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/* isa-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 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 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 =
"isa-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/slab.h>
#include <linux/string.h>
#include <asm/system.h>
#include <asm/bitops.h>
#include <linux/spinlock.h>
#include <asm/io.h>
#include <asm/dma.h>
#include <linux/errno.h>
#include <linux/init.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[] __initdata =
{ 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
#define MY_TX_TIMEOUT ((400*HZ)/1000)
/* Information that need to be kept for each board. */
struct net_local {
struct net_device_stats stats;
long open_time; /* Useless example local info. */
/* Tx control lock. This protects the transmit buffer ring
* state along with the "tx full" state of the driver. This
* means all netif_queue flow control actions are protected
* by this lock as well.
*/
spinlock_t lock;
};
/* 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 net_device *dev);
static int netcard_probe1(struct net_device *dev, int ioaddr);
static int net_open(struct net_device *dev);
static int net_send_packet(struct sk_buff *skb, struct net_device *dev);
static void 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_multicast_list(struct net_device *dev);
static void net_tx_timeout(struct net_device *dev);
/* Example routines you must write ;->. */
#define tx_done(dev) 1
static void hardware_send_packet(short ioaddr, char *buf, int length);
static void chipset_init(struct net_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).
*/
int __init
netcard_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 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;
}
/*
* 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 __init netcard_probe1(struct net_device *dev, int ioaddr)
{
struct net_local *np;
static unsigned version_printed;
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;
}
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, dev);
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));
np = (struct net_local *)dev->priv;
spin_lock_init(&np->lock);
/* 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;
dev->tx_timeout = &net_tx_timeout;
dev->watchdog_timeo = MY_TX_TIMEOUT;
/* Fill in the fields of the device structure with ethernet values. */
ether_setup(dev);
return 0;
}
static void net_tx_timeout(struct net_device *dev)
{
struct net_local *np = (struct net_local *)dev->priv;
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);
np->stats.tx_errors++;
/* If we have space available to accept new transmit
* requests, wake up the queueing layer. This would
* be the case if the chipset_init() call above just
* flushes out the tx queue and empties it.
*
* If instead, the tx queue is retained then the
* netif_wake_queue() call should be placed in the
* TX completion interrupt handler of the driver instead
* of here.
*/
if (!tx_full(dev))
netif_wake_queue(dev);
}
/*
* 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 net_device *dev)
{
struct net_local *np = (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, dev)) {
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, dev);
return -EAGAIN;
}
/* Reset the hardware here. Don't forget to set the station address. */
chipset_init(dev, 1);
outb(0x00, ioaddr);
np->open_time = jiffies;
/* We are now ready to accept transmit requeusts from
* the queueing layer of the networking.
*/
netif_start_queue(dev);
return 0;
}
/* This will only be invoked if your driver is _not_ in XOFF state.
* What this means is that you need not check it, and that this
* invariant will hold if you make sure that the netif_*_queue()
* calls are done at the proper times.
*/
static int net_send_packet(struct sk_buff *skb, struct net_device *dev)
{
struct net_local *np = (struct net_local *)dev->priv;
int ioaddr = dev->base_addr;
short length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
unsigned char *buf = skb->data;
/* If some error occurs while trying to transmit this
* packet, you should return '1' from this function.
* In such a case you _may not_ do anything to the
* SKB, it is still owned by the network queueing
* layer when an error is returned. This means you
* may not modify any SKB fields, you may not free
* the SKB, etc.
*/
#if TX_RING
/* This is the most common case for modern hardware.
* The spinlock protects this code from the TX complete
* hardware interrupt handler. Queue flow control is
* thus managed under this lock as well.
*/
spin_lock_irq(&np->lock);
add_to_tx_ring(np, skb, length);
dev->trans_start = jiffies;
/* If we just used up the very last entry in the
* TX ring on this device, tell the queueing
* layer to send no more.
*/
if (tx_full(dev))
netif_stop_queue(dev);
/* When the TX completion hw interrupt arrives, this
* is when the transmit statistics are updated.
*/
spin_unlock_irq(&np->lock);
#else
/* This is the case for older hardware which takes
* a single transmit buffer at a time, and it is
* just written to the device via PIO.
*
* No spin locking is needed since there is no TX complete
* event. If by chance your card does have a TX complete
* hardware IRQ then you may need to utilize np->lock here.
*/
hardware_send_packet(ioaddr, buf, length);
np->stats.tx_bytes += skb->len;
dev->trans_start = jiffies;
/* You might need to clean up and record Tx statistics here. */
if (inw(ioaddr) == /*RU*/81)
np->stats.tx_aborted_errors++;
dev_kfree_skb (skb);
#endif
return 0;
}
#if TX_RING
/* This handles TX complete events posted by the device
* via interrupts.
*/
void net_tx(struct net_device *dev)
{
struct net_local *np = (struct net_local *)dev->priv;
int entry;
/* This protects us from concurrent execution of
* our dev->hard_start_xmit function above.
*/
spin_lock(&np->lock);
entry = np->tx_old;
while (tx_entry_is_sent(np, entry)) {
struct sk_buff *skb = np->skbs[entry];
np->stats.tx_bytes += skb->len;
dev_kfree_skb_irq (skb);
entry = next_tx_entry(np, entry);
}
np->tx_old = entry;
/* If we had stopped the queue due to a "tx full"
* condition, and space has now been made available,
* wake up the queue.
*/
if (netif_queue_stopped(dev) && ! tx_full(dev))
netif_wake_queue(dev);
spin_unlock(&np->lock);
}
#endif
/*
* 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 net_device *dev = dev_id;
struct net_local *np;
int ioaddr, status;
ioaddr = dev->base_addr;
np = (struct net_local *)dev->priv;
status = inw(ioaddr + 0);
if (status & RX_INTR) {
/* Got a packet(s). */
net_rx(dev);
}
#if TX_RING
if (status & TX_INTR) {
/* Transmit complete. */
net_tx(dev);
np->stats.tx_packets++;
netif_wake_queue(dev);
}
#endif
if (status & COUNTERS_INTR) {
/* Increment the appropriate 'localstats' field. */
np->stats.tx_window_errors++;
}
}
/* 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 = 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;
lp->stats.rx_bytes+=pkt_len;
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);
dev->last_rx = jiffies;
lp->stats.rx_packets++;
lp->stats.rx_bytes += pkt_len;
}
} while (--boguscount);
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;
lp->open_time = 0;
netif_stop_queue(dev);
/* 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, dev);
free_dma(dev->dma);
/* Update the statistics here. */
return 0;
}
/*
* Get the current statistics.
* This may be called with the card open or closed.
*/
static struct net_device_stats *net_get_stats(struct net_device *dev)
{
struct net_local *lp = (struct net_local *)dev->priv;
short ioaddr = dev->base_addr;
/* Update the statistics from the device registers. */
lp->stats.rx_missed_errors = inw(ioaddr+1);
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 net_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 struct net_device this_device;
static int io = 0x300;
static int irq;
static int dma;
static int mem;
MODULE_LICENSE("GPL");
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;
this_device.init = netcard_probe;
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, dev);
free_dma(this_device.dma);
*/
release_region(this_device.base_addr, NETCARD_IO_EXTENT);
if (this_device.priv)
kfree(this_device.priv);
}
#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:
*/
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