/*
 * Fast Ethernet Controller (FEC) driver for Motorola MPC8xx.
 *
 * Copyright (c) 2003 Intracom S.A. 
 *  by Pantelis Antoniou <panto@intracom.gr>
 *
 * Heavily based on original FEC driver by Dan Malek <dan@embeddededge.com>
 * and modifications by Joakim Tjernlund <joakim.tjernlund@lumentis.se>
 *
 * Released under the GPL
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/bitops.h>
#include <linux/dma-mapping.h>

#include <asm/8xx_immap.h>
#include <asm/pgtable.h>
#include <asm/mpc8xx.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/commproc.h>

#include "fec_8xx.h"

/*************************************************/

#define FEC_MAX_MULTICAST_ADDRS 64

/*************************************************/

static char version[] __devinitdata =
    DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")" "\n";

MODULE_AUTHOR("Pantelis Antoniou <panto@intracom.gr>");
MODULE_DESCRIPTION("Motorola 8xx FEC ethernet driver");
MODULE_LICENSE("GPL");

int fec_8xx_debug = -1;         /* -1 == use FEC_8XX_DEF_MSG_ENABLE as value */
module_param(fec_8xx_debug, int, 0);
MODULE_PARM_DESC(fec_8xx_debug,
                 "FEC 8xx bitmapped debugging message enable value");


/*************************************************/

/*
 * Delay to wait for FEC reset command to complete (in us) 
 */
#define FEC_RESET_DELAY         50

/*****************************************************************************************/

static void fec_whack_reset(fec_t * fecp)
{
        int i;

        /*
         * Whack a reset.  We should wait for this.  
         */
        FW(fecp, ecntrl, FEC_ECNTRL_PINMUX | FEC_ECNTRL_RESET);
        for (i = 0;
             (FR(fecp, ecntrl) & FEC_ECNTRL_RESET) != 0 && i < FEC_RESET_DELAY;
             i++)
                udelay(1);

        if (i == FEC_RESET_DELAY)
                printk(KERN_WARNING "FEC Reset timeout!\n");

}

/****************************************************************************/

/*
 * Transmitter timeout.  
 */
#define TX_TIMEOUT (2*HZ)

/****************************************************************************/

/*
 * Returns the CRC needed when filling in the hash table for
 * multicast group filtering
 * pAddr must point to a MAC address (6 bytes)
 */
static __u32 fec_mulicast_calc_crc(char *pAddr)
{
        u8 byte;
        int byte_count;
        int bit_count;
        __u32 crc = 0xffffffff;
        u8 msb;

        for (byte_count = 0; byte_count < 6; byte_count++) {
                byte = pAddr[byte_count];
                for (bit_count = 0; bit_count < 8; bit_count++) {
                        msb = crc >> 31;
                        crc <<= 1;
                        if (msb ^ (byte & 0x1)) {
                                crc ^= FEC_CRC_POLY;
                        }
                        byte >>= 1;
                }
        }
        return (crc);
}

/*
 * Set or clear the multicast filter for this adaptor.
 * Skeleton taken from sunlance driver.
 * The CPM Ethernet implementation allows Multicast as well as individual
 * MAC address filtering.  Some of the drivers check to make sure it is
 * a group multicast address, and discard those that are not.  I guess I
 * will do the same for now, but just remove the test if you want
 * individual filtering as well (do the upper net layers want or support
 * this kind of feature?).
 */
static void fec_set_multicast_list(struct net_device *dev)
{
        struct fec_enet_private *fep = netdev_priv(dev);
        fec_t *fecp = fep->fecp;
        struct dev_mc_list *pmc;
        __u32 crc;
        int temp;
        __u32 csrVal;
        int hash_index;
        __u32 hthi, htlo;
        unsigned long flags;


        if ((dev->flags & IFF_PROMISC) != 0) {

                spin_lock_irqsave(&fep->lock, flags);
                FS(fecp, r_cntrl, FEC_RCNTRL_PROM);
                spin_unlock_irqrestore(&fep->lock, flags);

                /*
                 * Log any net taps. 
                 */
                printk(KERN_WARNING DRV_MODULE_NAME
                       ": %s: Promiscuous mode enabled.\n", dev->name);
                return;

        }

        if ((dev->flags & IFF_ALLMULTI) != 0 ||
            dev->mc_count > FEC_MAX_MULTICAST_ADDRS) {
                /*
                 * Catch all multicast addresses, set the filter to all 1's.
                 */
                hthi = 0xffffffffU;
                htlo = 0xffffffffU;
        } else {
                hthi = 0;
                htlo = 0;

                /*
                 * Now populate the hash table 
                 */
                for (pmc = dev->mc_list; pmc != NULL; pmc = pmc->next) {
                        crc = fec_mulicast_calc_crc(pmc->dmi_addr);
                        temp = (crc & 0x3f) >> 1;
                        hash_index = ((temp & 0x01) << 4) |
                                     ((temp & 0x02) << 2) |
                                     ((temp & 0x04)) |
                                     ((temp & 0x08) >> 2) |
                                     ((temp & 0x10) >> 4);
                        csrVal = (1 << hash_index);
                        if (crc & 1)
                                hthi |= csrVal;
                        else
                                htlo |= csrVal;
                }
        }

        spin_lock_irqsave(&fep->lock, flags);
        FC(fecp, r_cntrl, FEC_RCNTRL_PROM);
        FW(fecp, hash_table_high, hthi);
        FW(fecp, hash_table_low, htlo);
        spin_unlock_irqrestore(&fep->lock, flags);
}

static int fec_set_mac_address(struct net_device *dev, void *addr)
{
        struct sockaddr *mac = addr;
        struct fec_enet_private *fep = netdev_priv(dev);
        struct fec *fecp = fep->fecp;
        int i;
        __u32 addrhi, addrlo;
        unsigned long flags;

        /* Get pointer to SCC area in parameter RAM. */
        for (i = 0; i < 6; i++)
                dev->dev_addr[i] = mac->sa_data[i];

        /*
         * Set station address. 
         */
        addrhi = ((__u32) dev->dev_addr[0] << 24) |
                 ((__u32) dev->dev_addr[1] << 16) |
                 ((__u32) dev->dev_addr[2] <<  8) |
                  (__u32) dev->dev_addr[3];
        addrlo = ((__u32) dev->dev_addr[4] << 24) |
                 ((__u32) dev->dev_addr[5] << 16);

        spin_lock_irqsave(&fep->lock, flags);
        FW(fecp, addr_low, addrhi);
        FW(fecp, addr_high, addrlo);
        spin_unlock_irqrestore(&fep->lock, flags);

        return 0;
}

/*
 * This function is called to start or restart the FEC during a link
 * change.  This only happens when switching between half and full
 * duplex.
 */
void fec_restart(struct net_device *dev, int duplex, int speed)
{
#ifdef CONFIG_DUET
        immap_t *immap = (immap_t *) IMAP_ADDR;
        __u32 cptr;
#endif
        struct fec_enet_private *fep = netdev_priv(dev);
        struct fec *fecp = fep->fecp;
        const struct fec_platform_info *fpi = fep->fpi;
        cbd_t *bdp;
        struct sk_buff *skb;
        int i;
        __u32 addrhi, addrlo;

        fec_whack_reset(fep->fecp);

        /*
         * Set station address. 
         */
        addrhi = ((__u32) dev->dev_addr[0] << 24) |
                 ((__u32) dev->dev_addr[1] << 16) |
                 ((__u32) dev->dev_addr[2] <<  8) |
                 (__u32) dev->dev_addr[3];
        addrlo = ((__u32) dev->dev_addr[4] << 24) |
                 ((__u32) dev->dev_addr[5] << 16);
        FW(fecp, addr_low, addrhi);
        FW(fecp, addr_high, addrlo);

        /*
         * Reset all multicast. 
         */
        FW(fecp, hash_table_high, 0);
        FW(fecp, hash_table_low, 0);

        /*
         * Set maximum receive buffer size. 
         */
        FW(fecp, r_buff_size, PKT_MAXBLR_SIZE);
        FW(fecp, r_hash, PKT_MAXBUF_SIZE);

        /*
         * Set receive and transmit descriptor base. 
         */
        FW(fecp, r_des_start, iopa((__u32) (fep->rx_bd_base)));
        FW(fecp, x_des_start, iopa((__u32) (fep->tx_bd_base)));

        fep->dirty_tx = fep->cur_tx = fep->tx_bd_base;
        fep->tx_free = fep->tx_ring;
        fep->cur_rx = fep->rx_bd_base;

        /*
         * Reset SKB receive buffers 
         */
        for (i = 0; i < fep->rx_ring; i++) {
                if ((skb = fep->rx_skbuff[i]) == NULL)
                        continue;
                fep->rx_skbuff[i] = NULL;
                dev_kfree_skb(skb);
        }

        /*
         * Initialize the receive buffer descriptors. 
         */
        for (i = 0, bdp = fep->rx_bd_base; i < fep->rx_ring; i++, bdp++) {
                skb = dev_alloc_skb(ENET_RX_FRSIZE);
                if (skb == NULL) {
                        printk(KERN_WARNING DRV_MODULE_NAME
                               ": %s Memory squeeze, unable to allocate skb\n",
                               dev->name);
                        fep->stats.rx_dropped++;
                        break;
                }
                fep->rx_skbuff[i] = skb;
                skb->dev = dev;
                CBDW_BUFADDR(bdp, dma_map_single(NULL, skb->data,
                                         L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
                                         DMA_FROM_DEVICE));
                CBDW_DATLEN(bdp, 0);    /* zero */
                CBDW_SC(bdp, BD_ENET_RX_EMPTY |
                        ((i < fep->rx_ring - 1) ? 0 : BD_SC_WRAP));
        }
        /*
         * if we failed, fillup remainder 
         */
        for (; i < fep->rx_ring; i++, bdp++) {
                fep->rx_skbuff[i] = NULL;
                CBDW_SC(bdp, (i < fep->rx_ring - 1) ? 0 : BD_SC_WRAP);
        }

        /*
         * Reset SKB transmit buffers.  
         */
        for (i = 0; i < fep->tx_ring; i++) {
                if ((skb = fep->tx_skbuff[i]) == NULL)
                        continue;
                fep->tx_skbuff[i] = NULL;
                dev_kfree_skb(skb);
        }

        /*
         * ...and the same for transmit.  
         */
        for (i = 0, bdp = fep->tx_bd_base; i < fep->tx_ring; i++, bdp++) {
                fep->tx_skbuff[i] = NULL;
                CBDW_BUFADDR(bdp, virt_to_bus(NULL));
                CBDW_DATLEN(bdp, 0);
                CBDW_SC(bdp, (i < fep->tx_ring - 1) ? 0 : BD_SC_WRAP);
        }

        /*
         * Enable big endian and don't care about SDMA FC. 
         */
        FW(fecp, fun_code, 0x78000000);

        /*
         * Set MII speed. 
         */
        FW(fecp, mii_speed, fep->fec_phy_speed);

        /*
         * Clear any outstanding interrupt. 
         */
        FW(fecp, ievent, 0xffc0);
        FW(fecp, ivec, (fpi->fec_irq / 2) << 29);

        /*
         * adjust to speed (only for DUET & RMII) 
         */
#ifdef CONFIG_DUET
        cptr = in_be32(&immap->im_cpm.cp_cptr);
        switch (fpi->fec_no) {
        case 0:
                /*
                 * check if in RMII mode 
                 */
                if ((cptr & 0x100) == 0)
                        break;

                if (speed == 10)
                        cptr |= 0x0000010;
                else if (speed == 100)
                        cptr &= ~0x0000010;
                break;
        case 1:
                /*
                 * check if in RMII mode 
                 */
                if ((cptr & 0x80) == 0)
                        break;

                if (speed == 10)
                        cptr |= 0x0000008;
                else if (speed == 100)
                        cptr &= ~0x0000008;
                break;
        default:
                break;
        }
        out_be32(&immap->im_cpm.cp_cptr, cptr);
#endif

        FW(fecp, r_cntrl, FEC_RCNTRL_MII_MODE); /* MII enable */
        /*
         * adjust to duplex mode 
         */
        if (duplex) {
                FC(fecp, r_cntrl, FEC_RCNTRL_DRT);
                FS(fecp, x_cntrl, FEC_TCNTRL_FDEN);     /* FD enable */
        } else {
                FS(fecp, r_cntrl, FEC_RCNTRL_DRT);
                FC(fecp, x_cntrl, FEC_TCNTRL_FDEN);     /* FD disable */
        }

        /*
         * Enable interrupts we wish to service. 
         */
        FW(fecp, imask, FEC_ENET_TXF | FEC_ENET_TXB |
           FEC_ENET_RXF | FEC_ENET_RXB);

        /*
         * And last, enable the transmit and receive processing. 
         */
        FW(fecp, ecntrl, FEC_ECNTRL_PINMUX | FEC_ECNTRL_ETHER_EN);
        FW(fecp, r_des_active, 0x01000000);
}

void fec_stop(struct net_device *dev)
{
        struct fec_enet_private *fep = netdev_priv(dev);
        fec_t *fecp = fep->fecp;
        struct sk_buff *skb;
        int i;

        if ((FR(fecp, ecntrl) & FEC_ECNTRL_ETHER_EN) == 0)
                return;         /* already down */

        FW(fecp, x_cntrl, 0x01);        /* Graceful transmit stop */
        for (i = 0; ((FR(fecp, ievent) & 0x10000000) == 0) &&
             i < FEC_RESET_DELAY; i++)
                udelay(1);

        if (i == FEC_RESET_DELAY)
                printk(KERN_WARNING DRV_MODULE_NAME
                       ": %s FEC timeout on graceful transmit stop\n",
                       dev->name);
        /*
         * Disable FEC. Let only MII interrupts. 
         */
        FW(fecp, imask, 0);
        FW(fecp, ecntrl, ~FEC_ECNTRL_ETHER_EN);

        /*
         * Reset SKB transmit buffers.  
         */
        for (i = 0; i < fep->tx_ring; i++) {
                if ((skb = fep->tx_skbuff[i]) == NULL)
                        continue;
                fep->tx_skbuff[i] = NULL;
                dev_kfree_skb(skb);
        }

        /*
         * Reset SKB receive buffers 
         */
        for (i = 0; i < fep->rx_ring; i++) {
                if ((skb = fep->rx_skbuff[i]) == NULL)
                        continue;
                fep->rx_skbuff[i] = NULL;
                dev_kfree_skb(skb);
        }
}

/* common receive function */
static int fec_enet_rx_common(struct fec_enet_private *ep,
                              struct net_device *dev, int budget)
{
        fec_t *fecp = fep->fecp;
        const struct fec_platform_info *fpi = fep->fpi;
        cbd_t *bdp;
        struct sk_buff *skb, *skbn, *skbt;
        int received = 0;
        __u16 pkt_len, sc;
        int curidx;

        /*
         * First, grab all of the stats for the incoming packet.
         * These get messed up if we get called due to a busy condition.
         */
        bdp = fep->cur_rx;

        /* clear RX status bits for napi*/
        if (fpi->use_napi)
                FW(fecp, ievent, FEC_ENET_RXF | FEC_ENET_RXB);

        while (((sc = CBDR_SC(bdp)) & BD_ENET_RX_EMPTY) == 0) {

                curidx = bdp - fep->rx_bd_base;

                /*
                 * Since we have allocated space to hold a complete frame,
                 * the last indicator should be set.
                 */
                if ((sc & BD_ENET_RX_LAST) == 0)
                        printk(KERN_WARNING DRV_MODULE_NAME
                               ": %s rcv is not +last\n",
                               dev->name);

                /*
                 * Check for errors. 
                 */
                if (sc & (BD_ENET_RX_LG | BD_ENET_RX_SH | BD_ENET_RX_CL |
                          BD_ENET_RX_NO | BD_ENET_RX_CR | BD_ENET_RX_OV)) {
                        fep->stats.rx_errors++;
                        /* Frame too long or too short. */
                        if (sc & (BD_ENET_RX_LG | BD_ENET_RX_SH))
                                fep->stats.rx_length_errors++;
                        /* Frame alignment */
                        if (sc & (BD_ENET_RX_NO | BD_ENET_RX_CL))
                                fep->stats.rx_frame_errors++;
                        /* CRC Error */
                        if (sc & BD_ENET_RX_CR)
                                fep->stats.rx_crc_errors++;
                        /* FIFO overrun */
                        if (sc & BD_ENET_RX_OV)
                                fep->stats.rx_crc_errors++;

                        skbn = fep->rx_skbuff[curidx];
                        BUG_ON(skbn == NULL);

                } else {
                        skb = fep->rx_skbuff[curidx];
                        BUG_ON(skb == NULL);

                        /*
                         * Process the incoming frame.
                         */
                        fep->stats.rx_packets++;
                        pkt_len = CBDR_DATLEN(bdp) - 4; /* remove CRC */
                        fep->stats.rx_bytes += pkt_len + 4;

                        if (pkt_len <= fpi->rx_copybreak) {
                                /* +2 to make IP header L1 cache aligned */
                                skbn = dev_alloc_skb(pkt_len + 2);
                                if (skbn != NULL) {
                                        skb_reserve(skbn, 2);   /* align IP header */
                                        skb_copy_from_linear_data(skb,
                                                                  skbn->data,
                                                                  pkt_len);
                                        /* swap */
                                        skbt = skb;
                                        skb = skbn;
                                        skbn = skbt;
                                }
                        } else
                                skbn = dev_alloc_skb(ENET_RX_FRSIZE);

                        if (skbn != NULL) {
                                skb_put(skb, pkt_len);  /* Make room */
                                skb->protocol = eth_type_trans(skb, dev);
                                received++;
                                if (!fpi->use_napi)
                                        netif_rx(skb);
                                else
                                        netif_receive_skb(skb);
                        } else {
                                printk(KERN_WARNING DRV_MODULE_NAME
                                       ": %s Memory squeeze, dropping packet.\n",
                                       dev->name);
                                fep->stats.rx_dropped++;
                                skbn = skb;
                        }
                }

                fep->rx_skbuff[curidx] = skbn;
                CBDW_BUFADDR(bdp, dma_map_single(NULL, skbn->data,
                                                 L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
                                                 DMA_FROM_DEVICE));
                CBDW_DATLEN(bdp, 0);
                CBDW_SC(bdp, (sc & ~BD_ENET_RX_STATS) | BD_ENET_RX_EMPTY);

                /*
                 * Update BD pointer to next entry. 
                 */
                if ((sc & BD_ENET_RX_WRAP) == 0)
                        bdp++;
                else
                        bdp = fep->rx_bd_base;

                /*
                 * Doing this here will keep the FEC running while we process
                 * incoming frames.  On a heavily loaded network, we should be
                 * able to keep up at the expense of system resources.
                 */
                FW(fecp, r_des_active, 0x01000000);

                if (received >= budget)
                        break;

        }

        fep->cur_rx = bdp;

        if (fpi->use_napi) {
                if (received < budget) {
                        netif_rx_complete(dev, &fep->napi);

                        /* enable RX interrupt bits */
                        FS(fecp, imask, FEC_ENET_RXF | FEC_ENET_RXB);
                }
        }

        return received;
}

static void fec_enet_tx(struct net_device *dev)
{
        struct fec_enet_private *fep = netdev_priv(dev);
        cbd_t *bdp;
        struct sk_buff *skb;
        int dirtyidx, do_wake;
        __u16 sc;

        spin_lock(&fep->lock);
        bdp = fep->dirty_tx;

        do_wake = 0;
        while (((sc = CBDR_SC(bdp)) & BD_ENET_TX_READY) == 0) {

                dirtyidx = bdp - fep->tx_bd_base;

                if (fep->tx_free == fep->tx_ring)
                        break;

                skb = fep->tx_skbuff[dirtyidx];

                /*
                 * Check for errors. 
                 */
                if (sc & (BD_ENET_TX_HB | BD_ENET_TX_LC |
                          BD_ENET_TX_RL | BD_ENET_TX_UN | BD_ENET_TX_CSL)) {
                        fep->stats.tx_errors++;
                        if (sc & BD_ENET_TX_HB) /* No heartbeat */
                                fep->stats.tx_heartbeat_errors++;
                        if (sc & BD_ENET_TX_LC) /* Late collision */
                                fep->stats.tx_window_errors++;
                        if (sc & BD_ENET_TX_RL) /* Retrans limit */
                                fep->stats.tx_aborted_errors++;
                        if (sc & BD_ENET_TX_UN) /* Underrun */
                                fep->stats.tx_fifo_errors++;
                        if (sc & BD_ENET_TX_CSL)        /* Carrier lost */
                                fep->stats.tx_carrier_errors++;
                } else
                        fep->stats.tx_packets++;

                if (sc & BD_ENET_TX_READY)
                        printk(KERN_WARNING DRV_MODULE_NAME
                               ": %s HEY! Enet xmit interrupt and TX_READY.\n",
                               dev->name);

                /*
                 * Deferred means some collisions occurred during transmit,
                 * but we eventually sent the packet OK.
                 */
                if (sc & BD_ENET_TX_DEF)
                        fep->stats.collisions++;

                /*
                 * Free the sk buffer associated with this last transmit. 
                 */
                dev_kfree_skb_irq(skb);
                fep->tx_skbuff[dirtyidx] = NULL;

                /*
                 * Update pointer to next buffer descriptor to be transmitted. 
                 */
                if ((sc & BD_ENET_TX_WRAP) == 0)
                        bdp++;
                else
                        bdp = fep->tx_bd_base;

                /*
                 * Since we have freed up a buffer, the ring is no longer
                 * full.
                 */
                if (!fep->tx_free++)
                        do_wake = 1;
        }

        fep->dirty_tx = bdp;

        spin_unlock(&fep->lock);

        if (do_wake && netif_queue_stopped(dev))
                netif_wake_queue(dev);
}

/*
 * The interrupt handler.
 * This is called from the MPC core interrupt.
 */
static irqreturn_t
fec_enet_interrupt(int irq, void *dev_id)
{
        struct net_device *dev = dev_id;
        struct fec_enet_private *fep;
        const struct fec_platform_info *fpi;
        fec_t *fecp;
        __u32 int_events;
        __u32 int_events_napi;

        if (unlikely(dev == NULL))
                return IRQ_NONE;

        fep = netdev_priv(dev);
        fecp = fep->fecp;
        fpi = fep->fpi;

        /*
         * Get the interrupt events that caused us to be here.
         */
        while ((int_events = FR(fecp, ievent) & FR(fecp, imask)) != 0) {

                if (!fpi->use_napi)
                        FW(fecp, ievent, int_events);
                else {
                        int_events_napi = int_events & ~(FEC_ENET_RXF | FEC_ENET_RXB);
                        FW(fecp, ievent, int_events_napi);
                }

                if ((int_events & (FEC_ENET_HBERR | FEC_ENET_BABR |
                                   FEC_ENET_BABT | FEC_ENET_EBERR)) != 0)
                        printk(KERN_WARNING DRV_MODULE_NAME
                               ": %s FEC ERROR(s) 0x%x\n",
                               dev->name, int_events);

                if ((int_events & FEC_ENET_RXF) != 0) {
                        if (!fpi->use_napi)
                                fec_enet_rx_common(fep, dev, ~0);
                        else {
                                if (netif_rx_schedule_prep(dev, &fep->napi)) {
                                        /* disable rx interrupts */
                                        FC(fecp, imask, FEC_ENET_RXF | FEC_ENET_RXB);
                                        __netif_rx_schedule(dev, &fep->napi);
                                } else {
                                        printk(KERN_ERR DRV_MODULE_NAME
                                               ": %s driver bug! interrupt while in poll!\n",
                                               dev->name);
                                        FC(fecp, imask, FEC_ENET_RXF | FEC_ENET_RXB);
                                }
                        }
                }

                if ((int_events & FEC_ENET_TXF) != 0)
                        fec_enet_tx(dev);
        }

        return IRQ_HANDLED;
}

/* This interrupt occurs when the PHY detects a link change. */
static irqreturn_t
fec_mii_link_interrupt(int irq, void *dev_id)
{
        struct net_device *dev = dev_id;
        struct fec_enet_private *fep;
        const struct fec_platform_info *fpi;

        if (unlikely(dev == NULL))
                return IRQ_NONE;

        fep = netdev_priv(dev);
        fpi = fep->fpi;

        if (!fpi->use_mdio)
                return IRQ_NONE;

        /*
         * Acknowledge the interrupt if possible. If we have not
         * found the PHY yet we can't process or acknowledge the
         * interrupt now. Instead we ignore this interrupt for now,
         * which we can do since it is edge triggered. It will be
         * acknowledged later by fec_enet_open().
         */
        if (!fep->phy)
                return IRQ_NONE;

        fec_mii_ack_int(dev);
        fec_mii_link_status_change_check(dev, 0);

        return IRQ_HANDLED;
}


/**********************************************************************************/

static int fec_enet_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct fec_enet_private *fep = netdev_priv(dev);
        fec_t *fecp = fep->fecp;
        cbd_t *bdp;
        int curidx;
        unsigned long flags;

        spin_lock_irqsave(&fep->tx_lock, flags);

        /*
         * Fill in a Tx ring entry 
         */
        bdp = fep->cur_tx;

        if (!fep->tx_free || (CBDR_SC(bdp) & BD_ENET_TX_READY)) {
                netif_stop_queue(dev);
                spin_unlock_irqrestore(&fep->tx_lock, flags);

                /*
                 * Ooops.  All transmit buffers are full.  Bail out.
                 * This should not happen, since the tx queue should be stopped.
                 */
                printk(KERN_WARNING DRV_MODULE_NAME
                       ": %s tx queue full!.\n", dev->name);
                return 1;
        }

        curidx = bdp - fep->tx_bd_base;
        /*
         * Clear all of the status flags. 
         */
        CBDC_SC(bdp, BD_ENET_TX_STATS);

        /*
         * Save skb pointer. 
         */
        fep->tx_skbuff[curidx] = skb;

        fep->stats.tx_bytes += skb->len;

        /*
         * Push the data cache so the CPM does not get stale memory data. 
         */
        CBDW_BUFADDR(bdp, dma_map_single(NULL, skb->data,
                                         skb->len, DMA_TO_DEVICE));
        CBDW_DATLEN(bdp, skb->len);

        dev->trans_start = jiffies;

        /*
         * If this was the last BD in the ring, start at the beginning again. 
         */
        if ((CBDR_SC(bdp) & BD_ENET_TX_WRAP) == 0)
                fep->cur_tx++;
        else
                fep->cur_tx = fep->tx_bd_base;

        if (!--fep->tx_free)
                netif_stop_queue(dev);

        /*
         * Trigger transmission start 
         */
        CBDS_SC(bdp, BD_ENET_TX_READY | BD_ENET_TX_INTR |
                BD_ENET_TX_LAST | BD_ENET_TX_TC);
        FW(fecp, x_des_active, 0x01000000);

        spin_unlock_irqrestore(&fep->tx_lock, flags);

        return 0;
}

static void fec_timeout(struct net_device *dev)
{
        struct fec_enet_private *fep = netdev_priv(dev);

        fep->stats.tx_errors++;

        if (fep->tx_free)
                netif_wake_queue(dev);

        /* check link status again */
        fec_mii_link_status_change_check(dev, 0);
}

static int fec_enet_open(struct net_device *dev)
{
        struct fec_enet_private *fep = netdev_priv(dev);
        const struct fec_platform_info *fpi = fep->fpi;
        unsigned long flags;

        napi_enable(&fep->napi);

        /* Install our interrupt handler. */
        if (request_irq(fpi->fec_irq, fec_enet_interrupt, 0, "fec", dev) != 0) {
                printk(KERN_ERR DRV_MODULE_NAME
                       ": %s Could not allocate FEC IRQ!", dev->name);
                napi_disable(&fep->napi);
                return -EINVAL;
        }

        /* Install our phy interrupt handler */
        if (fpi->phy_irq != -1 && 
                request_irq(fpi->phy_irq, fec_mii_link_interrupt, 0, "fec-phy",
                                dev) != 0) {
                printk(KERN_ERR DRV_MODULE_NAME
                       ": %s Could not allocate PHY IRQ!", dev->name);
                free_irq(fpi->fec_irq, dev);
                napi_disable(&fep->napi);
                return -EINVAL;
        }

        if (fpi->use_mdio) {
                fec_mii_startup(dev);
                netif_carrier_off(dev);
                fec_mii_link_status_change_check(dev, 1);
        } else {
                spin_lock_irqsave(&fep->lock, flags);
                fec_restart(dev, 1, 100);       /* XXX this sucks */
                spin_unlock_irqrestore(&fep->lock, flags);

                netif_carrier_on(dev);
                netif_start_queue(dev);
        }
        return 0;
}

static int fec_enet_close(struct net_device *dev)
{
        struct fec_enet_private *fep = netdev_priv(dev);
        const struct fec_platform_info *fpi = fep->fpi;
        unsigned long flags;

        netif_stop_queue(dev);
        napi_disable(&fep->napi);
        netif_carrier_off(dev);

        if (fpi->use_mdio)
                fec_mii_shutdown(dev);

        spin_lock_irqsave(&fep->lock, flags);
        fec_stop(dev);
        spin_unlock_irqrestore(&fep->lock, flags);

        /* release any irqs */
        if (fpi->phy_irq != -1)
                free_irq(fpi->phy_irq, dev);
        free_irq(fpi->fec_irq, dev);

        return 0;
}

static struct net_device_stats *fec_enet_get_stats(struct net_device *dev)
{
        struct fec_enet_private *fep = netdev_priv(dev);
        return &fep->stats;
}

static int fec_enet_poll(struct napi_struct *napi, int budget)
{
        struct fec_enet_private *fep = container_of(napi, struct fec_enet_private, napi);
        struct net_device *dev = fep->dev;

        return fec_enet_rx_common(fep, dev, budget);
}

/*************************************************************************/

static void fec_get_drvinfo(struct net_device *dev,
                            struct ethtool_drvinfo *info)
{
        strcpy(info->driver, DRV_MODULE_NAME);
        strcpy(info->version, DRV_MODULE_VERSION);
}

static int fec_get_regs_len(struct net_device *dev)
{
        return sizeof(fec_t);
}

static void fec_get_regs(struct net_device *dev, struct ethtool_regs *regs,
                         void *p)
{
        struct fec_enet_private *fep = netdev_priv(dev);
        unsigned long flags;

        if (regs->len < sizeof(fec_t))
                return;

        regs->version = 0;
        spin_lock_irqsave(&fep->lock, flags);
        memcpy_fromio(p, fep->fecp, sizeof(fec_t));
        spin_unlock_irqrestore(&fep->lock, flags);
}

static int fec_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
        struct fec_enet_private *fep = netdev_priv(dev);
        unsigned long flags;
        int rc;

        spin_lock_irqsave(&fep->lock, flags);
        rc = mii_ethtool_gset(&fep->mii_if, cmd);
        spin_unlock_irqrestore(&fep->lock, flags);

        return rc;
}

static int fec_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{

        struct fec_enet_private *fep = netdev_priv(dev);
        unsigned long flags;
        int rc;

        spin_lock_irqsave(&fep->lock, flags);
        rc = mii_ethtool_sset(&fep->mii_if, cmd);
        spin_unlock_irqrestore(&fep->lock, flags);

        return rc;
}

static int fec_nway_reset(struct net_device *dev)
{
        struct fec_enet_private *fep = netdev_priv(dev);
        return mii_nway_restart(&fep->mii_if);
}

static __u32 fec_get_msglevel(struct net_device *dev)
{
        struct fec_enet_private *fep = netdev_priv(dev);
        return fep->msg_enable;
}

static void fec_set_msglevel(struct net_device *dev, __u32 value)
{
        struct fec_enet_private *fep = netdev_priv(dev);
        fep->msg_enable = value;
}

static const struct ethtool_ops fec_ethtool_ops = {
        .get_drvinfo    = fec_get_drvinfo,
        .get_regs_len   = fec_get_regs_len,
        .get_settings   = fec_get_settings,
        .set_settings   = fec_set_settings,
        .nway_reset     = fec_nway_reset,
        .get_link       = ethtool_op_get_link,
        .get_msglevel   = fec_get_msglevel,
        .set_msglevel   = fec_set_msglevel,
        .set_tx_csum    = ethtool_op_set_tx_csum,       /* local! */
        .set_sg         = ethtool_op_set_sg,
        .get_regs       = fec_get_regs,
};

static int fec_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
{
        struct fec_enet_private *fep = netdev_priv(dev);
        struct mii_ioctl_data *mii = (struct mii_ioctl_data *)&rq->ifr_data;
        unsigned long flags;
        int rc;

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

        spin_lock_irqsave(&fep->lock, flags);
        rc = generic_mii_ioctl(&fep->mii_if, mii, cmd, NULL);
        spin_unlock_irqrestore(&fep->lock, flags);
        return rc;
}

int fec_8xx_init_one(const struct fec_platform_info *fpi,
                     struct net_device **devp)
{
        immap_t *immap = (immap_t *) IMAP_ADDR;
        static int fec_8xx_version_printed = 0;
        struct net_device *dev = NULL;
        struct fec_enet_private *fep = NULL;
        fec_t *fecp = NULL;
        int i;
        int err = 0;
        int registered = 0;
        __u32 siel;

        *devp = NULL;

        switch (fpi->fec_no) {
        case 0:
                fecp = &((immap_t *) IMAP_ADDR)->im_cpm.cp_fec;
                break;
#ifdef CONFIG_DUET
        case 1:
                fecp = &((immap_t *) IMAP_ADDR)->im_cpm.cp_fec2;
                break;
#endif
        default:
                return -EINVAL;
        }

        if (fec_8xx_version_printed++ == 0)
                printk(KERN_INFO "%s", version);

        i = sizeof(*fep) + (sizeof(struct sk_buff **) *
                            (fpi->rx_ring + fpi->tx_ring));

        dev = alloc_etherdev(i);
        if (!dev) {
                err = -ENOMEM;
                goto err;
        }

        fep = netdev_priv(dev);
        fep->dev = dev;

        /* partial reset of FEC */
        fec_whack_reset(fecp);

        /* point rx_skbuff, tx_skbuff */
        fep->rx_skbuff = (struct sk_buff **)&fep[1];
        fep->tx_skbuff = fep->rx_skbuff + fpi->rx_ring;

        fep->fecp = fecp;
        fep->fpi = fpi;

        /* init locks */
        spin_lock_init(&fep->lock);
        spin_lock_init(&fep->tx_lock);

        /*
         * Set the Ethernet address. 
         */
        for (i = 0; i < 6; i++)
                dev->dev_addr[i] = fpi->macaddr[i];

        fep->ring_base = dma_alloc_coherent(NULL,
                                            (fpi->tx_ring + fpi->rx_ring) *
                                            sizeof(cbd_t), &fep->ring_mem_addr,
                                            GFP_KERNEL);
        if (fep->ring_base == NULL) {
                printk(KERN_ERR DRV_MODULE_NAME
                       ": %s dma alloc failed.\n", dev->name);
                err = -ENOMEM;
                goto err;
        }

        /*
         * Set receive and transmit descriptor base.
         */
        fep->rx_bd_base = fep->ring_base;
        fep->tx_bd_base = fep->rx_bd_base + fpi->rx_ring;

        /* initialize ring size variables */
        fep->tx_ring = fpi->tx_ring;
        fep->rx_ring = fpi->rx_ring;

        /* SIU interrupt */
        if (fpi->phy_irq != -1 &&
                (fpi->phy_irq >= SIU_IRQ0 && fpi->phy_irq < SIU_LEVEL7)) {

                siel = in_be32(&immap->im_siu_conf.sc_siel);
                if ((fpi->phy_irq & 1) == 0)
                        siel |= (0x80000000 >> fpi->phy_irq);
                else
                        siel &= ~(0x80000000 >> (fpi->phy_irq & ~1));
                out_be32(&immap->im_siu_conf.sc_siel, siel);
        }

        /*
         * The FEC Ethernet specific entries in the device structure. 
         */
        dev->open = fec_enet_open;
        dev->hard_start_xmit = fec_enet_start_xmit;
        dev->tx_timeout = fec_timeout;
        dev->watchdog_timeo = TX_TIMEOUT;
        dev->stop = fec_enet_close;
        dev->get_stats = fec_enet_get_stats;
        dev->set_multicast_list = fec_set_multicast_list;
        dev->set_mac_address = fec_set_mac_address;
        netif_napi_add(dev, &fec->napi,
                       fec_enet_poll, fpi->napi_weight);

        dev->ethtool_ops = &fec_ethtool_ops;
        dev->do_ioctl = fec_ioctl;

        fep->fec_phy_speed =
            ((((fpi->sys_clk + 4999999) / 2500000) / 2) & 0x3F) << 1;

        init_timer(&fep->phy_timer_list);

        /* partial reset of FEC so that only MII works */
        FW(fecp, mii_speed, fep->fec_phy_speed);
        FW(fecp, ievent, 0xffc0);
        FW(fecp, ivec, (fpi->fec_irq / 2) << 29);
        FW(fecp, imask, 0);
        FW(fecp, r_cntrl, FEC_RCNTRL_MII_MODE); /* MII enable */
        FW(fecp, ecntrl, FEC_ECNTRL_PINMUX | FEC_ECNTRL_ETHER_EN);

        netif_carrier_off(dev);

        err = register_netdev(dev);
        if (err != 0)
                goto err;
        registered = 1;

        if (fpi->use_mdio) {
                fep->mii_if.dev = dev;
                fep->mii_if.mdio_read = fec_mii_read;
                fep->mii_if.mdio_write = fec_mii_write;
                fep->mii_if.phy_id_mask = 0x1f;
                fep->mii_if.reg_num_mask = 0x1f;
                fep->mii_if.phy_id = fec_mii_phy_id_detect(dev);
        }

        *devp = dev;

        return 0;

      err:
        if (dev != NULL) {
                if (fecp != NULL)
                        fec_whack_reset(fecp);

                if (registered)
                        unregister_netdev(dev);

                if (fep != NULL) {
                        if (fep->ring_base)
                                dma_free_coherent(NULL,
                                                  (fpi->tx_ring +
                                                   fpi->rx_ring) *
                                                  sizeof(cbd_t), fep->ring_base,
                                                  fep->ring_mem_addr);
                }
                free_netdev(dev);
        }
        return err;
}

int fec_8xx_cleanup_one(struct net_device *dev)
{
        struct fec_enet_private *fep = netdev_priv(dev);
        fec_t *fecp = fep->fecp;
        const struct fec_platform_info *fpi = fep->fpi;

        fec_whack_reset(fecp);

        unregister_netdev(dev);

        dma_free_coherent(NULL, (fpi->tx_ring + fpi->rx_ring) * sizeof(cbd_t),
                          fep->ring_base, fep->ring_mem_addr);

        free_netdev(dev);

        return 0;
}

/**************************************************************************************/
/**************************************************************************************/
/**************************************************************************************/

static int __init fec_8xx_init(void)
{
        return fec_8xx_platform_init();
}

static void __exit fec_8xx_cleanup(void)
{
        fec_8xx_platform_cleanup();
}

/**************************************************************************************/
/**************************************************************************************/
/**************************************************************************************/

module_init(fec_8xx_init);
module_exit(fec_8xx_cleanup);