support,
 * Copyright 2004 Matt Porter <[email protected]>
 * Update: 2004 Bjoern Riemer, [email protected]
 * or [email protected]: fixed the link beat detection with
 * ioctls (SIOCGMIIPHY)
 * Copyright 2006 Herbert Valerio Riedel <[email protected]>
 *  converted to use linux-2.6.x's PHY framework
 *
 * Author: MontaVista Software, Inc.
 *      [email protected] or [email protected]
 *
 * ########################################################################
 *
 *  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.
 *
 * ########################################################################
 *
 *
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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 <linux/platform_device.h>
#include <linux/cpu.h>
#include <linux/io.h>

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

#include <au1000.h>
#include <au1xxx_eth.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 AU1000_DEF_MSG_ENABLE   (NETIF_MSG_DRV  | \
                NETIF_MSG_PROBE | \
                NETIF_MSG_LINK)

#define DRV_NAME    "au1000_eth"
#define DRV_VERSION "1.7"
#define DRV_AUTHOR  "Pete Popov <[email protected]>"
#define DRV_DESC    "Au1xxx on-chip Ethernet driver"

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

/*
 * 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.
 */

/*
 * board-specific configurations
 *
 * PHY detection algorithm
 *
 * If 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 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 phy1_search_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: phy1_search_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
 */

static void au1000_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)) {
        writel(MAC_EN_CLOCK_ENABLE, aup->enable);
        au_sync_delay(2);
        writel((MAC_EN_RESET0 | MAC_EN_RESET1 | MAC_EN_RESET2
                | MAC_EN_CLOCK_ENABLE), aup->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);
    u32 *const mii_control_reg = &aup->mac->mii_control;
    u32 *const mii_data_reg = &aup->mac->mii_data;
    u32 timedout = 20;
    u32 mii_control;

    while (readl(mii_control_reg) & MAC_MII_BUSY) {
        mdelay(1);
        if (--timedout == 0) {
            netdev_err(dev, "read_MII busy timeout!!\n");
            return -1;
        }
    }

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

    writel(mii_control, mii_control_reg);

    timedout = 20;
    while (readl(mii_control_reg) & MAC_MII_BUSY) {
        mdelay(1);
        if (--timedout == 0) {
            netdev_err(dev, "mdio_read busy timeout!!\n");
            return -1;
        }
    }
    return readl(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);
    u32 *const mii_control_reg = &aup->mac->mii_control;
    u32 *const mii_data_reg = &aup->mac->mii_data;
    u32 timedout = 20;
    u32 mii_control;

    while (readl(mii_control_reg) & MAC_MII_BUSY) {
        mdelay(1);
        if (--timedout == 0) {
            netdev_err(dev, "mdio_write busy timeout!!\n");
            return;
        }
    }

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

    writel(value, mii_data_reg);
    writel(mii_control, mii_control_reg);
}

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;

    /* make sure the MAC associated with this
     * mii_bus is enabled
     */
    au1000_enable_mac(dev, 0);

    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;

    /* make sure the MAC associated with this
     * mii_bus is enabled
     */
    au1000_enable_mac(dev, 0);

    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;

    /* make sure the MAC associated with this
     * mii_bus is enabled
     */
    au1000_enable_mac(dev, 0);

    return 0;
}

static void au1000_hard_stop(struct net_device *dev)
{
    struct au1000_private *aup = netdev_priv(dev);
    u32 reg;

    netif_dbg(aup, drv, dev, "hard stop\n");

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

static void au1000_enable_rx_tx(struct net_device *dev)
{
    struct au1000_private *aup = netdev_priv(dev);
    u32 reg;

    netif_dbg(aup, hw, dev, "enable_rx_tx\n");

    reg = readl(&aup->mac->control);
    reg |= (MAC_RX_ENABLE | MAC_TX_ENABLE);
    writel(reg, &aup->mac->control);
    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;
    u32 reg;

    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:
            netdev_warn(dev, "Speed (%d) is not 10/100 ???\n",
                            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! */
        au1000_hard_stop(dev);

        reg = readl(&aup->mac->control);
        if (DUPLEX_FULL == phydev->duplex) {
            reg |= MAC_FULL_DUPLEX;
            reg &= ~MAC_DISABLE_RX_OWN;
        } else {
            reg &= ~MAC_FULL_DUPLEX;
            reg |= MAC_DISABLE_RX_OWN;
        }
        writel(reg, &aup->mac->control);
        au_sync_delay(1);

        au1000_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)
            netdev_info(dev, "link up (%d/%s)\n",
                   phydev->speed,
                   DUPLEX_FULL == phydev->duplex ? "Full" : "Half");
        else
            netdev_info(dev, "link down\n");
    }
}

static int au1000_mii_probe(struct net_device *dev)
{
    struct au1000_private *const aup = netdev_priv(dev);
    struct phy_device *phydev = NULL;
    int phy_addr;

    if (aup->phy_static_config) {
        BUG_ON(aup->mac_id < 0 || aup->mac_id > 1);

        if (aup->phy_addr)
            phydev = aup->mii_bus->phy_map[aup->phy_addr];
        else
            netdev_info(dev, "using PHY-less setup\n");
        return 0;
    }

    /* 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 (!aup->phy_search_highest_addr)
                /* break out with first one found */
                break;
        }

    if (aup->phy1_search_mac0) {
        /* try harder to find a PHY */
        if (!phydev && (aup->mac_id == 1)) {
            /* no PHY found, maybe we have a dual PHY? */
            dev_info(&dev->dev, ": no PHY found on MAC1, "
                "let's see if it's attached to MAC0...\n");

            /* 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 =
                    aup->mii_bus->phy_map[phy_addr];

                if (aup->mac_id == 1)
                    break;

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

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

                phydev = tmp_phydev;
                break; /* found it */
            }
        }
    }

    if (!phydev) {
        netdev_err(dev, "no PHY found\n");
        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)) {
        netdev_err(dev, "Could not attach to PHY\n");
        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;

    netdev_info(dev, "attached PHY driver [%s] "
           "(mii_bus:phy_addr=%s, irq=%d)\n",
           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 struct db_dest *au1000_GetFreeDB(struct au1000_private *aup)
{
    struct db_dest *pDB;
    pDB = aup->pDBfree;

    if (pDB)
        aup->pDBfree = pDB->pnext;

    return pDB;
}

void au1000_ReleaseDB(struct au1000_private *aup, struct db_dest *pDB)
{
    struct db_dest *pDBfree = aup->pDBfree;
    if (pDBfree)
        pDBfree->pnext = pDB;
    aup->pDBfree = pDB;
}

static void au1000_reset_mac_unlocked(struct net_device *dev)
{
    struct au1000_private *const aup = netdev_priv(dev);
    int i;

    au1000_hard_stop(dev);

    writel(MAC_EN_CLOCK_ENABLE, aup->enable);
    au_sync_delay(2);
    writel(0, aup->enable);
    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 au1000_reset_mac(struct net_device *dev)
{
    struct au1000_private *const aup = netdev_priv(dev);
    unsigned long flags;

    netif_dbg(aup, hw, dev, "reset mac, aup %x\n",
                    (unsigned)aup);

    spin_lock_irqsave(&aup->lock, flags);

    au1000_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
au1000_setup_hw_rings(struct au1000_private *aup, void __iomem *tx_base)
{
    int i;

    for (i = 0; i < NUM_RX_DMA; i++) {
        aup->rx_dma_ring[i] = (struct rx_dma *)
            (tx_base + 0x100 + sizeof(struct rx_dma) * i);
    }
    for (i = 0; i < NUM_TX_DMA; i++) {
        aup->tx_dma_ring[i] = (struct tx_dma *)
            (tx_base + sizeof(struct tx_dma) * i);
    }
}

/*
 * 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 void au1000_set_msglevel(struct net_device *dev, u32 value)
{
    struct au1000_private *aup = netdev_priv(dev);
    aup->msg_enable = value;
}

static u32 au1000_get_msglevel(struct net_device *dev)
{
    struct au1000_private *aup = netdev_priv(dev);
    return aup->msg_enable;
}

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,
    .get_msglevel = au1000_get_msglevel,
    .set_msglevel = au1000_set_msglevel,
};


/*
 * 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;

    netif_dbg(aup, hw, dev, "au1000_init\n");

    /* bring the device out of reset */
    au1000_enable_mac(dev, 1);

    spin_lock_irqsave(&aup->lock, flags);

    writel(0, &aup->mac->control);
    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;

    writel(dev->dev_addr[5]<<8 | dev->dev_addr[4],
                    &aup->mac->mac_addr_high);
    writel(dev->dev_addr[3]<<24 | dev->dev_addr[2]<<16 |
        dev->dev_addr[1]<<8 | dev->dev_addr[0],
                    &aup->mac->mac_addr_low);


    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;
    }

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

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

static inline void au1000_update_rx_stats(struct net_device *dev, u32 status)
{
    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;
    struct rx_dma *prxd;
    u32 buff_stat, status;
    struct db_dest *pDB;
    u32 frmlen;

    netif_dbg(aup, rx_status, dev, "au1000_rx head %d\n", 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];
        au1000_update_rx_stats(dev, status);
        if (!(status & RX_ERROR))  {

            /* good frame */
            frmlen = (status & RX_FRAME_LEN_MASK);
            frmlen -= 4; /* Remove FCS */
            skb = netdev_alloc_skb(dev, frmlen + 2);
            if (skb == NULL) {
                netdev_err(dev, "Memory squeeze, dropping packet.\n");
                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) {
                pr_err("rx_error(s):");
                if (status & RX_MISSED_FRAME)
                    pr_cont(" miss");
                if (status & RX_WDOG_TIMER)
                    pr_cont(" wdog");
                if (status & RX_RUNT)
                    pr_cont(" runt");
                if (status & RX_OVERLEN)
                    pr_cont(" overlen");
                if (status & RX_COLL)
                    pr_cont(" coll");
                if (status & RX_MII_ERROR)
                    pr_cont(" mii error");
                if (status & RX_CRC_ERROR)
                    pr_cont(" crc error");
                if (status & RX_LEN_ERROR)
                    pr_cont(" len error");
                if (status & RX_U_CNTRL_FRAME)
                    pr_cont(" u control frame");
                pr_cont("\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 au1000_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);
    struct tx_dma *ptxd;

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

    while (ptxd->buff_stat & TX_T_DONE) {
        au1000_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);

    netif_dbg(aup, drv, dev, "open: dev=%p\n", dev);

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

    retval = au1000_init(dev);
    if (retval) {
        netdev_err(dev, "error in au1000_init\n");
        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);

    netif_dbg(aup, drv, dev, "open: Initialization done.\n");

    return 0;
}

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

    netif_dbg(aup, drv, dev, "close: dev=%p\n", dev);

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

    spin_lock_irqsave(&aup->lock, flags);

    au1000_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;
    struct tx_dma *ptxd;
    u32 buff_stat;
    struct db_dest *pDB;
    int i;

    netif_dbg(aup, tx_queued, dev, "tx: aup %x len=%d, data=%p, head %d\n",
                (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) {
        au1000_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, (void *)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);
    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)
{
    netdev_err(dev, "au1000_tx_timeout: dev=%p\n", dev);
    au1000_reset_mac(dev);
    au1000_init(dev);
    dev->trans_start = jiffies; /* prevent tx timeout */
    netif_wake_queue(dev);
}

static void au1000_multicast_list(struct net_device *dev)
{
    struct au1000_private *aup = netdev_priv(dev);
    u32 reg;

    netif_dbg(aup, drv, dev, "%s: flags=%x\n", __func__, dev->flags);
    reg = readl(&aup->mac->control);
    if (dev->flags & IFF_PROMISC) {         /* Set promiscuous. */
        reg |= MAC_PROMISCUOUS;
    } else if ((dev->flags & IFF_ALLMULTI)  ||
               netdev_mc_count(dev) > MULTICAST_FILTER_LIMIT) {
        reg |= MAC_PASS_ALL_MULTI;
        reg &= ~MAC_PROMISCUOUS;
        netdev_info(dev, "Pass all multicast\n");
    } else {
        struct netdev_hw_addr *ha;
        u32 mc_filter[2];   /* Multicast hash filter */

        mc_filter[1] = mc_filter[0] = 0;
        netdev_for_each_mc_addr(ha, dev)
            set_bit(ether_crc(ETH_ALEN, ha->addr)>>26,
                    (long *)mc_filter);
        writel(mc_filter[1], &aup->mac->multi_hash_high);
        writel(mc_filter[0], &aup->mac->multi_hash_low);
        reg &= ~MAC_PROMISCUOUS;
        reg |= MAC_HASH_MODE;
    }
    writel(reg, &aup->mac->control);
}

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, 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_rx_mode    = 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 int __devinit au1000_probe(struct platform_device *pdev)
{
    static unsigned version_printed;
    struct au1000_private *aup = NULL;
    struct au1000_eth_platform_data *pd;
    struct net_device *dev = NULL;
    struct db_dest *pDB, *pDBfree;
    int irq, i, err = 0;
    struct resource *base, *macen, *macdma;

    base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!base) {
        dev_err(&pdev->dev, "failed to retrieve base register\n");
        err = -ENODEV;
        goto out;
    }

    macen = platform_get_resource(pdev, IORESOURCE_MEM, 1);
    if (!macen) {
        dev_err(&pdev->dev, "failed to retrieve MAC Enable register\n");
        err = -ENODEV;
        goto out;
    }

    irq = platform_get_irq(pdev, 0);
    if (irq < 0) {
        dev_err(&pdev->dev, "failed to retrieve IRQ\n");
        err = -ENODEV;
        goto out;
    }

    macdma = platform_get_resource(pdev, IORESOURCE_MEM, 2);
    if (!macdma) {
        dev_err(&pdev->dev, "failed to retrieve MACDMA registers\n");
        err = -ENODEV;
        goto out;
    }

    if (!request_mem_region(base->start, resource_size(base),
                            pdev->name)) {
        dev_err(&pdev->dev, "failed to request memory region for base registers\n");
        err = -ENXIO;
        goto out;
    }

    if (!request_mem_region(macen->start, resource_size(macen),
                            pdev->name)) {
        dev_err(&pdev->dev, "failed to request memory region for MAC enable register\n");
        err = -ENXIO;
        goto err_request;
    }

    if (!request_mem_region(macdma->start, resource_size(macdma),
                            pdev->name)) {
        dev_err(&pdev->dev, "failed to request MACDMA memory region\n");
        err = -ENXIO;
        goto err_macdma;
    }

    dev = alloc_etherdev(sizeof(struct au1000_private));
    if (!dev) {
        err = -ENOMEM;
        goto err_alloc;
    }

    SET_NETDEV_DEV(dev, &pdev->dev);
    platform_set_drvdata(pdev, dev);
    aup = netdev_priv(dev);

    spin_lock_init(&aup->lock);
    aup->msg_enable = (au1000_debug < 4 ?
                AU1000_DEF_MSG_ENABLE : au1000_debug);

    /* 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) {
        dev_err(&pdev->dev, "failed to allocate data buffers\n");
        err = -ENOMEM;
        goto err_vaddr;
    }

    /* aup->mac is the base address of the MAC's registers */
    aup->mac = (struct mac_reg *)
            ioremap_nocache(base->start, resource_size(base));
    if (!aup->mac) {
        dev_err(&pdev->dev, "failed to ioremap MAC registers\n");
        err = -ENXIO;
        goto err_remap1;
    }

    /* Setup some variables for quick register address access */
    aup->enable = (u32 *)ioremap_nocache(macen->start,
                        resource_size(macen));
    if (!aup->enable) {
        dev_err(&pdev->dev, "failed to ioremap MAC enable register\n");
        err = -ENXIO;
        goto err_remap2;
    }
    aup->mac_id = pdev->id;

    aup->macdma = ioremap_nocache(macdma->start, resource_size(macdma));
    if (!aup->macdma) {
        dev_err(&pdev->dev, "failed to ioremap MACDMA registers\n");
        err = -ENXIO;
        goto err_remap3;
    }

    au1000_setup_hw_rings(aup, aup->macdma);

    writel(0, aup->enable);
    aup->mac_enabled = 0;

    pd = pdev->dev.platform_data;
    if (!pd) {
        dev_info(&pdev->dev, "no platform_data passed,"
                    " PHY search on MAC0\n");
        aup->phy1_search_mac0 = 1;
    } else {
        if (is_valid_ether_addr(pd->mac)) {
            memcpy(dev->dev_addr, pd->mac, 6);
        } else {
            /* Set a random MAC since no valid provided by platform_data. */
            eth_hw_addr_random(dev);
        }

        aup->phy_static_config = pd->phy_static_config;
        aup->phy_search_highest_addr = pd->phy_search_highest_addr;
        aup->phy1_search_mac0 = pd->phy1_search_mac0;
        aup->phy_addr = pd->phy_addr;
        aup->phy_busid = pd->phy_busid;
        aup->phy_irq = pd->phy_irq;
    }

    if (aup->phy_busid && aup->phy_busid > 0) {
        dev_err(&pdev->dev, "MAC0-associated PHY attached 2nd MACs MII bus not supported yet\n");
        err = -ENODEV;
        goto err_mdiobus_alloc;
    }

    aup->mii_bus = mdiobus_alloc();
    if (aup->mii_bus == NULL) {
        dev_err(&pdev->dev, "failed to allocate mdiobus structure\n");
        err = -ENOMEM;
        goto err_mdiobus_alloc;
    }

    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, "%s-%x",
        pdev->name, aup->mac_id);
    aup->mii_bus->irq = kmalloc(sizeof(int)*PHY_MAX_ADDR, GFP_KERNEL);
    if (aup->mii_bus->irq == NULL) {
        err = -ENOMEM;
        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 (aup->phy_static_config)
        if (aup->phy_irq && aup->phy_busid == aup->mac_id)
            aup->mii_bus->irq[aup->phy_addr] = aup->phy_irq;

    err = mdiobus_register(aup->mii_bus);
    if (err) {
        dev_err(&pdev->dev, "failed to register MDIO bus\n");
        goto err_mdiobus_reg;
    }

    err = au1000_mii_probe(dev);
    if (err != 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;

    err = -ENODEV;
    for (i = 0; i < NUM_RX_DMA; i++) {
        pDB = au1000_GetFreeDB(aup);
        if (!pDB)
            goto err_out;

        aup->rx_dma_ring[i]->buff_stat = (unsigned)pDB->dma_addr;
        aup->rx_db_inuse[i] = pDB;
    }

    err = -ENODEV;
    for (i = 0; i < NUM_TX_DMA; i++) {
        pDB = au1000_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;
    }

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

    /*
     * The boot code uses the ethernet controller, so reset it to start
     * fresh.  au1000_init() expects that the device is in reset state.
     */
    au1000_reset_mac(dev);

    err = register_netdev(dev);
    if (err) {
        netdev_err(dev, "Cannot register net device, aborting.\n");
        goto err_out;
    }

    netdev_info(dev, "Au1xx0 Ethernet found at 0x%lx, irq %d\n",
            (unsigned long)base->start, irq);
    if (version_printed++ == 0)
        pr_info("%s version %s %s\n",
                    DRV_NAME, DRV_VERSION, DRV_AUTHOR);

    return 0;

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

    /* here we should have a valid dev plus aup-> register addresses
     * so we can reset the mac properly.
     */
    au1000_reset_mac(dev);

    for (i = 0; i < NUM_RX_DMA; i++) {
        if (aup->rx_db_inuse[i])
            au1000_ReleaseDB(aup, aup->rx_db_inuse[i]);
    }
    for (i = 0; i < NUM_TX_DMA; i++) {
        if (aup->tx_db_inuse[i])
            au1000_ReleaseDB(aup, aup->tx_db_inuse[i]);
    }
err_mdiobus_reg:
    mdiobus_free(aup->mii_bus);
err_mdiobus_alloc:
    iounmap(aup->macdma);
err_remap3:
    iounmap(aup->enable);
err_remap2:
    iounmap(aup->mac);
err_remap1:
    dma_free_noncoherent(NULL, MAX_BUF_SIZE * (NUM_TX_BUFFS + NUM_RX_BUFFS),
                 (void *)aup->vaddr, aup->dma_addr);
err_vaddr:
    free_netdev(dev);
err_alloc:
    release_mem_region(macdma->start, resource_size(macdma));
err_macdma:
    release_mem_region(macen->start, resource_size(macen));
err_request:
    release_mem_region(base->start, resource_size(base));
out:
    return err;
}

static int __devexit au1000_remove(struct platform_device *pdev)
{
    struct net_device *dev = platform_get_drvdata(pdev);
    struct au1000_private *aup = netdev_priv(dev);
    int i;
    struct resource *base, *macen;

    platform_set_drvdata(pdev, NULL);

    unregister_netdev(dev);
    mdiobus_unregister(aup->mii_bus);
    mdiobus_free(aup->mii_bus);

    for (i = 0; i < NUM_RX_DMA; i++)
        if (aup->rx_db_inuse[i])
            au1000_ReleaseDB(aup, aup->rx_db_inuse[i]);

    for (i = 0; i < NUM_TX_DMA; i++)
        if (aup->tx_db_inuse[i])
            au1000_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);

    iounmap(aup->macdma);
    iounmap(aup->mac);
    iounmap(aup->enable);

    base = platform_get_resource(pdev, IORESOURCE_MEM, 2);
    release_mem_region(base->start, resource_size(base));

    base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    release_mem_region(base->start, resource_size(base));

    macen = platform_get_resource(pdev, IORESOURCE_MEM, 1);
    release_mem_region(macen->start, resource_size(macen));

    free_netdev(dev);

    return 0;
}

static struct platform_driver au1000_eth_driver = {
    .probe  = au1000_probe,
    .remove = __devexit_p(au1000_remove),
    .driver = {
        .name   = "au1000-eth",
        .owner  = THIS_MODULE,
    },
};

module_platform_driver(au1000_eth_driver);

MODULE_ALIAS("platform:au1000-eth");