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
, struct pt_regs
*regs
);
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 SET_MODULE_OWNER(dev
);
138 if (base_addr
> 0x1ff) /* Check a single specified location. */
139 return netcard_probe1(dev
, base_addr
);
140 else if (base_addr
!= 0) /* Don't probe at all. */
143 for (i
= 0; netcard_portlist
[i
]; i
++) {
144 int ioaddr
= netcard_portlist
[i
];
145 if (netcard_probe1(dev
, ioaddr
) == 0)
153 static void cleanup_card(struct net_device
*dev
)
158 #ifdef jumpered_interrupts
159 free_irq(dev
->irq
, dev
);
161 release_region(dev
->base_addr
, NETCARD_IO_EXTENT
);
165 struct net_device
* __init
netcard_probe(int unit
)
167 struct net_device
*dev
= alloc_etherdev(sizeof(struct net_local
));
171 return ERR_PTR(-ENOMEM
);
173 sprintf(dev
->name
, "eth%d", unit
);
174 netdev_boot_setup_check(dev
);
176 err
= do_netcard_probe(dev
);
179 err
= register_netdev(dev
);
192 * This is the real probe routine. Linux has a history of friendly device
193 * probes on the ISA bus. A good device probes avoids doing writes, and
194 * verifies that the correct device exists and functions.
196 static int __init
netcard_probe1(struct net_device
*dev
, int ioaddr
)
198 struct net_local
*np
;
199 static unsigned version_printed
;
203 /* Grab the region so that no one else tries to probe our ioports. */
204 if (!request_region(ioaddr
, NETCARD_IO_EXTENT
, cardname
))
208 * For ethernet adaptors the first three octets of the station address
209 * contains the manufacturer's unique code. That might be a good probe
210 * method. Ideally you would add additional checks.
212 if (inb(ioaddr
+ 0) != SA_ADDR0
213 || inb(ioaddr
+ 1) != SA_ADDR1
214 || inb(ioaddr
+ 2) != SA_ADDR2
)
217 if (net_debug
&& version_printed
++ == 0)
218 printk(KERN_DEBUG
"%s", version
);
220 printk(KERN_INFO
"%s: %s found at %#3x, ", dev
->name
, cardname
, ioaddr
);
222 /* Fill in the 'dev' fields. */
223 dev
->base_addr
= ioaddr
;
225 /* Retrieve and print the ethernet address. */
226 for (i
= 0; i
< 6; i
++)
227 printk(" %2.2x", dev
->dev_addr
[i
] = inb(ioaddr
+ i
));
230 #ifdef jumpered_interrupts
232 * If this board has jumpered interrupts, allocate the interrupt
233 * vector now. There is no point in waiting since no other device
234 * can use the interrupt, and this marks the irq as busy. Jumpered
235 * interrupts are typically not reported by the boards, and we must
236 * used autoIRQ to find them.
240 ; /* Do nothing: a user-level program will set it. */
241 else if (dev
->irq
< 2) { /* "Auto-IRQ" */
242 unsigned long irq_mask
= probe_irq_on();
243 /* Trigger an interrupt here. */
245 dev
->irq
= probe_irq_off(irq_mask
);
247 printk(" autoirq is %d", dev
->irq
);
248 } else if (dev
->irq
== 2)
250 * Fixup for users that don't know that IRQ 2 is really
251 * IRQ9, or don't know which one to set.
256 int irqval
= request_irq(dev
->irq
, &net_interrupt
, 0, cardname
, dev
);
258 printk("%s: unable to get IRQ %d (irqval=%d).\n",
259 dev
->name
, dev
->irq
, irqval
);
263 #endif /* jumpered interrupt */
266 * If we use a jumpered DMA channel, that should be probed for and
267 * allocated here as well. See lance.c for an example.
270 if (request_dma(dev
->dma
, cardname
)) {
271 printk("DMA %d allocation failed.\n", dev
->dma
);
274 printk(", assigned DMA %d.\n", dev
->dma
);
276 short dma_status
, new_dma_status
;
278 /* Read the DMA channel status registers. */
279 dma_status
= ((inb(DMA1_STAT_REG
) >> 4) & 0x0f) |
280 (inb(DMA2_STAT_REG
) & 0xf0);
281 /* Trigger a DMA request, perhaps pause a bit. */
282 outw(0x1234, ioaddr
+ 8);
283 /* Re-read the DMA status registers. */
284 new_dma_status
= ((inb(DMA1_STAT_REG
) >> 4) & 0x0f) |
285 (inb(DMA2_STAT_REG
) & 0xf0);
287 * Eliminate the old and floating requests,
288 * and DMA4 the cascade.
290 new_dma_status
^= dma_status
;
291 new_dma_status
&= ~0x10;
292 for (i
= 7; i
> 0; i
--)
293 if (test_bit(i
, &new_dma_status
)) {
298 printk("DMA probe failed.\n");
301 if (request_dma(dev
->dma
, cardname
)) {
302 printk("probed DMA %d allocation failed.\n", dev
->dma
);
306 #endif /* jumpered DMA */
308 np
= netdev_priv(dev
);
309 spin_lock_init(&np
->lock
);
311 dev
->open
= net_open
;
312 dev
->stop
= net_close
;
313 dev
->hard_start_xmit
= net_send_packet
;
314 dev
->get_stats
= net_get_stats
;
315 dev
->set_multicast_list
= &set_multicast_list
;
317 dev
->tx_timeout
= &net_tx_timeout
;
318 dev
->watchdog_timeo
= MY_TX_TIMEOUT
;
321 #ifdef jumpered_interrupts
322 free_irq(dev
->irq
, dev
);
325 release_region(base_addr
, NETCARD_IO_EXTENT
);
329 static void net_tx_timeout(struct net_device
*dev
)
331 struct net_local
*np
= netdev_priv(dev
);
333 printk(KERN_WARNING
"%s: transmit timed out, %s?\n", dev
->name
,
334 tx_done(dev
) ? "IRQ conflict" : "network cable problem");
336 /* Try to restart the adaptor. */
337 chipset_init(dev
, 1);
339 np
->stats
.tx_errors
++;
341 /* If we have space available to accept new transmit
342 * requests, wake up the queueing layer. This would
343 * be the case if the chipset_init() call above just
344 * flushes out the tx queue and empties it.
346 * If instead, the tx queue is retained then the
347 * netif_wake_queue() call should be placed in the
348 * TX completion interrupt handler of the driver instead
352 netif_wake_queue(dev
);
356 * Open/initialize the board. This is called (in the current kernel)
357 * sometime after booting when the 'ifconfig' program is run.
359 * This routine should set everything up anew at each open, even
360 * registers that "should" only need to be set once at boot, so that
361 * there is non-reboot way to recover if something goes wrong.
364 net_open(struct net_device
*dev
)
366 struct net_local
*np
= netdev_priv(dev
);
367 int ioaddr
= dev
->base_addr
;
369 * This is used if the interrupt line can turned off (shared).
370 * See 3c503.c for an example of selecting the IRQ at config-time.
372 if (request_irq(dev
->irq
, &net_interrupt
, 0, cardname
, dev
)) {
376 * Always allocate the DMA channel after the IRQ,
377 * and clean up on failure.
379 if (request_dma(dev
->dma
, cardname
)) {
380 free_irq(dev
->irq
, dev
);
384 /* Reset the hardware here. Don't forget to set the station address. */
385 chipset_init(dev
, 1);
387 np
->open_time
= jiffies
;
389 /* We are now ready to accept transmit requeusts from
390 * the queueing layer of the networking.
392 netif_start_queue(dev
);
397 /* This will only be invoked if your driver is _not_ in XOFF state.
398 * What this means is that you need not check it, and that this
399 * invariant will hold if you make sure that the netif_*_queue()
400 * calls are done at the proper times.
402 static int net_send_packet(struct sk_buff
*skb
, struct net_device
*dev
)
404 struct net_local
*np
= netdev_priv(dev
);
405 int ioaddr
= dev
->base_addr
;
406 short length
= ETH_ZLEN
< skb
->len
? skb
->len
: ETH_ZLEN
;
407 unsigned char *buf
= skb
->data
;
409 /* If some error occurs while trying to transmit this
410 * packet, you should return '1' from this function.
411 * In such a case you _may not_ do anything to the
412 * SKB, it is still owned by the network queueing
413 * layer when an error is returned. This means you
414 * may not modify any SKB fields, you may not free
419 /* This is the most common case for modern hardware.
420 * The spinlock protects this code from the TX complete
421 * hardware interrupt handler. Queue flow control is
422 * thus managed under this lock as well.
424 spin_lock_irq(&np
->lock
);
426 add_to_tx_ring(np
, skb
, length
);
427 dev
->trans_start
= jiffies
;
429 /* If we just used up the very last entry in the
430 * TX ring on this device, tell the queueing
431 * layer to send no more.
434 netif_stop_queue(dev
);
436 /* When the TX completion hw interrupt arrives, this
437 * is when the transmit statistics are updated.
440 spin_unlock_irq(&np
->lock
);
442 /* This is the case for older hardware which takes
443 * a single transmit buffer at a time, and it is
444 * just written to the device via PIO.
446 * No spin locking is needed since there is no TX complete
447 * event. If by chance your card does have a TX complete
448 * hardware IRQ then you may need to utilize np->lock here.
450 hardware_send_packet(ioaddr
, buf
, length
);
451 np
->stats
.tx_bytes
+= skb
->len
;
453 dev
->trans_start
= jiffies
;
455 /* You might need to clean up and record Tx statistics here. */
456 if (inw(ioaddr
) == /*RU*/81)
457 np
->stats
.tx_aborted_errors
++;
465 /* This handles TX complete events posted by the device
468 void net_tx(struct net_device
*dev
)
470 struct net_local
*np
= netdev_priv(dev
);
473 /* This protects us from concurrent execution of
474 * our dev->hard_start_xmit function above.
476 spin_lock(&np
->lock
);
479 while (tx_entry_is_sent(np
, entry
)) {
480 struct sk_buff
*skb
= np
->skbs
[entry
];
482 np
->stats
.tx_bytes
+= skb
->len
;
483 dev_kfree_skb_irq (skb
);
485 entry
= next_tx_entry(np
, entry
);
489 /* If we had stopped the queue due to a "tx full"
490 * condition, and space has now been made available,
493 if (netif_queue_stopped(dev
) && ! tx_full(dev
))
494 netif_wake_queue(dev
);
496 spin_unlock(&np
->lock
);
501 * The typical workload of the driver:
502 * Handle the network interface interrupts.
504 static irqreturn_t
net_interrupt(int irq
, void *dev_id
, struct pt_regs
* regs
)
506 struct net_device
*dev
= dev_id
;
507 struct net_local
*np
;
511 ioaddr
= dev
->base_addr
;
513 np
= netdev_priv(dev
);
514 status
= inw(ioaddr
+ 0);
520 if (status
& RX_INTR
) {
521 /* Got a packet(s). */
525 if (status
& TX_INTR
) {
526 /* Transmit complete. */
528 np
->stats
.tx_packets
++;
529 netif_wake_queue(dev
);
532 if (status
& COUNTERS_INTR
) {
533 /* Increment the appropriate 'localstats' field. */
534 np
->stats
.tx_window_errors
++;
537 return IRQ_RETVAL(handled
);
540 /* We have a good packet(s), get it/them out of the buffers. */
542 net_rx(struct net_device
*dev
)
544 struct net_local
*lp
= netdev_priv(dev
);
545 int ioaddr
= dev
->base_addr
;
549 int status
= inw(ioaddr
);
550 int pkt_len
= inw(ioaddr
);
552 if (pkt_len
== 0) /* Read all the frames? */
553 break; /* Done for now */
555 if (status
& 0x40) { /* There was an error. */
556 lp
->stats
.rx_errors
++;
557 if (status
& 0x20) lp
->stats
.rx_frame_errors
++;
558 if (status
& 0x10) lp
->stats
.rx_over_errors
++;
559 if (status
& 0x08) lp
->stats
.rx_crc_errors
++;
560 if (status
& 0x04) lp
->stats
.rx_fifo_errors
++;
562 /* Malloc up new buffer. */
565 lp
->stats
.rx_bytes
+=pkt_len
;
567 skb
= dev_alloc_skb(pkt_len
);
569 printk(KERN_NOTICE
"%s: Memory squeeze, dropping packet.\n",
571 lp
->stats
.rx_dropped
++;
576 /* 'skb->data' points to the start of sk_buff data area. */
577 memcpy(skb_put(skb
,pkt_len
), (void*)dev
->rmem_start
,
580 insw(ioaddr
, skb
->data
, (pkt_len
+ 1) >> 1);
583 dev
->last_rx
= jiffies
;
584 lp
->stats
.rx_packets
++;
585 lp
->stats
.rx_bytes
+= pkt_len
;
587 } while (--boguscount
);
592 /* The inverse routine to net_open(). */
594 net_close(struct net_device
*dev
)
596 struct net_local
*lp
= netdev_priv(dev
);
597 int ioaddr
= dev
->base_addr
;
601 netif_stop_queue(dev
);
603 /* Flush the Tx and disable Rx here. */
605 disable_dma(dev
->dma
);
607 /* If not IRQ or DMA jumpered, free up the line. */
608 outw(0x00, ioaddr
+0); /* Release the physical interrupt line. */
610 free_irq(dev
->irq
, dev
);
613 /* Update the statistics here. */
620 * Get the current statistics.
621 * This may be called with the card open or closed.
623 static struct net_device_stats
*net_get_stats(struct net_device
*dev
)
625 struct net_local
*lp
= netdev_priv(dev
);
626 short ioaddr
= dev
->base_addr
;
628 /* Update the statistics from the device registers. */
629 lp
->stats
.rx_missed_errors
= inw(ioaddr
+1);
634 * Set or clear the multicast filter for this adaptor.
635 * num_addrs == -1 Promiscuous mode, receive all packets
636 * num_addrs == 0 Normal mode, clear multicast list
637 * num_addrs > 0 Multicast mode, receive normal and MC packets,
638 * and do best-effort filtering.
641 set_multicast_list(struct net_device
*dev
)
643 short ioaddr
= dev
->base_addr
;
644 if (dev
->flags
&IFF_PROMISC
)
646 /* Enable promiscuous mode */
647 outw(MULTICAST
|PROMISC
, ioaddr
);
649 else if((dev
->flags
&IFF_ALLMULTI
) || dev
->mc_count
> HW_MAX_ADDRS
)
651 /* Disable promiscuous mode, use normal mode. */
652 hardware_set_filter(NULL
);
654 outw(MULTICAST
, ioaddr
);
656 else if(dev
->mc_count
)
658 /* Walk the address list, and load the filter */
659 hardware_set_filter(dev
->mc_list
);
661 outw(MULTICAST
, ioaddr
);
669 static struct net_device
*this_device
;
670 static int io
= 0x300;
674 MODULE_LICENSE("GPL");
676 int init_module(void)
678 struct net_device
*dev
;
682 printk(KERN_WARNING
"%s: You shouldn't use auto-probing with insmod!\n",
684 dev
= alloc_etherdev(sizeof(struct net_local
));
688 /* Copy the parameters from insmod into the device structure. */
692 dev
->mem_start
= mem
;
693 if (do_netcard_probe(dev
) == 0) {
694 if (register_netdev(dev
) == 0)
707 unregister_netdev(this_device
);
708 cleanup_card(this_device
);
709 free_netdev(this_device
);
717 * gcc -D__KERNEL__ -Wall -Wstrict-prototypes -Wwrite-strings
718 * -Wredundant-decls -O2 -m486 -c skeleton.c
720 * kept-new-versions: 5