de600.c

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static const char version[] = "de600.c: $Revision: 1.41-2.5 $,  Bjorn Ekwall ([email protected])\n";
/*
 *  de600.c
 *
 *  Linux driver for the D-Link DE-600 Ethernet pocket adapter.
 *
 *  Portions (C) Copyright 1993, 1994 by Bjorn Ekwall
 *  The Author may be reached as [email protected]
 *
 *  Based on adapter information gathered from DE600.ASM by D-Link Inc.,
 *  as included on disk C in the v.2.11 of PC/TCP from FTP Software.
 *  For DE600.asm:
 *      Portions (C) Copyright 1990 D-Link, Inc.
 *      Copyright, 1988-1992, Russell Nelson, Crynwr Software
 *
 *  Adapted to the sample network driver core for linux,
 *  written by: Donald Becker <[email protected]>
 *      (Now at <[email protected]>)
 *
 **************************************************************/
/*
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 **************************************************************/

/* Add more time here if your adapter won't work OK: */
#define DE600_SLOW_DOWN udelay(delay_time)

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/string.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>

#include <asm/io.h>

#include "de600.h"

static bool check_lost = true;
module_param(check_lost, bool, 0);
MODULE_PARM_DESC(check_lost, "If set then check for unplugged de600");

static unsigned int delay_time = 10;
module_param(delay_time, int, 0);
MODULE_PARM_DESC(delay_time, "DE-600 deley on I/O in microseconds");


/*
 * D-Link driver variables:
 */

static volatile int     rx_page;

#define TX_PAGES 2
static volatile int     tx_fifo[TX_PAGES];
static volatile int     tx_fifo_in;
static volatile int     tx_fifo_out;
static volatile int     free_tx_pages = TX_PAGES;
static int          was_down;
static DEFINE_SPINLOCK(de600_lock);

static inline u8 de600_read_status(struct net_device *dev)
{
    u8 status;

    outb_p(STATUS, DATA_PORT);
    status = inb(STATUS_PORT);
    outb_p(NULL_COMMAND | HI_NIBBLE, DATA_PORT);

    return status;
}

static inline u8 de600_read_byte(unsigned char type, struct net_device *dev)
{
    /* dev used by macros */
    u8 lo;
    outb_p((type), DATA_PORT);
    lo = ((unsigned char)inb(STATUS_PORT)) >> 4;
    outb_p((type) | HI_NIBBLE, DATA_PORT);
    return ((unsigned char)inb(STATUS_PORT) & (unsigned char)0xf0) | lo;
}

/*
 * Open/initialize the board.  This is called (in the current kernel)
 * after booting when 'ifconfig <dev->name> $IP_ADDR' is run (in rc.inet1).
 *
 * This routine should set everything up anew at each open, even
 * registers that "should" only need to be set once at boot, so that
 * there is a non-reboot way to recover if something goes wrong.
 */

static int de600_open(struct net_device *dev)
{
    unsigned long flags;
    int ret = request_irq(DE600_IRQ, de600_interrupt, 0, dev->name, dev);
    if (ret) {
        printk(KERN_ERR "%s: unable to get IRQ %d\n", dev->name, DE600_IRQ);
        return ret;
    }
    spin_lock_irqsave(&de600_lock, flags);
    ret = adapter_init(dev);
    spin_unlock_irqrestore(&de600_lock, flags);
    return ret;
}

/*
 * The inverse routine to de600_open().
 */

static int de600_close(struct net_device *dev)
{
    select_nic();
    rx_page = 0;
    de600_put_command(RESET);
    de600_put_command(STOP_RESET);
    de600_put_command(0);
    select_prn();
    free_irq(DE600_IRQ, dev);
    return 0;
}

static inline void trigger_interrupt(struct net_device *dev)
{
    de600_put_command(FLIP_IRQ);
    select_prn();
    DE600_SLOW_DOWN;
    select_nic();
    de600_put_command(0);
}

/*
 * Copy a buffer to the adapter transmit page memory.
 * Start sending.
 */

static int de600_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
    unsigned long flags;
    int transmit_from;
    int len;
    int tickssofar;
    u8  *buffer = skb->data;
    int i;

    if (free_tx_pages <= 0) {   /* Do timeouts, to avoid hangs. */
        tickssofar = jiffies - dev_trans_start(dev);
        if (tickssofar < HZ/20)
            return NETDEV_TX_BUSY;
        /* else */
        printk(KERN_WARNING "%s: transmit timed out (%d), %s?\n", dev->name, tickssofar, "network cable problem");
        /* Restart the adapter. */
        spin_lock_irqsave(&de600_lock, flags);
        if (adapter_init(dev)) {
            spin_unlock_irqrestore(&de600_lock, flags);
            return NETDEV_TX_BUSY;
        }
        spin_unlock_irqrestore(&de600_lock, flags);
    }

    /* Start real output */
    pr_debug("de600_start_xmit:len=%d, page %d/%d\n", skb->len, tx_fifo_in, free_tx_pages);

    if ((len = skb->len) < RUNT)
        len = RUNT;

    spin_lock_irqsave(&de600_lock, flags);
    select_nic();
    tx_fifo[tx_fifo_in] = transmit_from = tx_page_adr(tx_fifo_in) - len;
    tx_fifo_in = (tx_fifo_in + 1) % TX_PAGES; /* Next free tx page */

    if(check_lost)
    {
        /* This costs about 40 instructions per packet... */
        de600_setup_address(NODE_ADDRESS, RW_ADDR);
        de600_read_byte(READ_DATA, dev);
        if (was_down || (de600_read_byte(READ_DATA, dev) != 0xde)) {
            if (adapter_init(dev)) {
                spin_unlock_irqrestore(&de600_lock, flags);
                return NETDEV_TX_BUSY;
            }
        }
    }

    de600_setup_address(transmit_from, RW_ADDR);
    for (i = 0;  i < skb->len ; ++i, ++buffer)
        de600_put_byte(*buffer);
    for (; i < len; ++i)
        de600_put_byte(0);

    if (free_tx_pages-- == TX_PAGES) { /* No transmission going on */
        dev->trans_start = jiffies;
        netif_start_queue(dev); /* allow more packets into adapter */
        /* Send page and generate a faked interrupt */
        de600_setup_address(transmit_from, TX_ADDR);
        de600_put_command(TX_ENABLE);
    }
    else {
        if (free_tx_pages)
            netif_start_queue(dev);
        else
            netif_stop_queue(dev);
        select_prn();
    }
    spin_unlock_irqrestore(&de600_lock, flags);
    dev_kfree_skb(skb);
    return NETDEV_TX_OK;
}

/*
 * The typical workload of the driver:
 * Handle the network interface interrupts.
 */

static irqreturn_t de600_interrupt(int irq, void *dev_id)
{
    struct net_device   *dev = dev_id;
    u8      irq_status;
    int     retrig = 0;
    int     boguscount = 0;

    spin_lock(&de600_lock);

    select_nic();
    irq_status = de600_read_status(dev);

    do {
        pr_debug("de600_interrupt (%02X)\n", irq_status);

        if (irq_status & RX_GOOD)
            de600_rx_intr(dev);
        else if (!(irq_status & RX_BUSY))
            de600_put_command(RX_ENABLE);

        /* Any transmission in progress? */
        if (free_tx_pages < TX_PAGES)
            retrig = de600_tx_intr(dev, irq_status);
        else
            retrig = 0;

        irq_status = de600_read_status(dev);
    } while ( (irq_status & RX_GOOD) || ((++boguscount < 100) && retrig) );
    /*
     * Yeah, it _looks_ like busy waiting, smells like busy waiting
     * and I know it's not PC, but please, it will only occur once
     * in a while and then only for a loop or so (< 1ms for sure!)
     */

    /* Enable adapter interrupts */
    select_prn();
    if (retrig)
        trigger_interrupt(dev);
    spin_unlock(&de600_lock);
    return IRQ_HANDLED;
}

static int de600_tx_intr(struct net_device *dev, int irq_status)
{
    /*
     * Returns 1 if tx still not done
     */

    /* Check if current transmission is done yet */
    if (irq_status & TX_BUSY)
        return 1; /* tx not done, try again */

    /* else */
    /* If last transmission OK then bump fifo index */
    if (!(irq_status & TX_FAILED16)) {
        tx_fifo_out = (tx_fifo_out + 1) % TX_PAGES;
        ++free_tx_pages;
        dev->stats.tx_packets++;
        netif_wake_queue(dev);
    }

    /* More to send, or resend last packet? */
    if ((free_tx_pages < TX_PAGES) || (irq_status & TX_FAILED16)) {
        dev->trans_start = jiffies;
        de600_setup_address(tx_fifo[tx_fifo_out], TX_ADDR);
        de600_put_command(TX_ENABLE);
        return 1;
    }
    /* else */

    return 0;
}

/*
 * We have a good packet, get it out of the adapter.
 */
static void de600_rx_intr(struct net_device *dev)
{
    struct sk_buff  *skb;
    int     i;
    int     read_from;
    int     size;
    unsigned char   *buffer;

    /* Get size of received packet */
    size = de600_read_byte(RX_LEN, dev);    /* low byte */
    size += (de600_read_byte(RX_LEN, dev) << 8);    /* high byte */
    size -= 4;  /* Ignore trailing 4 CRC-bytes */

    /* Tell adapter where to store next incoming packet, enable receiver */
    read_from = rx_page_adr();
    next_rx_page();
    de600_put_command(RX_ENABLE);

    if ((size < 32)  ||  (size > 1535)) {
        printk(KERN_WARNING "%s: Bogus packet size %d.\n", dev->name, size);
        if (size > 10000)
            adapter_init(dev);
        return;
    }

    skb = netdev_alloc_skb(dev, size + 2);
    if (skb == NULL) {
        printk("%s: Couldn't allocate a sk_buff of size %d.\n", dev->name, size);
        return;
    }
    /* else */

    skb_reserve(skb,2); /* Align */

    /* 'skb->data' points to the start of sk_buff data area. */
    buffer = skb_put(skb,size);

    /* copy the packet into the buffer */
    de600_setup_address(read_from, RW_ADDR);
    for (i = size; i > 0; --i, ++buffer)
        *buffer = de600_read_byte(READ_DATA, dev);

    skb->protocol=eth_type_trans(skb,dev);

    netif_rx(skb);

    /* update stats */
    dev->stats.rx_packets++; /* count all receives */
    dev->stats.rx_bytes += size; /* count all received bytes */

    /*
     * If any worth-while packets have been received, netif_rx()
     * will work on them when we get to the tasklets.
     */
}

static const struct net_device_ops de600_netdev_ops = {
    .ndo_open       = de600_open,
    .ndo_stop       = de600_close,
    .ndo_start_xmit     = de600_start_xmit,
    .ndo_change_mtu     = eth_change_mtu,
    .ndo_set_mac_address    = eth_mac_addr,
    .ndo_validate_addr  = eth_validate_addr,
};


static struct net_device * __init de600_probe(void)
{
    int i;
    struct net_device *dev;
    int err;

    dev = alloc_etherdev(0);
    if (!dev)
        return ERR_PTR(-ENOMEM);


    if (!request_region(DE600_IO, 3, "de600")) {
        printk(KERN_WARNING "DE600: port 0x%x busy\n", DE600_IO);
        err = -EBUSY;
        goto out;
    }

    printk(KERN_INFO "%s: D-Link DE-600 pocket adapter", dev->name);
    /* Alpha testers must have the version number to report bugs. */
    pr_debug("%s", version);

    /* probe for adapter */
    err = -ENODEV;
    rx_page = 0;
    select_nic();
    (void)de600_read_status(dev);
    de600_put_command(RESET);
    de600_put_command(STOP_RESET);
    if (de600_read_status(dev) & 0xf0) {
        printk(": not at I/O %#3x.\n", DATA_PORT);
        goto out1;
    }

    /*
     * Maybe we found one,
     * have to check if it is a D-Link DE-600 adapter...
     */

    /* Get the adapter ethernet address from the ROM */
    de600_setup_address(NODE_ADDRESS, RW_ADDR);
    for (i = 0; i < ETH_ALEN; i++) {
        dev->dev_addr[i] = de600_read_byte(READ_DATA, dev);
        dev->broadcast[i] = 0xff;
    }

    /* Check magic code */
    if ((dev->dev_addr[1] == 0xde) && (dev->dev_addr[2] == 0x15)) {
        /* OK, install real address */
        dev->dev_addr[0] = 0x00;
        dev->dev_addr[1] = 0x80;
        dev->dev_addr[2] = 0xc8;
        dev->dev_addr[3] &= 0x0f;
        dev->dev_addr[3] |= 0x70;
    } else {
        printk(" not identified in the printer port\n");
        goto out1;
    }

    printk(", Ethernet Address: %pM\n", dev->dev_addr);

    dev->netdev_ops = &de600_netdev_ops;

    dev->flags&=~IFF_MULTICAST;

    select_prn();

    err = register_netdev(dev);
    if (err)
        goto out1;

    return dev;

out1:
    release_region(DE600_IO, 3);
out:
    free_netdev(dev);
    return ERR_PTR(err);
}

static int adapter_init(struct net_device *dev)
{
    int i;

    select_nic();
    rx_page = 0; /* used by RESET */
    de600_put_command(RESET);
    de600_put_command(STOP_RESET);

    /* Check if it is still there... */
    /* Get the some bytes of the adapter ethernet address from the ROM */
    de600_setup_address(NODE_ADDRESS, RW_ADDR);
    de600_read_byte(READ_DATA, dev);
    if ((de600_read_byte(READ_DATA, dev) != 0xde) ||
        (de600_read_byte(READ_DATA, dev) != 0x15)) {
    /* was: if (de600_read_status(dev) & 0xf0) { */
        printk("Something has happened to the DE-600!  Please check it and do a new ifconfig!\n");
        /* Goodbye, cruel world... */
        dev->flags &= ~IFF_UP;
        de600_close(dev);
        was_down = 1;
        netif_stop_queue(dev); /* Transmit busy...  */
        return 1; /* failed */
    }

    if (was_down) {
        printk(KERN_INFO "%s: Thanks, I feel much better now!\n", dev->name);
        was_down = 0;
    }

    tx_fifo_in = 0;
    tx_fifo_out = 0;
    free_tx_pages = TX_PAGES;


    /* set the ether address. */
    de600_setup_address(NODE_ADDRESS, RW_ADDR);
    for (i = 0; i < ETH_ALEN; i++)
        de600_put_byte(dev->dev_addr[i]);

    /* where to start saving incoming packets */
    rx_page = RX_BP | RX_BASE_PAGE;
    de600_setup_address(MEM_4K, RW_ADDR);
    /* Enable receiver */
    de600_put_command(RX_ENABLE);
    select_prn();

    netif_start_queue(dev);

    return 0; /* OK */
}

static struct net_device *de600_dev;

static int __init de600_init(void)
{
    de600_dev = de600_probe();
    if (IS_ERR(de600_dev))
        return PTR_ERR(de600_dev);
    return 0;
}

static void __exit de600_exit(void)
{
    unregister_netdev(de600_dev);
    release_region(DE600_IO, 3);
    free_netdev(de600_dev);
}

module_init(de600_init);
module_exit(de600_exit);

MODULE_LICENSE("GPL");