1 /* isa-skeleton.c: A network driver outline for linux.
3 * Written 1993-94 by Donald Becker.
5 * Copyright 1993 United States Government as represented by the
6 * Director, National Security Agency.
8 * This software may be used and distributed according to the terms
9 * of the GNU General Public License, incorporated herein by reference.
11 * The author may be reached as becker@scyld.com, or C/O
12 * Scyld Computing Corporation
13 * 410 Severn Ave., Suite 210
16 * This file is an outline for writing a network device driver for the
17 * the Linux operating system.
19 * To write (or understand) a driver, have a look at the "loopback.c" file to
20 * get a feel of what is going on, and then use the code below as a skeleton
25 static const char *version
=
26 "isa-skeleton.c:v1.51 9/24/94 Donald Becker (becker@cesdis.gsfc.nasa.gov)\n";
30 * List your sources of programming information to document that
31 * the driver is your own creation, and give due credit to others
32 * that contributed to the work. Remember that GNU project code
33 * cannot use proprietary or trade secret information. Interface
34 * definitions are generally considered non-copyrightable to the
35 * extent that the same names and structures must be used to be
38 * Finally, keep in mind that the Linux kernel is has an API, not
39 * ABI. Proprietary object-code-only distributions are not permitted
43 #include <linux/module.h>
44 #include <linux/kernel.h>
45 #include <linux/types.h>
46 #include <linux/fcntl.h>
47 #include <linux/interrupt.h>
48 #include <linux/ioport.h>
50 #include <linux/slab.h>
51 #include <linux/string.h>
52 #include <linux/spinlock.h>
53 #include <linux/errno.h>
54 #include <linux/init.h>
55 #include <linux/netdevice.h>
56 #include <linux/etherdevice.h>
57 #include <linux/skbuff.h>
58 #include <linux/bitops.h>
60 #include <asm/system.h>
65 * The name of the card. Is used for messages and in the requests for
66 * io regions, irqs and dma channels
68 static const char* cardname
= "netcard";
70 /* First, a few definitions that the brave might change. */
72 /* A zero-terminated list of I/O addresses to be probed. */
73 static unsigned int netcard_portlist
[] __initdata
=
74 { 0x200, 0x240, 0x280, 0x2C0, 0x300, 0x320, 0x340, 0};
76 /* use 0 for production, 1 for verification, >2 for debug */
80 static unsigned int net_debug
= NET_DEBUG
;
82 /* The number of low I/O ports used by the ethercard. */
83 #define NETCARD_IO_EXTENT 32
85 #define MY_TX_TIMEOUT ((400*HZ)/1000)
87 /* Information that need to be kept for each board. */
89 struct net_device_stats stats
;
90 long open_time
; /* Useless example local info. */
92 /* Tx control lock. This protects the transmit buffer ring
93 * state along with the "tx full" state of the driver. This
94 * means all netif_queue flow control actions are protected
95 * by this lock as well.
100 /* The station (ethernet) address prefix, used for IDing the board. */
101 #define SA_ADDR0 0x00
102 #define SA_ADDR1 0x42
103 #define SA_ADDR2 0x65
105 /* Index to functions, as function prototypes. */
107 static int netcard_probe1(struct net_device
*dev
, int ioaddr
);
108 static int net_open(struct net_device
*dev
);
109 static int net_send_packet(struct sk_buff
*skb
, struct net_device
*dev
);
110 static irqreturn_t
net_interrupt(int irq
, void *dev_id
);
111 static void net_rx(struct net_device
*dev
);
112 static int net_close(struct net_device
*dev
);
113 static struct net_device_stats
*net_get_stats(struct net_device
*dev
);
114 static void set_multicast_list(struct net_device
*dev
);
115 static void net_tx_timeout(struct net_device
*dev
);
118 /* Example routines you must write ;->. */
119 #define tx_done(dev) 1
120 static void hardware_send_packet(short ioaddr
, char *buf
, int length
);
121 static void chipset_init(struct net_device
*dev
, int startp
);
124 * Check for a network adaptor of this type, and return '0' iff one exists.
125 * If dev->base_addr == 0, probe all likely locations.
126 * If dev->base_addr == 1, always return failure.
127 * If dev->base_addr == 2, allocate space for the device and return success
128 * (detachable devices only).
130 static int __init
do_netcard_probe(struct net_device
*dev
)
133 int base_addr
= dev
->base_addr
;
136 if (base_addr
> 0x1ff) /* Check a single specified location. */
137 return netcard_probe1(dev
, base_addr
);
138 else if (base_addr
!= 0) /* Don't probe at all. */
141 for (i
= 0; netcard_portlist
[i
]; i
++) {
142 int ioaddr
= netcard_portlist
[i
];
143 if (netcard_probe1(dev
, ioaddr
) == 0)
151 static void cleanup_card(struct net_device
*dev
)
156 #ifdef jumpered_interrupts
157 free_irq(dev
->irq
, dev
);
159 release_region(dev
->base_addr
, NETCARD_IO_EXTENT
);
163 struct net_device
* __init
netcard_probe(int unit
)
165 struct net_device
*dev
= alloc_etherdev(sizeof(struct net_local
));
169 return ERR_PTR(-ENOMEM
);
171 sprintf(dev
->name
, "eth%d", unit
);
172 netdev_boot_setup_check(dev
);
174 err
= do_netcard_probe(dev
);
185 * This is the real probe routine. Linux has a history of friendly device
186 * probes on the ISA bus. A good device probes avoids doing writes, and
187 * verifies that the correct device exists and functions.
189 static int __init
netcard_probe1(struct net_device
*dev
, int ioaddr
)
191 struct net_local
*np
;
192 static unsigned version_printed
;
196 /* Grab the region so that no one else tries to probe our ioports. */
197 if (!request_region(ioaddr
, NETCARD_IO_EXTENT
, cardname
))
201 * For ethernet adaptors the first three octets of the station address
202 * contains the manufacturer's unique code. That might be a good probe
203 * method. Ideally you would add additional checks.
205 if (inb(ioaddr
+ 0) != SA_ADDR0
206 || inb(ioaddr
+ 1) != SA_ADDR1
207 || inb(ioaddr
+ 2) != SA_ADDR2
)
210 if (net_debug
&& version_printed
++ == 0)
211 printk(KERN_DEBUG
"%s", version
);
213 printk(KERN_INFO
"%s: %s found at %#3x, ", dev
->name
, cardname
, ioaddr
);
215 /* Fill in the 'dev' fields. */
216 dev
->base_addr
= ioaddr
;
218 /* Retrieve and print the ethernet address. */
219 for (i
= 0; i
< 6; i
++)
220 dev
->dev_addr
[i
] = inb(ioaddr
+ i
);
222 printk("%pM", dev
->dev_addr
);
225 #ifdef jumpered_interrupts
227 * If this board has jumpered interrupts, allocate the interrupt
228 * vector now. There is no point in waiting since no other device
229 * can use the interrupt, and this marks the irq as busy. Jumpered
230 * interrupts are typically not reported by the boards, and we must
231 * used autoIRQ to find them.
235 ; /* Do nothing: a user-level program will set it. */
236 else if (dev
->irq
< 2) { /* "Auto-IRQ" */
237 unsigned long irq_mask
= probe_irq_on();
238 /* Trigger an interrupt here. */
240 dev
->irq
= probe_irq_off(irq_mask
);
242 printk(" autoirq is %d", dev
->irq
);
243 } else if (dev
->irq
== 2)
245 * Fixup for users that don't know that IRQ 2 is really
246 * IRQ9, or don't know which one to set.
251 int irqval
= request_irq(dev
->irq
, &net_interrupt
, 0, cardname
, dev
);
253 printk("%s: unable to get IRQ %d (irqval=%d).\n",
254 dev
->name
, dev
->irq
, irqval
);
258 #endif /* jumpered interrupt */
261 * If we use a jumpered DMA channel, that should be probed for and
262 * allocated here as well. See lance.c for an example.
265 if (request_dma(dev
->dma
, cardname
)) {
266 printk("DMA %d allocation failed.\n", dev
->dma
);
269 printk(", assigned DMA %d.\n", dev
->dma
);
271 short dma_status
, new_dma_status
;
273 /* Read the DMA channel status registers. */
274 dma_status
= ((inb(DMA1_STAT_REG
) >> 4) & 0x0f) |
275 (inb(DMA2_STAT_REG
) & 0xf0);
276 /* Trigger a DMA request, perhaps pause a bit. */
277 outw(0x1234, ioaddr
+ 8);
278 /* Re-read the DMA status registers. */
279 new_dma_status
= ((inb(DMA1_STAT_REG
) >> 4) & 0x0f) |
280 (inb(DMA2_STAT_REG
) & 0xf0);
282 * Eliminate the old and floating requests,
283 * and DMA4 the cascade.
285 new_dma_status
^= dma_status
;
286 new_dma_status
&= ~0x10;
287 for (i
= 7; i
> 0; i
--)
288 if (test_bit(i
, &new_dma_status
)) {
293 printk("DMA probe failed.\n");
296 if (request_dma(dev
->dma
, cardname
)) {
297 printk("probed DMA %d allocation failed.\n", dev
->dma
);
301 #endif /* jumpered DMA */
303 np
= netdev_priv(dev
);
304 spin_lock_init(&np
->lock
);
306 dev
->open
= net_open
;
307 dev
->stop
= net_close
;
308 dev
->hard_start_xmit
= net_send_packet
;
309 dev
->get_stats
= net_get_stats
;
310 dev
->set_multicast_list
= &set_multicast_list
;
312 dev
->tx_timeout
= &net_tx_timeout
;
313 dev
->watchdog_timeo
= MY_TX_TIMEOUT
;
315 err
= register_netdev(dev
);
324 #ifdef jumpered_interrupts
325 free_irq(dev
->irq
, dev
);
328 release_region(base_addr
, NETCARD_IO_EXTENT
);
332 static void net_tx_timeout(struct net_device
*dev
)
334 struct net_local
*np
= netdev_priv(dev
);
336 printk(KERN_WARNING
"%s: transmit timed out, %s?\n", dev
->name
,
337 tx_done(dev
) ? "IRQ conflict" : "network cable problem");
339 /* Try to restart the adaptor. */
340 chipset_init(dev
, 1);
342 np
->stats
.tx_errors
++;
344 /* If we have space available to accept new transmit
345 * requests, wake up the queueing layer. This would
346 * be the case if the chipset_init() call above just
347 * flushes out the tx queue and empties it.
349 * If instead, the tx queue is retained then the
350 * netif_wake_queue() call should be placed in the
351 * TX completion interrupt handler of the driver instead
355 netif_wake_queue(dev
);
359 * Open/initialize the board. This is called (in the current kernel)
360 * sometime after booting when the 'ifconfig' program is run.
362 * This routine should set everything up anew at each open, even
363 * registers that "should" only need to be set once at boot, so that
364 * there is non-reboot way to recover if something goes wrong.
367 net_open(struct net_device
*dev
)
369 struct net_local
*np
= netdev_priv(dev
);
370 int ioaddr
= dev
->base_addr
;
372 * This is used if the interrupt line can turned off (shared).
373 * See 3c503.c for an example of selecting the IRQ at config-time.
375 if (request_irq(dev
->irq
, &net_interrupt
, 0, cardname
, dev
)) {
379 * Always allocate the DMA channel after the IRQ,
380 * and clean up on failure.
382 if (request_dma(dev
->dma
, cardname
)) {
383 free_irq(dev
->irq
, dev
);
387 /* Reset the hardware here. Don't forget to set the station address. */
388 chipset_init(dev
, 1);
390 np
->open_time
= jiffies
;
392 /* We are now ready to accept transmit requeusts from
393 * the queueing layer of the networking.
395 netif_start_queue(dev
);
400 /* This will only be invoked if your driver is _not_ in XOFF state.
401 * What this means is that you need not check it, and that this
402 * invariant will hold if you make sure that the netif_*_queue()
403 * calls are done at the proper times.
405 static int net_send_packet(struct sk_buff
*skb
, struct net_device
*dev
)
407 struct net_local
*np
= netdev_priv(dev
);
408 int ioaddr
= dev
->base_addr
;
409 short length
= ETH_ZLEN
< skb
->len
? skb
->len
: ETH_ZLEN
;
410 unsigned char *buf
= skb
->data
;
412 /* If some error occurs while trying to transmit this
413 * packet, you should return '1' from this function.
414 * In such a case you _may not_ do anything to the
415 * SKB, it is still owned by the network queueing
416 * layer when an error is returned. This means you
417 * may not modify any SKB fields, you may not free
422 /* This is the most common case for modern hardware.
423 * The spinlock protects this code from the TX complete
424 * hardware interrupt handler. Queue flow control is
425 * thus managed under this lock as well.
427 spin_lock_irq(&np
->lock
);
429 add_to_tx_ring(np
, skb
, length
);
430 dev
->trans_start
= jiffies
;
432 /* If we just used up the very last entry in the
433 * TX ring on this device, tell the queueing
434 * layer to send no more.
437 netif_stop_queue(dev
);
439 /* When the TX completion hw interrupt arrives, this
440 * is when the transmit statistics are updated.
443 spin_unlock_irq(&np
->lock
);
445 /* This is the case for older hardware which takes
446 * a single transmit buffer at a time, and it is
447 * just written to the device via PIO.
449 * No spin locking is needed since there is no TX complete
450 * event. If by chance your card does have a TX complete
451 * hardware IRQ then you may need to utilize np->lock here.
453 hardware_send_packet(ioaddr
, buf
, length
);
454 np
->stats
.tx_bytes
+= skb
->len
;
456 dev
->trans_start
= jiffies
;
458 /* You might need to clean up and record Tx statistics here. */
459 if (inw(ioaddr
) == /*RU*/81)
460 np
->stats
.tx_aborted_errors
++;
468 /* This handles TX complete events posted by the device
471 void net_tx(struct net_device
*dev
)
473 struct net_local
*np
= netdev_priv(dev
);
476 /* This protects us from concurrent execution of
477 * our dev->hard_start_xmit function above.
479 spin_lock(&np
->lock
);
482 while (tx_entry_is_sent(np
, entry
)) {
483 struct sk_buff
*skb
= np
->skbs
[entry
];
485 np
->stats
.tx_bytes
+= skb
->len
;
486 dev_kfree_skb_irq (skb
);
488 entry
= next_tx_entry(np
, entry
);
492 /* If we had stopped the queue due to a "tx full"
493 * condition, and space has now been made available,
496 if (netif_queue_stopped(dev
) && ! tx_full(dev
))
497 netif_wake_queue(dev
);
499 spin_unlock(&np
->lock
);
504 * The typical workload of the driver:
505 * Handle the network interface interrupts.
507 static irqreturn_t
net_interrupt(int irq
, void *dev_id
)
509 struct net_device
*dev
= dev_id
;
510 struct net_local
*np
;
514 ioaddr
= dev
->base_addr
;
516 np
= netdev_priv(dev
);
517 status
= inw(ioaddr
+ 0);
523 if (status
& RX_INTR
) {
524 /* Got a packet(s). */
528 if (status
& TX_INTR
) {
529 /* Transmit complete. */
531 np
->stats
.tx_packets
++;
532 netif_wake_queue(dev
);
535 if (status
& COUNTERS_INTR
) {
536 /* Increment the appropriate 'localstats' field. */
537 np
->stats
.tx_window_errors
++;
540 return IRQ_RETVAL(handled
);
543 /* We have a good packet(s), get it/them out of the buffers. */
545 net_rx(struct net_device
*dev
)
547 struct net_local
*lp
= netdev_priv(dev
);
548 int ioaddr
= dev
->base_addr
;
552 int status
= inw(ioaddr
);
553 int pkt_len
= inw(ioaddr
);
555 if (pkt_len
== 0) /* Read all the frames? */
556 break; /* Done for now */
558 if (status
& 0x40) { /* There was an error. */
559 lp
->stats
.rx_errors
++;
560 if (status
& 0x20) lp
->stats
.rx_frame_errors
++;
561 if (status
& 0x10) lp
->stats
.rx_over_errors
++;
562 if (status
& 0x08) lp
->stats
.rx_crc_errors
++;
563 if (status
& 0x04) lp
->stats
.rx_fifo_errors
++;
565 /* Malloc up new buffer. */
568 lp
->stats
.rx_bytes
+=pkt_len
;
570 skb
= dev_alloc_skb(pkt_len
);
572 printk(KERN_NOTICE
"%s: Memory squeeze, dropping packet.\n",
574 lp
->stats
.rx_dropped
++;
579 /* 'skb->data' points to the start of sk_buff data area. */
580 memcpy(skb_put(skb
,pkt_len
), (void*)dev
->rmem_start
,
583 insw(ioaddr
, skb
->data
, (pkt_len
+ 1) >> 1);
586 lp
->stats
.rx_packets
++;
587 lp
->stats
.rx_bytes
+= pkt_len
;
589 } while (--boguscount
);
594 /* The inverse routine to net_open(). */
596 net_close(struct net_device
*dev
)
598 struct net_local
*lp
= netdev_priv(dev
);
599 int ioaddr
= dev
->base_addr
;
603 netif_stop_queue(dev
);
605 /* Flush the Tx and disable Rx here. */
607 disable_dma(dev
->dma
);
609 /* If not IRQ or DMA jumpered, free up the line. */
610 outw(0x00, ioaddr
+0); /* Release the physical interrupt line. */
612 free_irq(dev
->irq
, dev
);
615 /* Update the statistics here. */
622 * Get the current statistics.
623 * This may be called with the card open or closed.
625 static struct net_device_stats
*net_get_stats(struct net_device
*dev
)
627 struct net_local
*lp
= netdev_priv(dev
);
628 short ioaddr
= dev
->base_addr
;
630 /* Update the statistics from the device registers. */
631 lp
->stats
.rx_missed_errors
= inw(ioaddr
+1);
636 * Set or clear the multicast filter for this adaptor.
637 * num_addrs == -1 Promiscuous mode, receive all packets
638 * num_addrs == 0 Normal mode, clear multicast list
639 * num_addrs > 0 Multicast mode, receive normal and MC packets,
640 * and do best-effort filtering.
643 set_multicast_list(struct net_device
*dev
)
645 short ioaddr
= dev
->base_addr
;
646 if (dev
->flags
&IFF_PROMISC
)
648 /* Enable promiscuous mode */
649 outw(MULTICAST
|PROMISC
, ioaddr
);
651 else if((dev
->flags
&IFF_ALLMULTI
) || dev
->mc_count
> HW_MAX_ADDRS
)
653 /* Disable promiscuous mode, use normal mode. */
654 hardware_set_filter(NULL
);
656 outw(MULTICAST
, ioaddr
);
658 else if(dev
->mc_count
)
660 /* Walk the address list, and load the filter */
661 hardware_set_filter(dev
->mc_list
);
663 outw(MULTICAST
, ioaddr
);
671 static struct net_device
*this_device
;
672 static int io
= 0x300;
676 MODULE_LICENSE("GPL");
678 int init_module(void)
680 struct net_device
*dev
;
684 printk(KERN_WARNING
"%s: You shouldn't use auto-probing with insmod!\n",
686 dev
= alloc_etherdev(sizeof(struct net_local
));
690 /* Copy the parameters from insmod into the device structure. */
694 dev
->mem_start
= mem
;
695 if (do_netcard_probe(dev
) == 0) {
706 unregister_netdev(this_device
);
707 cleanup_card(this_device
);
708 free_netdev(this_device
);
716 * gcc -D__KERNEL__ -Wall -Wstrict-prototypes -Wwrite-strings
717 * -Wredundant-decls -O2 -m486 -c skeleton.c
719 * kept-new-versions: 5
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