/*
 *  Amiga Linux/m68k Ariadne Ethernet Driver
 *
 *  © Copyright 1995-2003 by Geert Uytterhoeven (geert@linux-m68k.org)
 *                           Peter De Schrijver (p2@mind.be)
 *
 *  ---------------------------------------------------------------------------
 *
 *  This program is based on
 *
 *      lance.c:        An AMD LANCE ethernet driver for linux.
 *                      Written 1993-94 by Donald Becker.
 *
 *      Am79C960:       PCnet(tm)-ISA Single-Chip Ethernet Controller
 *                      Advanced Micro Devices
 *                      Publication #16907, Rev. B, Amendment/0, May 1994
 *
 *      MC68230:        Parallel Interface/Timer (PI/T)
 *                      Motorola Semiconductors, December, 1983
 *
 *  ---------------------------------------------------------------------------
 *
 *  This file is subject to the terms and conditions of the GNU General Public
 *  License.  See the file COPYING in the main directory of the Linux
 *  distribution for more details.
 *
 *  ---------------------------------------------------------------------------
 *
 *  The Ariadne is a Zorro-II board made by Village Tronic. It contains:
 *
 *      - an Am79C960 PCnet-ISA Single-Chip Ethernet Controller with both
 *        10BASE-2 (thin coax) and 10BASE-T (UTP) connectors
 *
 *      - an MC68230 Parallel Interface/Timer configured as 2 parallel ports
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
/*#define DEBUG*/

#include <linux/module.h>
#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/interrupt.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/zorro.h>
#include <linux/bitops.h>

#include <asm/byteorder.h>
#include <asm/amigaints.h>
#include <asm/amigahw.h>
#include <asm/irq.h>

#include "ariadne.h"

#ifdef ARIADNE_DEBUG
int ariadne_debug = ARIADNE_DEBUG;
#else
int ariadne_debug = 1;
#endif

/* Macros to Fix Endianness problems */

/* Swap the Bytes in a WORD */
#define swapw(x)        (((x >> 8) & 0x00ff) | ((x << 8) & 0xff00))
/* Get the Low BYTE in a WORD */
#define lowb(x)         (x & 0xff)
/* Get the Swapped High WORD in a LONG */
#define swhighw(x)      ((((x) >> 8) & 0xff00) | (((x) >> 24) & 0x00ff))
/* Get the Swapped Low WORD in a LONG */
#define swloww(x)       ((((x) << 8) & 0xff00) | (((x) >> 8) & 0x00ff))

/* Transmit/Receive Ring Definitions */

#define TX_RING_SIZE    5
#define RX_RING_SIZE    16

#define PKT_BUF_SIZE    1520

/* Private Device Data */

struct ariadne_private {
        volatile struct TDRE *tx_ring[TX_RING_SIZE];
        volatile struct RDRE *rx_ring[RX_RING_SIZE];
        volatile u_short *tx_buff[TX_RING_SIZE];
        volatile u_short *rx_buff[RX_RING_SIZE];
        int cur_tx, cur_rx;             /* The next free ring entry */
        int dirty_tx;                   /* The ring entries to be free()ed */
        char tx_full;
};

/* Structure Created in the Ariadne's RAM Buffer */

struct lancedata {
        struct TDRE tx_ring[TX_RING_SIZE];
        struct RDRE rx_ring[RX_RING_SIZE];
        u_short tx_buff[TX_RING_SIZE][PKT_BUF_SIZE / sizeof(u_short)];
        u_short rx_buff[RX_RING_SIZE][PKT_BUF_SIZE / sizeof(u_short)];
};

static void memcpyw(volatile u_short *dest, u_short *src, int len)
{
        while (len >= 2) {
                *(dest++) = *(src++);
                len -= 2;
        }
        if (len == 1)
                *dest = (*(u_char *)src) << 8;
}

static void ariadne_init_ring(struct net_device *dev)
{
        struct ariadne_private *priv = netdev_priv(dev);
        volatile struct lancedata *lancedata = (struct lancedata *)dev->mem_start;
        int i;

        netif_stop_queue(dev);

        priv->tx_full = 0;
        priv->cur_rx = priv->cur_tx = 0;
        priv->dirty_tx = 0;

        /* Set up TX Ring */
        for (i = 0; i < TX_RING_SIZE; i++) {
                volatile struct TDRE *t = &lancedata->tx_ring[i];
                t->TMD0 = swloww(ARIADNE_RAM +
                                 offsetof(struct lancedata, tx_buff[i]));
                t->TMD1 = swhighw(ARIADNE_RAM +
                                  offsetof(struct lancedata, tx_buff[i])) |
                        TF_STP | TF_ENP;
                t->TMD2 = swapw((u_short)-PKT_BUF_SIZE);
                t->TMD3 = 0;
                priv->tx_ring[i] = &lancedata->tx_ring[i];
                priv->tx_buff[i] = lancedata->tx_buff[i];
                netdev_dbg(dev, "TX Entry %2d at %p, Buf at %p\n",
                           i, &lancedata->tx_ring[i], lancedata->tx_buff[i]);
        }

        /* Set up RX Ring */
        for (i = 0; i < RX_RING_SIZE; i++) {
                volatile struct RDRE *r = &lancedata->rx_ring[i];
                r->RMD0 = swloww(ARIADNE_RAM +
                                 offsetof(struct lancedata, rx_buff[i]));
                r->RMD1 = swhighw(ARIADNE_RAM +
                                  offsetof(struct lancedata, rx_buff[i])) |
                        RF_OWN;
                r->RMD2 = swapw((u_short)-PKT_BUF_SIZE);
                r->RMD3 = 0x0000;
                priv->rx_ring[i] = &lancedata->rx_ring[i];
                priv->rx_buff[i] = lancedata->rx_buff[i];
                netdev_dbg(dev, "RX Entry %2d at %p, Buf at %p\n",
                           i, &lancedata->rx_ring[i], lancedata->rx_buff[i]);
        }
}

static int ariadne_rx(struct net_device *dev)
{
        struct ariadne_private *priv = netdev_priv(dev);
        int entry = priv->cur_rx % RX_RING_SIZE;
        int i;

        /* If we own the next entry, it's a new packet. Send it up */
        while (!(lowb(priv->rx_ring[entry]->RMD1) & RF_OWN)) {
                int status = lowb(priv->rx_ring[entry]->RMD1);

                if (status != (RF_STP | RF_ENP)) {      /* There was an error */
                        /* There is a tricky error noted by
                         * John Murphy <murf@perftech.com> to Russ Nelson:
                         * Even with full-sized buffers it's possible for a
                         * jabber packet to use two buffers, with only the
                         * last correctly noting the error
                         */
                        /* Only count a general error at the end of a packet */
                        if (status & RF_ENP)
                                dev->stats.rx_errors++;
                        if (status & RF_FRAM)
                                dev->stats.rx_frame_errors++;
                        if (status & RF_OFLO)
                                dev->stats.rx_over_errors++;
                        if (status & RF_CRC)
                                dev->stats.rx_crc_errors++;
                        if (status & RF_BUFF)
                                dev->stats.rx_fifo_errors++;
                        priv->rx_ring[entry]->RMD1 &= 0xff00 | RF_STP | RF_ENP;
                } else {
                        /* Malloc up new buffer, compatible with net-3 */
                        short pkt_len = swapw(priv->rx_ring[entry]->RMD3);
                        struct sk_buff *skb;

                        skb = netdev_alloc_skb(dev, pkt_len + 2);
                        if (!skb) {
                                for (i = 0; i < RX_RING_SIZE; i++)
                                        if (lowb(priv->rx_ring[(entry + i) % RX_RING_SIZE]->RMD1) & RF_OWN)
                                                break;

                                if (i > RX_RING_SIZE - 2) {
                                        dev->stats.rx_dropped++;
                                        priv->rx_ring[entry]->RMD1 |= RF_OWN;
                                        priv->cur_rx++;
                                }
                                break;
                        }


                        skb_reserve(skb, 2);    /* 16 byte align */
                        skb_put(skb, pkt_len);  /* Make room */
                        skb_copy_to_linear_data(skb,
                                                (const void *)priv->rx_buff[entry],
                                                pkt_len);
                        skb->protocol = eth_type_trans(skb, dev);
                        netdev_dbg(dev, "RX pkt type 0x%04x from %pM to %pM data %p len %u\n",
                                   ((u_short *)skb->data)[6],
                                   skb->data + 6, skb->data,
                                   skb->data, skb->len);

                        netif_rx(skb);
                        dev->stats.rx_packets++;
                        dev->stats.rx_bytes += pkt_len;
                }

                priv->rx_ring[entry]->RMD1 |= RF_OWN;
                entry = (++priv->cur_rx) % RX_RING_SIZE;
        }

        priv->cur_rx = priv->cur_rx % RX_RING_SIZE;

        /* We should check that at least two ring entries are free.
         * If not, we should free one and mark stats->rx_dropped++
         */

        return 0;
}

static irqreturn_t ariadne_interrupt(int irq, void *data)
{
        struct net_device *dev = (struct net_device *)data;
        volatile struct Am79C960 *lance = (struct Am79C960 *)dev->base_addr;
        struct ariadne_private *priv;
        int csr0, boguscnt;
        int handled = 0;

        lance->RAP = CSR0;              /* PCnet-ISA Controller Status */

        if (!(lance->RDP & INTR))       /* Check if any interrupt has been */
                return IRQ_NONE;        /* generated by the board */

        priv = netdev_priv(dev);

        boguscnt = 10;
        while ((csr0 = lance->RDP) & (ERR | RINT | TINT) && --boguscnt >= 0) {
                /* Acknowledge all of the current interrupt sources ASAP */
                lance->RDP = csr0 & ~(INEA | TDMD | STOP | STRT | INIT);

#ifdef DEBUG
                if (ariadne_debug > 5) {
                        netdev_dbg(dev, "interrupt  csr0=%#02x new csr=%#02x [",
                                   csr0, lance->RDP);
                        if (csr0 & INTR)
                                pr_cont(" INTR");
                        if (csr0 & INEA)
                                pr_cont(" INEA");
                        if (csr0 & RXON)
                                pr_cont(" RXON");
                        if (csr0 & TXON)
                                pr_cont(" TXON");
                        if (csr0 & TDMD)
                                pr_cont(" TDMD");
                        if (csr0 & STOP)
                                pr_cont(" STOP");
                        if (csr0 & STRT)
                                pr_cont(" STRT");
                        if (csr0 & INIT)
                                pr_cont(" INIT");
                        if (csr0 & ERR)
                                pr_cont(" ERR");
                        if (csr0 & BABL)
                                pr_cont(" BABL");
                        if (csr0 & CERR)
                                pr_cont(" CERR");
                        if (csr0 & MISS)
                                pr_cont(" MISS");
                        if (csr0 & MERR)
                                pr_cont(" MERR");
                        if (csr0 & RINT)
                                pr_cont(" RINT");
                        if (csr0 & TINT)
                                pr_cont(" TINT");
                        if (csr0 & IDON)
                                pr_cont(" IDON");
                        pr_cont(" ]\n");
                }
#endif

                if (csr0 & RINT) {      /* Rx interrupt */
                        handled = 1;
                        ariadne_rx(dev);
                }

                if (csr0 & TINT) {      /* Tx-done interrupt */
                        int dirty_tx = priv->dirty_tx;

                        handled = 1;
                        while (dirty_tx < priv->cur_tx) {
                                int entry = dirty_tx % TX_RING_SIZE;
                                int status = lowb(priv->tx_ring[entry]->TMD1);

                                if (status & TF_OWN)
                                        break;  /* It still hasn't been Txed */

                                priv->tx_ring[entry]->TMD1 &= 0xff00;

                                if (status & TF_ERR) {
                                        /* There was an major error, log it */
                                        int err_status = priv->tx_ring[entry]->TMD3;
                                        dev->stats.tx_errors++;
                                        if (err_status & EF_RTRY)
                                                dev->stats.tx_aborted_errors++;
                                        if (err_status & EF_LCAR)
                                                dev->stats.tx_carrier_errors++;
                                        if (err_status & EF_LCOL)
                                                dev->stats.tx_window_errors++;
                                        if (err_status & EF_UFLO) {
                                                /* Ackk!  On FIFO errors the Tx unit is turned off! */
                                                dev->stats.tx_fifo_errors++;
                                                /* Remove this verbosity later! */
                                                netdev_err(dev, "Tx FIFO error! Status %04x\n",
                                                           csr0);
                                                /* Restart the chip */
                                                lance->RDP = STRT;
                                        }
                                } else {
                                        if (status & (TF_MORE | TF_ONE))
                                                dev->stats.collisions++;
                                        dev->stats.tx_packets++;
                                }
                                dirty_tx++;
                        }

#ifndef final_version
                        if (priv->cur_tx - dirty_tx >= TX_RING_SIZE) {
                                netdev_err(dev, "out-of-sync dirty pointer, %d vs. %d, full=%d\n",
                                           dirty_tx, priv->cur_tx,
                                           priv->tx_full);
                                dirty_tx += TX_RING_SIZE;
                        }
#endif

                        if (priv->tx_full && netif_queue_stopped(dev) &&
                            dirty_tx > priv->cur_tx - TX_RING_SIZE + 2) {
                                /* The ring is no longer full */
                                priv->tx_full = 0;
                                netif_wake_queue(dev);
                        }

                        priv->dirty_tx = dirty_tx;
                }

                /* Log misc errors */
                if (csr0 & BABL) {
                        handled = 1;
                        dev->stats.tx_errors++; /* Tx babble */
                }
                if (csr0 & MISS) {
                        handled = 1;
                        dev->stats.rx_errors++; /* Missed a Rx frame */
                }
                if (csr0 & MERR) {
                        handled = 1;
                        netdev_err(dev, "Bus master arbitration failure, status %04x\n",
                                   csr0);
                        /* Restart the chip */
                        lance->RDP = STRT;
                }
        }

        /* Clear any other interrupt, and set interrupt enable */
        lance->RAP = CSR0;              /* PCnet-ISA Controller Status */
        lance->RDP = INEA | BABL | CERR | MISS | MERR | IDON;

        if (ariadne_debug > 4)
                netdev_dbg(dev, "exiting interrupt, csr%d=%#04x\n",
                           lance->RAP, lance->RDP);

        return IRQ_RETVAL(handled);
}

static int ariadne_open(struct net_device *dev)
{
        volatile struct Am79C960 *lance = (struct Am79C960 *)dev->base_addr;
        u_short in;
        u_long version;
        int i;

        /* Reset the LANCE */
        in = lance->Reset;

        /* Stop the LANCE */
        lance->RAP = CSR0;              /* PCnet-ISA Controller Status */
        lance->RDP = STOP;

        /* Check the LANCE version */
        lance->RAP = CSR88;             /* Chip ID */
        version = swapw(lance->RDP);
        lance->RAP = CSR89;             /* Chip ID */
        version |= swapw(lance->RDP) << 16;
        if ((version & 0x00000fff) != 0x00000003) {
                pr_warn("Couldn't find AMD Ethernet Chip\n");
                return -EAGAIN;
        }
        if ((version & 0x0ffff000) != 0x00003000) {
                pr_warn("Couldn't find Am79C960 (Wrong part number = %ld)\n",
                       (version & 0x0ffff000) >> 12);
                return -EAGAIN;
        }

        netdev_dbg(dev, "Am79C960 (PCnet-ISA) Revision %ld\n",
                   (version & 0xf0000000) >> 28);

        ariadne_init_ring(dev);

        /* Miscellaneous Stuff */
        lance->RAP = CSR3;              /* Interrupt Masks and Deferral Control */
        lance->RDP = 0x0000;
        lance->RAP = CSR4;              /* Test and Features Control */
        lance->RDP = DPOLL | APAD_XMT | MFCOM | RCVCCOM | TXSTRTM | JABM;

        /* Set the Multicast Table */
        lance->RAP = CSR8;              /* Logical Address Filter, LADRF[15:0] */
        lance->RDP = 0x0000;
        lance->RAP = CSR9;              /* Logical Address Filter, LADRF[31:16] */
        lance->RDP = 0x0000;
        lance->RAP = CSR10;             /* Logical Address Filter, LADRF[47:32] */
        lance->RDP = 0x0000;
        lance->RAP = CSR11;             /* Logical Address Filter, LADRF[63:48] */
        lance->RDP = 0x0000;

        /* Set the Ethernet Hardware Address */
        lance->RAP = CSR12;             /* Physical Address Register, PADR[15:0] */
        lance->RDP = ((const u_short *)&dev->dev_addr[0])[0];
        lance->RAP = CSR13;             /* Physical Address Register, PADR[31:16] */
        lance->RDP = ((const u_short *)&dev->dev_addr[0])[1];
        lance->RAP = CSR14;             /* Physical Address Register, PADR[47:32] */
        lance->RDP = ((const u_short *)&dev->dev_addr[0])[2];

        /* Set the Init Block Mode */
        lance->RAP = CSR15;             /* Mode Register */
        lance->RDP = 0x0000;

        /* Set the Transmit Descriptor Ring Pointer */
        lance->RAP = CSR30;             /* Base Address of Transmit Ring */
        lance->RDP = swloww(ARIADNE_RAM + offsetof(struct lancedata, tx_ring));
        lance->RAP = CSR31;             /* Base Address of transmit Ring */
        lance->RDP = swhighw(ARIADNE_RAM + offsetof(struct lancedata, tx_ring));

        /* Set the Receive Descriptor Ring Pointer */
        lance->RAP = CSR24;             /* Base Address of Receive Ring */
        lance->RDP = swloww(ARIADNE_RAM + offsetof(struct lancedata, rx_ring));
        lance->RAP = CSR25;             /* Base Address of Receive Ring */
        lance->RDP = swhighw(ARIADNE_RAM + offsetof(struct lancedata, rx_ring));

        /* Set the Number of RX and TX Ring Entries */
        lance->RAP = CSR76;             /* Receive Ring Length */
        lance->RDP = swapw(((u_short)-RX_RING_SIZE));
        lance->RAP = CSR78;             /* Transmit Ring Length */
        lance->RDP = swapw(((u_short)-TX_RING_SIZE));

        /* Enable Media Interface Port Auto Select (10BASE-2/10BASE-T) */
        lance->RAP = ISACSR2;           /* Miscellaneous Configuration */
        lance->IDP = ASEL;

        /* LED Control */
        lance->RAP = ISACSR5;           /* LED1 Status */
        lance->IDP = PSE|XMTE;
        lance->RAP = ISACSR6;   /* LED2 Status */
        lance->IDP = PSE|COLE;
        lance->RAP = ISACSR7;   /* LED3 Status */
        lance->IDP = PSE|RCVE;

        netif_start_queue(dev);

        i = request_irq(IRQ_AMIGA_PORTS, ariadne_interrupt, IRQF_SHARED,
                        dev->name, dev);
        if (i)
                return i;

        lance->RAP = CSR0;              /* PCnet-ISA Controller Status */
        lance->RDP = INEA | STRT;

        return 0;
}

static int ariadne_close(struct net_device *dev)
{
        volatile struct Am79C960 *lance = (struct Am79C960 *)dev->base_addr;

        netif_stop_queue(dev);

        lance->RAP = CSR112;            /* Missed Frame Count */
        dev->stats.rx_missed_errors = swapw(lance->RDP);
        lance->RAP = CSR0;              /* PCnet-ISA Controller Status */

        if (ariadne_debug > 1) {
                netdev_dbg(dev, "Shutting down ethercard, status was %02x\n",
                           lance->RDP);
                netdev_dbg(dev, "%lu packets missed\n",
                           dev->stats.rx_missed_errors);
        }

        /* We stop the LANCE here -- it occasionally polls memory if we don't */
        lance->RDP = STOP;

        free_irq(IRQ_AMIGA_PORTS, dev);

        return 0;
}

static inline void ariadne_reset(struct net_device *dev)
{
        volatile struct Am79C960 *lance = (struct Am79C960 *)dev->base_addr;

        lance->RAP = CSR0;      /* PCnet-ISA Controller Status */
        lance->RDP = STOP;
        ariadne_init_ring(dev);
        lance->RDP = INEA | STRT;
        netif_start_queue(dev);
}

static void ariadne_tx_timeout(struct net_device *dev, unsigned int txqueue)
{
        volatile struct Am79C960 *lance = (struct Am79C960 *)dev->base_addr;

        netdev_err(dev, "transmit timed out, status %04x, resetting\n",
                   lance->RDP);
        ariadne_reset(dev);
        netif_wake_queue(dev);
}

static netdev_tx_t ariadne_start_xmit(struct sk_buff *skb,
                                      struct net_device *dev)
{
        struct ariadne_private *priv = netdev_priv(dev);
        volatile struct Am79C960 *lance = (struct Am79C960 *)dev->base_addr;
        int entry;
        unsigned long flags;
        int len = skb->len;

#if 0
        if (ariadne_debug > 3) {
                lance->RAP = CSR0;      /* PCnet-ISA Controller Status */
                netdev_dbg(dev, "%s: csr0 %04x\n", __func__, lance->RDP);
                lance->RDP = 0x0000;
        }
#endif

        /* FIXME: is the 79C960 new enough to do its own padding right ? */
        if (skb->len < ETH_ZLEN) {
                if (skb_padto(skb, ETH_ZLEN))
                        return NETDEV_TX_OK;
                len = ETH_ZLEN;
        }

        /* Fill in a Tx ring entry */

        netdev_dbg(dev, "TX pkt type 0x%04x from %pM to %pM data %p len %u\n",
                   ((u_short *)skb->data)[6],
                   skb->data + 6, skb->data,
                   skb->data, skb->len);

        local_irq_save(flags);

        entry = priv->cur_tx % TX_RING_SIZE;

        /* Caution: the write order is important here, set the base address with
           the "ownership" bits last */

        priv->tx_ring[entry]->TMD2 = swapw((u_short)-skb->len);
        priv->tx_ring[entry]->TMD3 = 0x0000;
        memcpyw(priv->tx_buff[entry], (u_short *)skb->data, len);

#ifdef DEBUG
        print_hex_dump(KERN_DEBUG, "tx_buff: ", DUMP_PREFIX_OFFSET, 16, 1,
                       (void *)priv->tx_buff[entry],
                       skb->len > 64 ? 64 : skb->len, true);
#endif

        priv->tx_ring[entry]->TMD1 = (priv->tx_ring[entry]->TMD1 & 0xff00)
                | TF_OWN | TF_STP | TF_ENP;

        dev_kfree_skb(skb);

        priv->cur_tx++;
        if ((priv->cur_tx >= TX_RING_SIZE) &&
            (priv->dirty_tx >= TX_RING_SIZE)) {

                netdev_dbg(dev, "*** Subtracting TX_RING_SIZE from cur_tx (%d) and dirty_tx (%d)\n",
                           priv->cur_tx, priv->dirty_tx);

                priv->cur_tx -= TX_RING_SIZE;
                priv->dirty_tx -= TX_RING_SIZE;
        }
        dev->stats.tx_bytes += len;

        /* Trigger an immediate send poll */
        lance->RAP = CSR0;              /* PCnet-ISA Controller Status */
        lance->RDP = INEA | TDMD;

        if (lowb(priv->tx_ring[(entry + 1) % TX_RING_SIZE]->TMD1) != 0) {
                netif_stop_queue(dev);
                priv->tx_full = 1;
        }
        local_irq_restore(flags);

        return NETDEV_TX_OK;
}

static struct net_device_stats *ariadne_get_stats(struct net_device *dev)
{
        volatile struct Am79C960 *lance = (struct Am79C960 *)dev->base_addr;
        short saved_addr;
        unsigned long flags;

        local_irq_save(flags);
        saved_addr = lance->RAP;
        lance->RAP = CSR112;            /* Missed Frame Count */
        dev->stats.rx_missed_errors = swapw(lance->RDP);
        lance->RAP = saved_addr;
        local_irq_restore(flags);

        return &dev->stats;
}

/* Set or clear the multicast filter for this adaptor.
 * num_addrs == -1      Promiscuous mode, receive all packets
 * num_addrs == 0       Normal mode, clear multicast list
 * num_addrs > 0        Multicast mode, receive normal and MC packets,
 *                      and do best-effort filtering.
 */
static void set_multicast_list(struct net_device *dev)
{
        volatile struct Am79C960 *lance = (struct Am79C960 *)dev->base_addr;

        if (!netif_running(dev))
                return;

        netif_stop_queue(dev);

        /* We take the simple way out and always enable promiscuous mode */
        lance->RAP = CSR0;              /* PCnet-ISA Controller Status */
        lance->RDP = STOP;              /* Temporarily stop the lance */
        ariadne_init_ring(dev);

        if (dev->flags & IFF_PROMISC) {
                lance->RAP = CSR15;     /* Mode Register */
                lance->RDP = PROM;      /* Set promiscuous mode */
        } else {
                short multicast_table[4];
                int num_addrs = netdev_mc_count(dev);
                int i;
                /* We don't use the multicast table,
                 * but rely on upper-layer filtering
                 */
                memset(multicast_table, (num_addrs == 0) ? 0 : -1,
                       sizeof(multicast_table));
                for (i = 0; i < 4; i++) {
                        lance->RAP = CSR8 + (i << 8);
                                        /* Logical Address Filter */
                        lance->RDP = swapw(multicast_table[i]);
                }
                lance->RAP = CSR15;     /* Mode Register */
                lance->RDP = 0x0000;    /* Unset promiscuous mode */
        }

        lance->RAP = CSR0;              /* PCnet-ISA Controller Status */
        lance->RDP = INEA | STRT | IDON;/* Resume normal operation */

        netif_wake_queue(dev);
}


static void ariadne_remove_one(struct zorro_dev *z)
{
        struct net_device *dev = zorro_get_drvdata(z);

        unregister_netdev(dev);
        release_mem_region(ZTWO_PADDR(dev->base_addr), sizeof(struct Am79C960));
        release_mem_region(ZTWO_PADDR(dev->mem_start), ARIADNE_RAM_SIZE);
        free_netdev(dev);
}

static const struct zorro_device_id ariadne_zorro_tbl[] = {
        { ZORRO_PROD_VILLAGE_TRONIC_ARIADNE },
        { 0 }
};
MODULE_DEVICE_TABLE(zorro, ariadne_zorro_tbl);

static const struct net_device_ops ariadne_netdev_ops = {
        .ndo_open               = ariadne_open,
        .ndo_stop               = ariadne_close,
        .ndo_start_xmit         = ariadne_start_xmit,
        .ndo_tx_timeout         = ariadne_tx_timeout,
        .ndo_get_stats          = ariadne_get_stats,
        .ndo_set_rx_mode        = set_multicast_list,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_set_mac_address    = eth_mac_addr,
};

static int ariadne_init_one(struct zorro_dev *z,
                            const struct zorro_device_id *ent)
{
        unsigned long board = z->resource.start;
        unsigned long base_addr = board + ARIADNE_LANCE;
        unsigned long mem_start = board + ARIADNE_RAM;
        struct resource *r1, *r2;
        struct net_device *dev;
        u8 addr[ETH_ALEN];
        u32 serial;
        int err;

        r1 = request_mem_region(base_addr, sizeof(struct Am79C960), "Am79C960");
        if (!r1)
                return -EBUSY;
        r2 = request_mem_region(mem_start, ARIADNE_RAM_SIZE, "RAM");
        if (!r2) {
                release_mem_region(base_addr, sizeof(struct Am79C960));
                return -EBUSY;
        }

        dev = alloc_etherdev(sizeof(struct ariadne_private));
        if (!dev) {
                release_mem_region(base_addr, sizeof(struct Am79C960));
                release_mem_region(mem_start, ARIADNE_RAM_SIZE);
                return -ENOMEM;
        }

        r1->name = dev->name;
        r2->name = dev->name;

        serial = be32_to_cpu(z->rom.er_SerialNumber);
        addr[0] = 0x00;
        addr[1] = 0x60;
        addr[2] = 0x30;
        addr[3] = (serial >> 16) & 0xff;
        addr[4] = (serial >> 8) & 0xff;
        addr[5] = serial & 0xff;
        eth_hw_addr_set(dev, addr);
        dev->base_addr = (unsigned long)ZTWO_VADDR(base_addr);
        dev->mem_start = (unsigned long)ZTWO_VADDR(mem_start);
        dev->mem_end = dev->mem_start + ARIADNE_RAM_SIZE;

        dev->netdev_ops = &ariadne_netdev_ops;
        dev->watchdog_timeo = 5 * HZ;

        err = register_netdev(dev);
        if (err) {
                release_mem_region(base_addr, sizeof(struct Am79C960));
                release_mem_region(mem_start, ARIADNE_RAM_SIZE);
                free_netdev(dev);
                return err;
        }
        zorro_set_drvdata(z, dev);

        netdev_info(dev, "Ariadne at 0x%08lx, Ethernet Address %pM\n",
                    board, dev->dev_addr);

        return 0;
}

static struct zorro_driver ariadne_driver = {
        .name           = "ariadne",
        .id_table       = ariadne_zorro_tbl,
        .probe          = ariadne_init_one,
        .remove         = ariadne_remove_one,
};

static int __init ariadne_init_module(void)
{
        return zorro_register_driver(&ariadne_driver);
}

static void __exit ariadne_cleanup_module(void)
{
        zorro_unregister_driver(&ariadne_driver);
}

module_init(ariadne_init_module);
module_exit(ariadne_cleanup_module);

MODULE_DESCRIPTION("Ariadne Ethernet Driver");
MODULE_LICENSE("GPL");