/* 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;
}
/*
* If some higher layer thinks we've missed an tx-done interrupt
* we are passed NULL. Caution: dev_tint() handles the cli()/sti()
* itself.
*/
if (skb == NULL) {
dev_tint(dev);
return 0;
}
/*
* 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:
*/
