/* at1700.c: A network device driver for  the Allied Telesis AT1700.

        Written 1993-98 by Donald Becker.

        Copyright 1993 United States Government as represented by the
        Director, National Security Agency.

        This software may be used and distributed according to the terms
        of the GNU General Public License, incorporated herein by reference.

        The author may be reached as becker@scyld.com, or C/O
        Scyld Computing Corporation
        410 Severn Ave., Suite 210
        Annapolis MD 21403

        This is a device driver for the Allied Telesis AT1700, and
        Fujitsu FMV-181/182/181A/182A/183/184/183A/184A, which are
        straight-forward Fujitsu MB86965 implementations.

        Modification for Fujitsu FMV-18X cards is done by Yutaka Tamiya
        (tamy@flab.fujitsu.co.jp). 

  Sources:
    The Fujitsu MB86965 datasheet.

        After the initial version of this driver was written Gerry Sawkins of
        ATI provided their EEPROM configuration code header file.
    Thanks to NIIBE Yutaka <gniibe@mri.co.jp> for bug fixes.

    MCA bus (AT1720) support by Rene Schmit <rene@bss.lu>

  Bugs:
        The MB86965 has a design flaw that makes all probes unreliable.  Not
        only is it difficult to detect, it also moves around in I/O space in
        response to inb()s from other device probes!
*/
/*
        99/03/03  Allied Telesis RE1000 Plus support by T.Hagawa
        99/12/30        port to 2.3.35 by K.Takai
*/

#include <linux/config.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/mca-legacy.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/crc32.h>

#include <asm/system.h>
#include <asm/bitops.h>
#include <asm/io.h>
#include <asm/dma.h>

static char version[] __initdata =
        "at1700.c:v1.15 4/7/98  Donald Becker (becker@cesdis.gsfc.nasa.gov)\n";

/* Tunable parameters. */

/* When to switch from the 64-entry multicast filter to Rx-all-multicast. */
#define MC_FILTERBREAK 64

/* These unusual address orders are used to verify the CONFIG register. */

static int fmv18x_probe_list[] __initdata = {
        0x220, 0x240, 0x260, 0x280, 0x2a0, 0x2c0, 0x300, 0x340, 0
};

/*
 *      ISA
 */

#ifndef CONFIG_X86_PC9800
static int at1700_probe_list[] __initdata = {
        0x260, 0x280, 0x2a0, 0x240, 0x340, 0x320, 0x380, 0x300, 0
};

#else /* CONFIG_X86_PC9800 */
static int at1700_probe_list[] __initdata = {
        0x1d6, 0x1d8, 0x1da, 0x1d4, 0xd4, 0xd2, 0xd8, 0xd0, 0
};

#endif /* CONFIG_X86_PC9800 */
/*
 *      MCA
 */
#ifdef CONFIG_MCA       
static int at1700_ioaddr_pattern[] __initdata = {
        0x00, 0x04, 0x01, 0x05, 0x02, 0x06, 0x03, 0x07
};

static int at1700_mca_probe_list[] __initdata = {
        0x400, 0x1400, 0x2400, 0x3400, 0x4400, 0x5400, 0x6400, 0x7400, 0
};

static int at1700_irq_pattern[] __initdata = {
        0x00, 0x00, 0x00, 0x30, 0x70, 0xb0, 0x00, 0x00,
        0x00, 0xf0, 0x34, 0x74, 0xb4, 0x00, 0x00, 0xf4, 0x00
};
#endif

/* use 0 for production, 1 for verification, >2 for debug */
#ifndef NET_DEBUG
#define NET_DEBUG 1
#endif
static unsigned int net_debug = NET_DEBUG;

typedef unsigned char uchar;

/* Information that need to be kept for each board. */
struct net_local {
        struct net_device_stats stats;
        spinlock_t lock;
        unsigned char mc_filter[8];
        uint jumpered:1;                        /* Set iff the board has jumper config. */
        uint tx_started:1;                      /* Packets are on the Tx queue. */
        uint tx_queue_ready:1;                  /* Tx queue is ready to be sent. */
        uint rx_started:1;                      /* Packets are Rxing. */
        uchar tx_queue;                         /* Number of packet on the Tx queue. */
        char mca_slot;                          /* -1 means ISA */
        ushort tx_queue_len;                    /* Current length of the Tx queue. */
};


/* Offsets from the base address. */
#ifndef CONFIG_X86_PC9800
#define STATUS                  0
#define TX_STATUS               0
#define RX_STATUS               1
#define TX_INTR                 2               /* Bit-mapped interrupt enable registers. */
#define RX_INTR                 3
#define TX_MODE                 4
#define RX_MODE                 5
#define CONFIG_0                6               /* Misc. configuration settings. */
#define CONFIG_1                7
/* Run-time register bank 2 definitions. */
#define DATAPORT                8               /* Word-wide DMA or programmed-I/O dataport. */
#define TX_START                10
#define COL16CNTL               11              /* Controll Reg for 16 collisions */
#define MODE13                  13
#define RX_CTRL                 14
/* Configuration registers only on the '865A/B chips. */
#define EEPROM_Ctrl     16
#define EEPROM_Data     17
#define CARDSTATUS      16                      /* FMV-18x Card Status */
#define CARDSTATUS1     17                      /* FMV-18x Card Status */
#define IOCONFIG                18              /* Either read the jumper, or move the I/O. */
#define IOCONFIG1               19
#define SAPROM                  20              /* The station address PROM, if no EEPROM. */
#define MODE24                  24
#define RESET                   31              /* Write to reset some parts of the chip. */
#define AT1700_IO_EXTENT        32
#define PORT_OFFSET(o) (o)
#else /* CONFIG_X86_PC9800 */
#define STATUS                  (0x0000)
#define TX_STATUS               (0x0000)
#define RX_STATUS               (0x0001)
#define TX_INTR                 (0x0200)/* Bit-mapped interrupt enable registers. */
#define RX_INTR                 (0x0201)
#define TX_MODE                 (0x0400)
#define RX_MODE                 (0x0401)
#define CONFIG_0                (0x0600)/* Misc. configuration settings. */
#define CONFIG_1                (0x0601)
/* Run-time register bank 2 definitions. */
#define DATAPORT                (0x0800)/* Word-wide DMA or programmed-I/O dataport. */
#define TX_START                (0x0a00)
#define COL16CNTL               (0x0a01)/* Controll Reg for 16 collisions */
#define MODE13                  (0x0c01)
#define RX_CTRL                 (0x0e00)
/* Configuration registers only on the '865A/B chips. */
#define EEPROM_Ctrl     (0x1000)
#define EEPROM_Data     (0x1200)
#define CARDSTATUS      16                      /* FMV-18x Card Status */
#define CARDSTATUS1     17                      /* FMV-18x Card Status */
#define IOCONFIG                (0x1400)/* Either read the jumper, or move the I/O. */
#define IOCONFIG1               (0x1600)
#define SAPROM                  20              /* The station address PROM, if no EEPROM. */
#define MODE24                  (0x1800)/* The station address PROM, if no EEPROM. */
#define RESET                   (0x1e01)/* Write to reset some parts of the chip. */
#define PORT_OFFSET(o) ({ int _o_ = (o); (_o_ & ~1) * 0x100 + (_o_ & 1); })
#endif /* CONFIG_X86_PC9800 */


#define TX_TIMEOUT              10


/* Index to functions, as function prototypes. */

extern int at1700_probe(struct net_device *dev);

static int at1700_probe1(struct net_device *dev, int ioaddr);
static int read_eeprom(long ioaddr, int location);
static int net_open(struct net_device *dev);
static int      net_send_packet(struct sk_buff *skb, struct net_device *dev);
static irqreturn_t net_interrupt(int irq, void *dev_id, struct pt_regs *regs);
static void net_rx(struct net_device *dev);
static int net_close(struct net_device *dev);
static struct net_device_stats *net_get_stats(struct net_device *dev);
static void set_rx_mode(struct net_device *dev);
static void net_tx_timeout (struct net_device *dev);


#ifdef CONFIG_MCA
struct at1720_mca_adapters_struct {
        char* name;
        int id;
};
/* rEnE : maybe there are others I don't know off... */

static struct at1720_mca_adapters_struct at1720_mca_adapters[] __initdata = {
        { "Allied Telesys AT1720AT",    0x6410 },
        { "Allied Telesys AT1720BT",    0x6413 },
        { "Allied Telesys AT1720T",     0x6416 },
        { NULL, 0 },
};
#endif

/* Check for a network adaptor of this type, and return '0' iff one exists.
   If dev->base_addr == 0, probe all likely locations.
   If dev->base_addr == 1, always return failure.
   If dev->base_addr == 2, allocate space for the device and return success
   (detachable devices only).
   */

int __init at1700_probe(struct net_device *dev)
{
        int i;
        int base_addr = dev->base_addr;

        SET_MODULE_OWNER(dev);

        if (base_addr > 0x1ff)          /* Check a single specified location. */
                return at1700_probe1(dev, base_addr);
        else if (base_addr != 0)        /* Don't probe at all. */
                return -ENXIO;

        for (i = 0; at1700_probe_list[i]; i++) {
                int ioaddr = at1700_probe_list[i];
                if (at1700_probe1(dev, ioaddr) == 0)
                        return 0;
        }
        return -ENODEV;
}

/* The Fujitsu datasheet suggests that the NIC be probed for by checking its
   "signature", the default bit pattern after a reset.  This *doesn't* work --
   there is no way to reset the bus interface without a complete power-cycle!

   It turns out that ATI came to the same conclusion I did: the only thing
   that can be done is checking a few bits and then diving right into an
   EEPROM read. */

static int __init at1700_probe1(struct net_device *dev, int ioaddr)
{
        char fmv_irqmap[4] = {3, 7, 10, 15};
        char fmv_irqmap_pnp[8] = {3, 4, 5, 7, 9, 10, 11, 15};
        char at1700_irqmap[8] = {3, 4, 5, 9, 10, 11, 14, 15};
        unsigned int i, irq, is_fmv18x = 0, is_at1700 = 0;
        int slot, ret = -ENODEV;
        struct net_local *lp;
        
#ifndef CONFIG_X86_PC9800
        if (!request_region(ioaddr, AT1700_IO_EXTENT, dev->name))
                return -EBUSY;
#else
        for (i = 0; i < 0x2000; i += 0x0200) {
                if (!request_region(ioaddr + i, 2, dev->name)) {
                        while (i > 0) {
                                i -= 0x0200;
                                release_region(ioaddr + i, 2);
                        }
                        return -EBUSY;
                }
        }
#endif

                /* Resetting the chip doesn't reset the ISA interface, so don't bother.
           That means we have to be careful with the register values we probe for.
           */
#ifdef notdef
        printk("at1700 probe at %#x, eeprom is %4.4x %4.4x %4.4x ctrl %4.4x.\n",
                   ioaddr, read_eeprom(ioaddr, 4), read_eeprom(ioaddr, 5),
                   read_eeprom(ioaddr, 6), inw(ioaddr + EEPROM_Ctrl));
#endif

#ifdef CONFIG_MCA
        /* rEnE (rene@bss.lu): got this from 3c509 driver source , adapted for AT1720 */

    /* Based on Erik Nygren's (nygren@mit.edu) 3c529 patch, heavily
        modified by Chris Beauregard (cpbeaure@csclub.uwaterloo.ca)
        to support standard MCA probing. */

        /* redone for multi-card detection by ZP Gu (zpg@castle.net) */
        /* now works as a module */

        if (MCA_bus) {
                int j;
                int l_i;
                u_char pos3, pos4;

                for (j = 0; at1720_mca_adapters[j].name != NULL; j ++) {
                        slot = 0;
                        while (slot != MCA_NOTFOUND) {
                                
                                slot = mca_find_unused_adapter( at1720_mca_adapters[j].id, slot );
                                if (slot == MCA_NOTFOUND) break;

                                /* if we get this far, an adapter has been detected and is
                                enabled */

                                pos3 = mca_read_stored_pos( slot, 3 );
                                pos4 = mca_read_stored_pos( slot, 4 );

                                for (l_i = 0; l_i < 0x09; l_i++)
                                        if (( pos3 & 0x07) == at1700_ioaddr_pattern[l_i])
                                                break;
                                ioaddr = at1700_mca_probe_list[l_i];
                                
                                for (irq = 0; irq < 0x10; irq++)
                                        if (((((pos4>>4) & 0x0f) | (pos3 & 0xf0)) & 0xff) == at1700_irq_pattern[irq])
                                                break;

                                        /* probing for a card at a particular IO/IRQ */
                                if (dev &&
                                        ((dev->irq && dev->irq != irq) ||
                                         (dev->base_addr && dev->base_addr != ioaddr))) {
                                        slot++;         /* probing next slot */
                                        continue;
                                }

                                if (dev)
                                        dev->irq = irq;
                                
                                /* claim the slot */
                                mca_set_adapter_name( slot, at1720_mca_adapters[j].name );
                                mca_mark_as_used(slot);

                                goto found;
                        }
                }
                /* if we get here, we didn't find an MCA adapter - try ISA */
        }
#endif
        slot = -1;
        /* We must check for the EEPROM-config boards first, else accessing
           IOCONFIG0 will move the board! */
        if (at1700_probe_list[inb(ioaddr + IOCONFIG1) & 0x07] == ioaddr
                && read_eeprom(ioaddr, 4) == 0x0000
                && (read_eeprom(ioaddr, 5) & 0xff00) == 0xF400)
                is_at1700 = 1;
        else if (inb(ioaddr   + SAPROM    ) == 0x00
                && inb(ioaddr + SAPROM + 1) == 0x00
                && inb(ioaddr + SAPROM + 2) == 0x0e)
                is_fmv18x = 1;
        else {
                goto err_out;
        }
                        
#ifdef CONFIG_MCA
found:
#endif

                /* Reset the internal state machines. */
        outb(0, ioaddr + RESET);

        if (is_at1700) {
#ifndef CONFIG_X86_PC9800
                irq = at1700_irqmap[(read_eeprom(ioaddr, 12)&0x04)
                                                   | (read_eeprom(ioaddr, 0)>>14)];
#else
                {
                        char re1000plus_irqmap[4] = {3, 5, 6, 12};
                        irq = re1000plus_irqmap[inb(ioaddr + IOCONFIG1) >> 6];
                }
#endif
        } else {
                /* Check PnP mode for FMV-183/184/183A/184A. */
                /* This PnP routine is very poor. IO and IRQ should be known. */
                if (inb(ioaddr + CARDSTATUS1) & 0x20) {
                        irq = dev->irq;
                        for (i = 0; i < 8; i++) {
                                if (irq == fmv_irqmap_pnp[i])
                                        break;
                        }
                        if (i == 8) {
                                goto err_out;
                        }
                } else {
                        if (fmv18x_probe_list[inb(ioaddr + IOCONFIG) & 0x07] != ioaddr)
                                goto err_out;
                        irq = fmv_irqmap[(inb(ioaddr + IOCONFIG)>>6) & 0x03];
                }
        }

        printk("%s: %s found at %#3x, IRQ %d, address ", dev->name,
                   is_at1700 ? "AT1700" : "FMV-18X", ioaddr, irq);

        dev->base_addr = ioaddr;
        dev->irq = irq;

        if (is_at1700) {
                for(i = 0; i < 3; i++) {
                        unsigned short eeprom_val = read_eeprom(ioaddr, 4+i);
                        printk("%04x", eeprom_val);
                        ((unsigned short *)dev->dev_addr)[i] = ntohs(eeprom_val);
                }
        } else {
                for(i = 0; i < 6; i++) {
                        unsigned char val = inb(ioaddr + SAPROM + i);
                        printk("%02x", val);
                        dev->dev_addr[i] = val;
                }
        }

        /* The EEPROM word 12 bit 0x0400 means use regular 100 ohm 10baseT signals,
           rather than 150 ohm shielded twisted pair compensation.
           0x0000 == auto-sense the interface
           0x0800 == use TP interface
           0x1800 == use coax interface
           */
        {
                const char *porttype[] = {"auto-sense", "10baseT", "auto-sense", "10base2"};
                if (is_at1700) {
                        ushort setup_value = read_eeprom(ioaddr, 12);
                        dev->if_port = setup_value >> 8;
                } else {
                        ushort setup_value = inb(ioaddr + CARDSTATUS);
                        switch (setup_value & 0x07) {
                        case 0x01: /* 10base5 */
                        case 0x02: /* 10base2 */
                                dev->if_port = 0x18; break;
                        case 0x04: /* 10baseT */
                                dev->if_port = 0x08; break;
                        default:   /* auto-sense */
                                dev->if_port = 0x00; break;
                        }
                }
                printk(" %s interface.\n", porttype[(dev->if_port>>3) & 3]);
        }

        /* Set the configuration register 0 to 32K 100ns. byte-wide memory, 16 bit
           bus access, two 4K Tx queues, and disabled Tx and Rx. */
        outb(0xda, ioaddr + CONFIG_0);

        /* Set the station address in bank zero. */
        outb(0x00, ioaddr + CONFIG_1);
        for (i = 0; i < 6; i++)
                outb(dev->dev_addr[i], ioaddr + PORT_OFFSET(8 + i));

        /* Switch to bank 1 and set the multicast table to accept none. */
        outb(0x04, ioaddr + CONFIG_1);
        for (i = 0; i < 8; i++)
                outb(0x00, ioaddr + PORT_OFFSET(8 + i));


        /* Switch to bank 2 */
        /* Lock our I/O address, and set manual processing mode for 16 collisions. */
        outb(0x08, ioaddr + CONFIG_1);
#ifndef CONFIG_X86_PC9800
        outb(dev->if_port, ioaddr + MODE13);
#else
        outb(0, ioaddr + MODE13);
#endif
        outb(0x00, ioaddr + COL16CNTL);

        if (net_debug)
                printk(version);

        /* Initialize the device structure. */
        dev->priv = kmalloc(sizeof(struct net_local), GFP_KERNEL);
        if (dev->priv == NULL) {
                ret = -ENOMEM;
                goto err_out;
        }
        memset(dev->priv, 0, sizeof(struct net_local));

        dev->open               = net_open;
        dev->stop               = net_close;
        dev->hard_start_xmit = net_send_packet;
        dev->get_stats  = net_get_stats;
        dev->set_multicast_list = &set_rx_mode;
        dev->tx_timeout = net_tx_timeout;
        dev->watchdog_timeo = TX_TIMEOUT;

        lp = (struct net_local *)dev->priv;
        lp->lock = SPIN_LOCK_UNLOCKED;

        /* Fill in the fields of 'dev' with ethernet-generic values. */
        ether_setup(dev);

        lp->jumpered = is_fmv18x;
        lp->mca_slot = slot;
        /* Snarf the interrupt vector now. */
        ret = request_irq(irq, &net_interrupt, 0, dev->name, dev);
        if (ret) {
                printk ("  AT1700 at %#3x is unusable due to a conflict on"
                                "IRQ %d.\n", ioaddr, irq);
                goto err_out_priv;
        }

        return 0;

err_out_priv:
        kfree(dev->priv);
        dev->priv = NULL;
err_out:
#ifndef CONFIG_X86_PC9800
        release_region(ioaddr, AT1700_IO_EXTENT);
#else
        for (i = 0; i < 0x2000; i += 0x0200)
                release_region(ioaddr + i, 2);
#endif
        return ret;
}


/*  EEPROM_Ctrl bits. */
#define EE_SHIFT_CLK    0x40    /* EEPROM shift clock, in reg. 16. */
#define EE_CS                   0x20    /* EEPROM chip select, in reg. 16. */
#define EE_DATA_WRITE   0x80    /* EEPROM chip data in, in reg. 17. */
#define EE_DATA_READ    0x80    /* EEPROM chip data out, in reg. 17. */

/* Delay between EEPROM clock transitions. */
#ifndef CONFIG_X86_PC9800
#define eeprom_delay()  do { } while (0)
#else
#define eeprom_delay()  __asm__ ("out%B0 %%al,%0" :: "N"(0x5f))
#endif

/* The EEPROM commands include the alway-set leading bit. */
#define EE_WRITE_CMD    (5 << 6)
#define EE_READ_CMD             (6 << 6)
#define EE_ERASE_CMD    (7 << 6)

static int __init read_eeprom(long ioaddr, int location)
{
        int i;
        unsigned short retval = 0;
        long ee_addr = ioaddr + EEPROM_Ctrl;
        long ee_daddr = ioaddr + EEPROM_Data;
        int read_cmd = location | EE_READ_CMD;

        /* Shift the read command bits out. */
        for (i = 9; i >= 0; i--) {
                short dataval = (read_cmd & (1 << i)) ? EE_DATA_WRITE : 0;
                outb(EE_CS, ee_addr);
                outb(dataval, ee_daddr);
                eeprom_delay();
                outb(EE_CS | EE_SHIFT_CLK, ee_addr);    /* EEPROM clock tick. */
                eeprom_delay();
        }
        outb(EE_DATA_WRITE, ee_daddr);
        for (i = 16; i > 0; i--) {
                outb(EE_CS, ee_addr);
                eeprom_delay();
                outb(EE_CS | EE_SHIFT_CLK, ee_addr);
                eeprom_delay();
                retval = (retval << 1) | ((inb(ee_daddr) & EE_DATA_READ) ? 1 : 0);
        }

        /* Terminate the EEPROM access. */
        outb(EE_CS, ee_addr);
        eeprom_delay();
        outb(EE_SHIFT_CLK, ee_addr);
        outb(0, ee_addr);
        return retval;
}



static int net_open(struct net_device *dev)
{
        struct net_local *lp = (struct net_local *)dev->priv;
        int ioaddr = dev->base_addr;

        /* Set the configuration register 0 to 32K 100ns. byte-wide memory, 16 bit
           bus access, and two 4K Tx queues. */
        outb(0x5a, ioaddr + CONFIG_0);

        /* Powerup, switch to register bank 2, and enable the Rx and Tx. */
        outb(0xe8, ioaddr + CONFIG_1);

        lp->tx_started = 0;
        lp->tx_queue_ready = 1;
        lp->rx_started = 0;
        lp->tx_queue = 0;
        lp->tx_queue_len = 0;

        /* Turn on hardware Tx and Rx interrupts. */
        outb(0x82, ioaddr + TX_INTR);
        outb(0x81, ioaddr + RX_INTR);

        /* Enable the IRQ on boards of fmv18x it is feasible. */
        if (lp->jumpered) {
                outb(0x80, ioaddr + IOCONFIG1);
        }

        netif_start_queue(dev);
        return 0;
}

static void net_tx_timeout (struct net_device *dev)
{
        struct net_local *lp = (struct net_local *)dev->priv;
        int ioaddr = dev->base_addr;

        printk ("%s: transmit timed out with status %04x, %s?\n", dev->name,
                inw (ioaddr + STATUS), inb (ioaddr + TX_STATUS) & 0x80
                ? "IRQ conflict" : "network cable problem");
        printk ("%s: timeout registers: %04x %04x %04x %04x %04x %04x %04x %04x.\n",
         dev->name, inw(ioaddr + TX_STATUS), inw(ioaddr + TX_INTR), inw(ioaddr + TX_MODE),
                inw(ioaddr + CONFIG_0), inw(ioaddr + DATAPORT), inw(ioaddr + TX_START),
                inw(ioaddr + MODE13 - 1), inw(ioaddr + RX_CTRL));
        lp->stats.tx_errors++;
        /* ToDo: We should try to restart the adaptor... */
        outw(0xffff, ioaddr + MODE24);
        outw (0xffff, ioaddr + TX_STATUS);
        outb (0x5a, ioaddr + CONFIG_0);
        outb (0xe8, ioaddr + CONFIG_1);
        outw (0x8182, ioaddr + TX_INTR);
        outb (0x00, ioaddr + TX_START);
        outb (0x03, ioaddr + COL16CNTL);

        dev->trans_start = jiffies;

        lp->tx_started = 0;
        lp->tx_queue_ready = 1;
        lp->rx_started = 0;
        lp->tx_queue = 0;
        lp->tx_queue_len = 0;

        netif_wake_queue(dev);
}


static int net_send_packet (struct sk_buff *skb, struct net_device *dev)
{
        struct net_local *lp = (struct net_local *) dev->priv;
        int ioaddr = dev->base_addr;
        short length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
        short len = skb->len;
        unsigned char *buf = skb->data;
        static u8 pad[ETH_ZLEN];

        netif_stop_queue (dev);

        /* We may not start transmitting unless we finish transferring
           a packet into the Tx queue. During executing the following
           codes we possibly catch a Tx interrupt. Thus we flag off
           tx_queue_ready, so that we prevent the interrupt routine
           (net_interrupt) to start transmitting. */
        lp->tx_queue_ready = 0;
        {
                outw (length, ioaddr + DATAPORT);
                /* Packet data */
                outsw (ioaddr + DATAPORT, buf, len >> 1);
                /* Check for dribble byte */
                if (len & 1) {
                        outw(skb->data[skb->len-1], ioaddr + DATAPORT);
                        len++;
                }
                /* Check for packet padding */
                if (length != skb->len)
                        outsw(ioaddr + DATAPORT, pad, (length - len + 1) >> 1);

                lp->tx_queue++;
                lp->tx_queue_len += length + 2;
        }
        lp->tx_queue_ready = 1;

        if (lp->tx_started == 0) {
                /* If the Tx is idle, always trigger a transmit. */
                outb (0x80 | lp->tx_queue, ioaddr + TX_START);
                lp->tx_queue = 0;
                lp->tx_queue_len = 0;
                dev->trans_start = jiffies;
                lp->tx_started = 1;
                netif_start_queue (dev);
        } else if (lp->tx_queue_len < 4096 - 1502)
                /* Yes, there is room for one more packet. */
                netif_start_queue (dev);
        dev_kfree_skb (skb);

        return 0;
}

/* The typical workload of the driver:
   Handle the network interface interrupts. */
static irqreturn_t
net_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
        struct net_device *dev = dev_id;
        struct net_local *lp;
        int ioaddr, status;
        int handled = 0;

        if (dev == NULL) {
                printk ("at1700_interrupt(): irq %d for unknown device.\n", irq);
                return IRQ_NONE;
        }

        ioaddr = dev->base_addr;
        lp = (struct net_local *)dev->priv;
        
        spin_lock (&lp->lock);
        
        status = inw(ioaddr + TX_STATUS);
        outw(status, ioaddr + TX_STATUS);

        if (net_debug > 4)
                printk("%s: Interrupt with status %04x.\n", dev->name, status);
        if (lp->rx_started == 0 &&
            (status & 0xff00 || (inb(ioaddr + RX_MODE) & 0x40) == 0)) {
                /* Got a packet(s).
                   We cannot execute net_rx more than once at the same time for
                   the same device. During executing net_rx, we possibly catch a
                   Tx interrupt. Thus we flag on rx_started, so that we prevent
                   the interrupt routine (net_interrupt) to dive into net_rx
                   again. */
                handled = 1;
                lp->rx_started = 1;
                outb(0x00, ioaddr + RX_INTR);   /* Disable RX intr. */
                net_rx(dev);
                outb(0x81, ioaddr + RX_INTR);   /* Enable  RX intr. */
                lp->rx_started = 0;
        }
        if (status & 0x00ff) {
                handled = 1;
                if (status & 0x02) {
                        /* More than 16 collisions occurred */
                        if (net_debug > 4)
                                printk("%s: 16 Collision occur during Txing.\n", dev->name);
                        /* Cancel sending a packet. */
                        outb(0x03, ioaddr + COL16CNTL);
                        lp->stats.collisions++;
                }
                if (status & 0x82) {
                        lp->stats.tx_packets++;
                        /* The Tx queue has any packets and is not being
                           transferred a packet from the host, start
                           transmitting. */
                        if (lp->tx_queue && lp->tx_queue_ready) {
                                outb(0x80 | lp->tx_queue, ioaddr + TX_START);
                                lp->tx_queue = 0;
                                lp->tx_queue_len = 0;
                                dev->trans_start = jiffies;
                                netif_wake_queue (dev);
                        } else {
                                lp->tx_started = 0;
                                netif_wake_queue (dev);
                        }
                }
        }

        spin_unlock (&lp->lock);
        return IRQ_RETVAL(handled);
}

/* We have a good packet(s), get it/them out of the buffers. */
static void
net_rx(struct net_device *dev)
{
        struct net_local *lp = (struct net_local *)dev->priv;
        int ioaddr = dev->base_addr;
        int boguscount = 5;

        while ((inb(ioaddr + RX_MODE) & 0x40) == 0) {
                ushort status = inw(ioaddr + DATAPORT);
                ushort pkt_len = inw(ioaddr + DATAPORT);

                if (net_debug > 4)
                        printk("%s: Rxing packet mode %02x status %04x.\n",
                                   dev->name, inb(ioaddr + RX_MODE), status);
#ifndef final_version
                if (status == 0) {
                        outb(0x05, ioaddr + RX_CTRL);
                        break;
                }
#endif

                if ((status & 0xF0) != 0x20) {  /* There was an error. */
                        lp->stats.rx_errors++;
                        if (status & 0x08) lp->stats.rx_length_errors++;
                        if (status & 0x04) lp->stats.rx_frame_errors++;
                        if (status & 0x02) lp->stats.rx_crc_errors++;
                        if (status & 0x01) lp->stats.rx_over_errors++;
                } else {
                        /* Malloc up new buffer. */
                        struct sk_buff *skb;

                        if (pkt_len > 1550) {
                                printk("%s: The AT1700 claimed a very large packet, size %d.\n",
                                           dev->name, pkt_len);
                                /* Prime the FIFO and then flush the packet. */
                                inw(ioaddr + DATAPORT); inw(ioaddr + DATAPORT);
                                outb(0x05, ioaddr + RX_CTRL);
                                lp->stats.rx_errors++;
                                break;
                        }
                        skb = dev_alloc_skb(pkt_len+3);
                        if (skb == NULL) {
                                printk("%s: Memory squeeze, dropping packet (len %d).\n",
                                           dev->name, pkt_len);
                                /* Prime the FIFO and then flush the packet. */
                                inw(ioaddr + DATAPORT); inw(ioaddr + DATAPORT);
                                outb(0x05, ioaddr + RX_CTRL);
                                lp->stats.rx_dropped++;
                                break;
                        }
                        skb->dev = dev;
                        skb_reserve(skb,2);

                        insw(ioaddr + DATAPORT, skb_put(skb,pkt_len), (pkt_len + 1) >> 1);
                        skb->protocol=eth_type_trans(skb, dev);
                        netif_rx(skb);
                        dev->last_rx = jiffies;
                        lp->stats.rx_packets++;
                        lp->stats.rx_bytes += pkt_len;
                }
                if (--boguscount <= 0)
                        break;
        }

        /* If any worth-while packets have been received, dev_rint()
           has done a mark_bh(NET_BH) for us and will work on them
           when we get to the bottom-half routine. */
        {
                int i;
                for (i = 0; i < 20; i++) {
                        if ((inb(ioaddr + RX_MODE) & 0x40) == 0x40)
                                break;
                        inw(ioaddr + DATAPORT);                         /* dummy status read */
                        outb(0x05, ioaddr + RX_CTRL);
                }

                if (net_debug > 5)
                        printk("%s: Exint Rx packet with mode %02x after %d ticks.\n",
                                   dev->name, inb(ioaddr + RX_MODE), i);
        }
        return;
}

/* The inverse routine to net_open(). */
static int net_close(struct net_device *dev)
{
        struct net_local *lp = (struct net_local *)dev->priv;
        int ioaddr = dev->base_addr;

        netif_stop_queue(dev);

        /* Set configuration register 0 to disable Tx and Rx. */
        outb(0xda, ioaddr + CONFIG_0);

        /* No statistic counters on the chip to update. */

        /* Disable the IRQ on boards of fmv18x where it is feasible. */
        if (lp->jumpered) {
                outb(0x00, ioaddr + IOCONFIG1);
                free_irq(dev->irq, dev);
        }

        /* Power-down the chip.  Green, green, green! */
        outb(0x00, ioaddr + CONFIG_1);
        return 0;
}

/* Get the current statistics.
   This may be called with the card open or closed.
   There are no on-chip counters, so this function is trivial.
*/
static struct net_device_stats *
net_get_stats(struct net_device *dev)
{
        struct net_local *lp = (struct net_local *)dev->priv;
        return &lp->stats;
}

/*
  Set the multicast/promiscuous mode for this adaptor.
*/

static void
set_rx_mode(struct net_device *dev)
{
        int ioaddr = dev->base_addr;
        struct net_local *lp = (struct net_local *)dev->priv;
        unsigned char mc_filter[8];              /* Multicast hash filter */
        unsigned long flags;
        int i;

        if (dev->flags & IFF_PROMISC) {
                /* Unconditionally log net taps. */
                printk("%s: Promiscuous mode enabled.\n", dev->name);
                memset(mc_filter, 0xff, sizeof(mc_filter));
                outb(3, ioaddr + RX_MODE);      /* Enable promiscuous mode */
        } else if (dev->mc_count > MC_FILTERBREAK
                           ||  (dev->flags & IFF_ALLMULTI)) {
                /* Too many to filter perfectly -- accept all multicasts. */
                memset(mc_filter, 0xff, sizeof(mc_filter));
                outb(2, ioaddr + RX_MODE);      /* Use normal mode. */
        } else if (dev->mc_count == 0) {
                memset(mc_filter, 0x00, sizeof(mc_filter));
                outb(1, ioaddr + RX_MODE);      /* Ignore almost all multicasts. */
        } else {
                struct dev_mc_list *mclist;
                int i;

                memset(mc_filter, 0, sizeof(mc_filter));
                for (i = 0, mclist = dev->mc_list; mclist && i < dev->mc_count;
                         i++, mclist = mclist->next) {
                        unsigned int bit =
                                ether_crc_le(ETH_ALEN, mclist->dmi_addr) >> 26;
                        mc_filter[bit >> 3] |= (1 << bit);
                }
                outb(0x02, ioaddr + RX_MODE);   /* Use normal mode. */
        }

        spin_lock_irqsave (&lp->lock, flags);
        if (memcmp(mc_filter, lp->mc_filter, sizeof(mc_filter))) {
                int saved_bank = inw(ioaddr + CONFIG_0);
                /* Switch to bank 1 and set the multicast table. */
                outw((saved_bank & ~0x0C00) | 0x0480, ioaddr + CONFIG_0);
                for (i = 0; i < 8; i++)
                        outb(mc_filter[i], ioaddr + PORT_OFFSET(8 + i));
                memcpy(lp->mc_filter, mc_filter, sizeof(mc_filter));
                outw(saved_bank, ioaddr + CONFIG_0);
        }
        spin_unlock_irqrestore (&lp->lock, flags);
        return;
}

#ifdef MODULE
static struct net_device dev_at1700;
#ifndef CONFIG_X86_PC9800
static int io = 0x260;
#else
static int io = 0xd0;
#endif

static int irq;

MODULE_PARM(io, "i");
MODULE_PARM(irq, "i");
MODULE_PARM(net_debug, "i");
MODULE_PARM_DESC(io, "AT1700/FMV18X I/O base address");
MODULE_PARM_DESC(irq, "AT1700/FMV18X IRQ number");
MODULE_PARM_DESC(net_debug, "AT1700/FMV18X debug level (0-6)");

int init_module(void)
{
        if (io == 0)
                printk("at1700: You should not use auto-probing with insmod!\n");
        dev_at1700.base_addr = io;
        dev_at1700.irq       = irq;
        dev_at1700.init      = at1700_probe;
        if (register_netdev(&dev_at1700) != 0) {
                printk("at1700: register_netdev() returned non-zero.\n");
                return -EIO;
        }
        return 0;
}

void
cleanup_module(void)
{
#ifdef CONFIG_MCA       
        struct net_local *lp = dev_at1700.priv;
        if(lp->mca_slot)
        {
                mca_mark_as_unused(lp->mca_slot);
        }
#endif  
        unregister_netdev(&dev_at1700);
        kfree(dev_at1700.priv);
        dev_at1700.priv = NULL;

        /* If we don't do this, we can't re-insmod it later. */
        free_irq(dev_at1700.irq, NULL);
#ifndef CONFIG_X86_PC9800
        release_region(dev_at1700.base_addr, AT1700_IO_EXTENT);
#else
        {
                int i;
                for (i = 0; i < 0x2000; i += 0x200)
                        release_region(dev_at1700.base_addr + i, 2);
        }
#endif
}
#endif /* MODULE */
MODULE_LICENSE("GPL");


/*
 * Local variables:
 *  compile-command: "gcc -DMODULE -D__KERNEL__ -Wall -Wstrict-prototypes -O6 -c at1700.c"
 *  alt-compile-command: "gcc -DMODVERSIONS -DMODULE -D__KERNEL__ -Wall -Wstrict-prototypes -O6 -c at1700.c"
 *  tab-width: 4
 *  c-basic-offset: 4
 *  c-indent-level: 4
 * End:
 */