Subversion Repositories or1k

/* skeleton.c: A network driver outline for linux.

 *

 *      Written 1993-94 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 Public License, incorporated herein by reference.

 *

 *      The author may be reached as becker@CESDIS.gsfc.nasa.gov, or C/O

 *      Center of Excellence in Space Data and Information Sciences

 *         Code 930.5, Goddard Space Flight Center, Greenbelt MD 20771

 *

 *      This file is an outline for writing a network device driver for the

 *      the Linux operating system.

 *

 *      To write (or understand) a driver, have a look at the "loopback.c" file to

 *      get a feel of what is going on, and then use the code below as a skeleton

 *      for the new driver.

 *

 */

static const char *version =

        "skeleton.c:v1.51 9/24/94 Donald Becker (becker@cesdis.gsfc.nasa.gov)\n";

/*

 *  Sources:

 *      List your sources of programming information to document that

 *      the driver is your own creation, and give due credit to others

 *      that contributed to the work. Remember that GNU project code

 *      cannot use proprietary or trade secret information. Interface

 *      definitions are generally considered non-copyrightable to the

 *      extent that the same names and structures must be used to be

 *      compatible.

 *

 *      Finally, keep in mind that the Linux kernel is has an API, not

 *      ABI. Proprietary object-code-only distributions are not permitted

 *      under the GPL.

 */

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/sched.h>

#include <linux/types.h>

#include <linux/fcntl.h>

#include <linux/interrupt.h>

#include <linux/ptrace.h>

#include <linux/ioport.h>

#include <linux/in.h>

#include <linux/malloc.h>

#include <linux/string.h>

#include <asm/system.h>

#include <asm/bitops.h>

#include <asm/io.h>

#include <asm/dma.h>

#include <linux/errno.h>

#include <linux/netdevice.h>

#include <linux/etherdevice.h>

#include <linux/skbuff.h>

/*

 * The name of the card. Is used for messages and in the requests for

 * io regions, irqs and dma channels

 */

static const char* cardname = "netcard";

/* First, a few definitions that the brave might change. */

/* A zero-terminated list of I/O addresses to be probed. */

static unsigned int netcard_portlist[] =

   { 0x200, 0x240, 0x280, 0x2C0, 0x300, 0x320, 0x340, 0};

/* use 0 for production, 1 for verification, >2 for debug */

#ifndef NET_DEBUG

#define NET_DEBUG 2

#endif

static unsigned int net_debug = NET_DEBUG;

/* The number of low I/O ports used by the ethercard. */

#define NETCARD_IO_EXTENT       32

/* Information that need to be kept for each board. */

struct net_local {

        struct enet_statistics stats;

        long open_time;                 /* Useless example local info. */

};

/* The station (ethernet) address prefix, used for IDing the board. */

#define SA_ADDR0 0x00

#define SA_ADDR1 0x42

#define SA_ADDR2 0x65

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

extern int netcard_probe(struct device *dev);

static int netcard_probe1(struct device *dev, int ioaddr);

static int net_open(struct device *dev);

static int      net_send_packet(struct sk_buff *skb, struct device *dev);

static void net_interrupt(int irq, void *dev_id, struct pt_regs *regs);

static void net_rx(struct device *dev);

static int net_close(struct device *dev);

static struct enet_statistics *net_get_stats(struct device *dev);

static void set_multicast_list(struct device *dev);

/* Example routines you must write ;->. */

#define tx_done(dev) 1

extern void     hardware_send_packet(short ioaddr, char *buf, int length);

extern void chipset_init(struct device *dev, int startp);

/*

 * 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).

 */

#ifdef HAVE_DEVLIST

/*

 * Support for a alternate probe manager,

 * which will eliminate the boilerplate below.

 */

struct netdev_entry netcard_drv =

{cardname, netcard_probe1, NETCARD_IO_EXTENT, netcard_portlist};

#else

int

netcard_probe(struct device *dev)

{

        int i;

        int base_addr = dev ? dev->base_addr : 0;

        if (base_addr > 0x1ff)    /* Check a single specified location. */

                return netcard_probe1(dev, base_addr);

        else if (base_addr != 0)  /* Don't probe at all. */

                return -ENXIO;

        for (i = 0; netcard_portlist[i]; i++) {

                int ioaddr = netcard_portlist[i];

                if (check_region(ioaddr, NETCARD_IO_EXTENT))

                        continue;

                if (netcard_probe1(dev, ioaddr) == 0)

                        return 0;

        }

        return -ENODEV;

}

#endif

/*

 * This is the real probe routine. Linux has a history of friendly device

 * probes on the ISA bus. A good device probes avoids doing writes, and

 * verifies that the correct device exists and functions.

 */

static int netcard_probe1(struct device *dev, int ioaddr)

{

        static unsigned version_printed = 0;

        int i;

        /*

         * For ethernet adaptors the first three octets of the station address

         * contains the manufacturer's unique code. That might be a good probe

         * method. Ideally you would add additional checks.

         */

        if (inb(ioaddr + 0) != SA_ADDR0

                ||       inb(ioaddr + 1) != SA_ADDR1

                ||       inb(ioaddr + 2) != SA_ADDR2) {

                return -ENODEV;

        }

        /* Allocate a new 'dev' if needed. */

        if (dev == NULL) {

                /*

                 * Don't allocate the private data here, it is done later

                 * This makes it easier to free the memory when this driver

                 * is used as a module.

                 */

                dev = init_etherdev(0, 0);

                if (dev == NULL)

                        return -ENOMEM;

        }

        if (net_debug  &&  version_printed++ == 0)

                printk(KERN_DEBUG "%s", version);

        printk(KERN_INFO "%s: %s found at %#3x, ", dev->name, cardname, ioaddr);

        /* Fill in the 'dev' fields. */

        dev->base_addr = ioaddr;

        /* Retrieve and print the ethernet address. */

        for (i = 0; i < 6; i++)

                printk(" %2.2x", dev->dev_addr[i] = inb(ioaddr + i));

#ifdef jumpered_interrupts

        /*

         * If this board has jumpered interrupts, allocate the interrupt

         * vector now. There is no point in waiting since no other device

         * can use the interrupt, and this marks the irq as busy. Jumpered

         * interrupts are typically not reported by the boards, and we must

         * used autoIRQ to find them.

         */

        if (dev->irq == -1)

                ;       /* Do nothing: a user-level program will set it. */

        else if (dev->irq < 2) {        /* "Auto-IRQ" */

                autoirq_setup(0);

                /* Trigger an interrupt here. */

                dev->irq = autoirq_report(0);

                if (net_debug >= 2)

                        printk(" autoirq is %d", dev->irq);

        } else if (dev->irq == 2)

                /*

                 * Fixup for users that don't know that IRQ 2 is really

                 * IRQ9, or don't know which one to set.

                 */

                dev->irq = 9;

        {

                int irqval = request_irq(dev->irq, &net_interrupt, 0, cardname, NULL);

                if (irqval) {

                        printk("%s: unable to get IRQ %d (irqval=%d).\n",

                                   dev->name, dev->irq, irqval);

                        return -EAGAIN;

                }

        }

#endif  /* jumpered interrupt */

#ifdef jumpered_dma

        /*

         * If we use a jumpered DMA channel, that should be probed for and

         * allocated here as well. See lance.c for an example.

         */

        if (dev->dma == 0) {

                if (request_dma(dev->dma, cardname)) {

                        printk("DMA %d allocation failed.\n", dev->dma);

                        return -EAGAIN;

                } else

                        printk(", assigned DMA %d.\n", dev->dma);

        } else {

                short dma_status, new_dma_status;

                /* Read the DMA channel status registers. */

                dma_status = ((inb(DMA1_STAT_REG) >> 4) & 0x0f) |

                        (inb(DMA2_STAT_REG) & 0xf0);

                /* Trigger a DMA request, perhaps pause a bit. */

                outw(0x1234, ioaddr + 8);

                /* Re-read the DMA status registers. */

                new_dma_status = ((inb(DMA1_STAT_REG) >> 4) & 0x0f) |

                        (inb(DMA2_STAT_REG) & 0xf0);

                /*

                 * Eliminate the old and floating requests,

                 * and DMA4 the cascade.

                 */

                new_dma_status ^= dma_status;

                new_dma_status &= ~0x10;

                for (i = 7; i > 0; i--)

                        if (test_bit(i, &new_dma_status)) {

                                dev->dma = i;

                                break;

                        }

                if (i <= 0) {

                        printk("DMA probe failed.\n");

                        return -EAGAIN;

                }

                if (request_dma(dev->dma, cardname)) {

                        printk("probed DMA %d allocation failed.\n", dev->dma);

                        return -EAGAIN;

                }

        }

#endif  /* jumpered DMA */

        /* Initialize the device structure. */

        if (dev->priv == NULL) {

                dev->priv = kmalloc(sizeof(struct net_local), GFP_KERNEL);

                if (dev->priv == NULL)

                        return -ENOMEM;

        }

        memset(dev->priv, 0, sizeof(struct net_local));

        /* Grab the region so that no one else tries to probe our ioports. */

        request_region(ioaddr, NETCARD_IO_EXTENT, cardname);

        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_multicast_list;

        /* Fill in the fields of the device structure with ethernet values. */

        ether_setup(dev);

        return 0;

}

/*

 * Open/initialize the board. This is called (in the current kernel)

 * sometime after booting when the 'ifconfig' program is run.

 *

 * 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 non-reboot way to recover if something goes wrong.

 */

static int

net_open(struct device *dev)

{

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

        int ioaddr = dev->base_addr;

        /*

         * This is used if the interrupt line can turned off (shared).

         * See 3c503.c for an example of selecting the IRQ at config-time.

         */

        if (request_irq(dev->irq, &net_interrupt, 0, cardname, NULL)) {

                return -EAGAIN;

        }

        /*

         * Always allocate the DMA channel after the IRQ,

         * and clean up on failure.

         */

        if (request_dma(dev->dma, cardname)) {

                free_irq(dev->irq, NULL);

                return -EAGAIN;

        }

        irq2dev_map[dev->irq] = dev;

        /* Reset the hardware here. Don't forget to set the station address. */

        /*chipset_init(dev, 1);*/

        outb(0x00, ioaddr);

        lp->open_time = jiffies;

        dev->tbusy = 0;

        dev->interrupt = 0;

        dev->start = 1;

        MOD_INC_USE_COUNT;

        return 0;

}

static int

net_send_packet(struct sk_buff *skb, struct device *dev)

{

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

        int ioaddr = dev->base_addr;

        if (dev->tbusy) {

                /*

                 * If we get here, some higher level has decided we are broken.

                 * There should really be a "kick me" function call instead.

                 */

                int tickssofar = jiffies - dev->trans_start;

                if (tickssofar < 5)

                        return 1;

                printk(KERN_WARNING "%s: transmit timed out, %s?\n", dev->name,

                           tx_done(dev) ? "IRQ conflict" : "network cable problem");

                /* Try to restart the adaptor. */

                chipset_init(dev, 1);

                dev->tbusy=0;

                dev->trans_start = jiffies;

        }

        /*

         * Block a timer-based transmit from overlapping. This could better be

         * done with atomic_swap(1, dev->tbusy), but set_bit() works as well.

         */

        if (set_bit(0, (void*)&dev->tbusy) != 0)

                printk(KERN_WARNING "%s: Transmitter access conflict.\n", dev->name);

        else {

                short length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;

                unsigned char *buf = skb->data;

                hardware_send_packet(ioaddr, buf, length);

                dev->trans_start = jiffies;

        }

        dev_kfree_skb (skb, FREE_WRITE);

        /* You might need to clean up and record Tx statistics here. */

        if (inw(ioaddr) == /*RU*/81)

                lp->stats.tx_aborted_errors++;

        return 0;

}

/*

 * The typical workload of the driver:

 *   Handle the network interface interrupts.

 */

static void

net_interrupt(int irq, void *dev_id, struct pt_regs * regs)

{

        struct device *dev = (struct device *)(irq2dev_map[irq]);

        struct net_local *lp;

        int ioaddr, status, boguscount = 0;

        if (dev == NULL) {

                printk(KERN_WARNING "%s: irq %d for unknown device.\n", cardname, irq);

                return;

        }

        dev->interrupt = 1;

        ioaddr = dev->base_addr;

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

        status = inw(ioaddr + 0);

        do {

                if (status /*& RX_INTR*/) {

                        /* Got a packet(s). */

                        net_rx(dev);

                }

                if (status /*& TX_INTR*/) {

                        lp->stats.tx_packets++;

                        dev->tbusy = 0;

                        mark_bh(NET_BH);        /* Inform upper layers. */

                }

                if (status /*& COUNTERS_INTR*/) {

                        /* Increment the appropriate 'localstats' field. */

                        lp->stats.tx_window_errors++;

                }

        } while (++boguscount < 20) ;

        dev->interrupt = 0;

        return;

}

/* We have a good packet(s), get it/them out of the buffers. */

static void

net_rx(struct device *dev)

{

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

        int ioaddr = dev->base_addr;

        int boguscount = 10;

        do {

                int status = inw(ioaddr);

                int pkt_len = inw(ioaddr);

                if (pkt_len == 0)                /* Read all the frames? */

                        break;                  /* Done for now */

                if (status & 0x40) {    /* There was an error. */

                        lp->stats.rx_errors++;

                        if (status & 0x20) lp->stats.rx_frame_errors++;

                        if (status & 0x10) lp->stats.rx_over_errors++;

                        if (status & 0x08) lp->stats.rx_crc_errors++;

                        if (status & 0x04) lp->stats.rx_fifo_errors++;

                } else {

                        /* Malloc up new buffer. */

                        struct sk_buff *skb;

                        skb = dev_alloc_skb(pkt_len);

                        if (skb == NULL) {

                                printk(KERN_NOTICE "%s: Memory squeeze, dropping packet.\n",

                                           dev->name);

                                lp->stats.rx_dropped++;

                                break;

                        }

                        skb->dev = dev;

                        /* 'skb->data' points to the start of sk_buff data area. */

                        memcpy(skb_put(skb,pkt_len), (void*)dev->rmem_start,

                                   pkt_len);

                        /* or */

                        insw(ioaddr, skb->data, (pkt_len + 1) >> 1);

                        netif_rx(skb);

                        lp->stats.rx_packets++;

                }

        } while (--boguscount);

        /*

         * 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.

         */

        return;

}

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

static int

net_close(struct device *dev)

{

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

        int ioaddr = dev->base_addr;

        lp->open_time = 0;

        dev->tbusy = 1;

        dev->start = 0;

        /* Flush the Tx and disable Rx here. */

        disable_dma(dev->dma);

        /* If not IRQ or DMA jumpered, free up the line. */

        outw(0x00, ioaddr+0);    /* Release the physical interrupt line. */

        free_irq(dev->irq, NULL);

        free_dma(dev->dma);

        irq2dev_map[dev->irq] = 0;

        /* Update the statistics here. */

        MOD_DEC_USE_COUNT;

        return 0;

}

/*

 * Get the current statistics.

 * This may be called with the card open or closed.

 */

static struct enet_statistics *

net_get_stats(struct device *dev)

{

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

        short ioaddr = dev->base_addr;

        cli();

        /* Update the statistics from the device registers. */

        lp->stats.rx_missed_errors = inw(ioaddr+1);

        sti();

        return &lp->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 device *dev)

{

        short ioaddr = dev->base_addr;

        if (dev->flags&IFF_PROMISC)

        {

                /* Enable promiscuous mode */

                outw(MULTICAST|PROMISC, ioaddr);

        }

        else if((dev->flags&IFF_ALLMULTI) || dev->mc_count > HW_MAX_ADDRS)

        {

                /* Disable promiscuous mode, use normal mode. */

                hardware_set_filter(NULL);

                outw(MULTICAST, ioaddr);

        }

        else if(dev->mc_count)

        {

                /* Walk the address list, and load the filter */

                hardware_set_filter(dev->mc_list);

                outw(MULTICAST, ioaddr);

        }

        else

                outw(0, ioaddr);

}

#ifdef MODULE

static char devicename[9] = { 0, };

static struct device this_device = {

        devicename, /* will be inserted by linux/drivers/net/net_init.c */

        0, 0, 0, 0,

        0, 0,  /* I/O address, IRQ */

        0, 0, 0, NULL, netcard_probe };

static int io = 0x300;

static int irq = 0;

static int dma = 0;

static int mem = 0;

int init_module(void)

{

        int result;

        if (io == 0)

                printk(KERN_WARNING "%s: You shouldn't use auto-probing with insmod!\n",

                           cardname);

        /* Copy the parameters from insmod into the device structure. */

        this_device.base_addr = io;

        this_device.irq       = irq;

        this_device.dma       = dma;

        this_device.mem_start = mem;

        if ((result = register_netdev(&this_device)) != 0)

                return result;

        return 0;

}

void

cleanup_module(void)

{

        /* No need to check MOD_IN_USE, as sys_delete_module() checks. */

        unregister_netdev(&this_device);

        /*

         * If we don't do this, we can't re-insmod it later.

         * Release irq/dma here, when you have jumpered versions and

         * allocate them in net_probe1().

         */

        /*

           free_irq(this_device.irq, NULL);

           free_dma(this_device.dma);

        */

        release_region(this_device.base_addr, NETCARD_IO_EXTENT);

        if (this_device.priv)

                kfree_s(this_device.priv, sizeof(struct net_local));

}

#endif /* MODULE */

/*

 * Local variables:

 *  compile-command:

 *      gcc -D__KERNEL__ -Wall -Wstrict-prototypes -Wwrite-strings

 *      -Wredundant-decls -O2 -m486 -c skeleton.c

 *  version-control: t

 *  kept-new-versions: 5

 *  tab-width: 4

 *  c-indent-level: 4

 * End:

 */