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1 /* skeleton.c: A sample network driver core for linux. */
2 /*
3 Written 1993 by Donald Becker.
4 Copyright 1993 United States Government as represented by the Director,
5 National Security Agency. This software may only be used and distributed
6 according to the terms of the GNU Public License as modified by SRC,
7 incorporated herein by reference.
8
9 The author may be reached as becker@super.org or
10 C/O Supercomputing Research Ctr., 17100 Science Dr., Bowie MD 20715
11
12 This file is an outline for writing a network device driver for the
13 the Linux operating system.
14
15 To write (or understand) a driver, have a look at the "loopback.c" file to
16 get a feel of what is going on, and then use the code below as a skeleton
17 for the new driver.
18
19 */
20
21 static char *version =
22 "skeleton.c:v0.05 11/16/93 Donald Becker (becker@super.org)\n";
23
24 /* Always include 'config.h' first in case the user wants to turn on
25 or override something. */
26 #include <linux/config.h>
27
28 /*
29 Sources:
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
36 compatible.
37
38 Finally, keep in mind that the Linux kernel is has an API, not
39 ABI. Proprietary object-code-only distributions are not permitted
40 under the GPL.
41 */
42
43 #include <linux/kernel.h>
44 #include <linux/sched.h>
45 #include <linux/types.h>
46 #include <linux/fcntl.h>
47 #include <linux/interrupt.h>
48 #include <linux/ptrace.h>
49 #include <linux/ioport.h>
50 #include <linux/in.h>
51 #include <linux/malloc.h>
52 #include <linux/string.h>
53 #include <asm/system.h>
54 #include <asm/bitops.h>
55 #include <asm/io.h>
56 #include <asm/dma.h>
57 #include <errno.h>
58
59 #include "dev.h"
60 #include "eth.h"
61 #include "skbuff.h"
62 #include "arp.h"
63
64 #ifndef HAVE_AUTOIRQ
65 /* From auto_irq.c, in ioport.h for later versions. */
66 extern void autoirq_setup(int waittime);
67 extern int autoirq_report(int waittime);
68 /* The map from IRQ number (as passed to the interrupt handler) to
69 'struct device'. */
70 extern struct device *irq2dev_map[16];
71 #endif
72
73 #ifndef HAVE_ALLOC_SKB
74 #define alloc_skb(size, priority) (struct sk_buff *) kmalloc(size,priority)
75 #define kfree_skbmem(addr, size) kfree_s(addr,size);
76 #endif
77
78 #ifndef HAVE_PORTRESERVE
79 #define check_region(ioaddr, size) 0
80 #define snarf_region(ioaddr, size); do ; while (0)
81 #endif
82
83 /* use 0 for production, 1 for verification, >2 for debug */
84 #ifndef NET_DEBUG
85 #define NET_DEBUG 2
86 #endif
87 static unsigned int net_debug = NET_DEBUG;
88
89 /* Information that need to be kept for each board. */
90 struct net_local {
91 struct enet_statistics stats;
92 long open_time; /* Useless example local info. */
93 };
94
95 /* The number of low I/O ports used by the ethercard. */
96 #define ETHERCARD_TOTAL_SIZE 16
97
98 /* The station (ethernet) address prefix, used for IDing the board. */
99 #define SA_ADDR0 0x00
100 #define SA_ADDR1 0x42
101 #define SA_ADDR2 0x65
102
103 /* Index to functions, as function prototypes. */
104
105 extern int netcard_probe(struct device *dev);
106
107 static int netcard_probe1(struct device *dev, short ioaddr);
108 static int net_open(struct device *dev);
109 static int net_send_packet(struct sk_buff *skb, struct device *dev);
110 static void net_interrupt(int reg_ptr);
111 static void net_rx(struct device *dev);
112 static int net_close(struct device *dev);
113 static struct enet_statistics *net_get_stats(struct device *dev);
114 #ifdef HAVE_MULTICAST
115 static void set_multicast_list(struct device *dev, int num_addrs, void *addrs);
116 #endif
117
118 /* Example routines you must write ;->. */
119 #define tx_done(dev) 1
120 extern void hardware_send_packet(short ioaddr, char *buf, int length);
121 extern void chipset_init(struct device *dev, int startp);
122
123
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, alloate space for the device and return success
128 (detachable devices only).
129 */
130 int
131 netcard_probe(struct device *dev)
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*/
132 {
133 int *port, ports[] = {0x300, 0x280, 0};
134 int base_addr = dev->base_addr;
135
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. */
139 return ENXIO;
140
141 for (port = &ports[0]; *port; port++) {
142 int ioaddr = *port;
143 if (check_region(ioaddr, ETHERCARD_TOTAL_SIZE))
144 continue;
145 if (inb(ioaddr) != 0x57)
146 continue;
147 dev->base_addr = ioaddr;
148 if (netcard_probe1(dev, ioaddr) == 0)
149 return 0;
150 }
151
152 dev->base_addr = base_addr;
153 return ENODEV;
154 }
155
156 int netcard_probe1(struct device *dev, short ioaddr)
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*/
157 {
158 unsigned char station_addr[6];
159 int i;
160
161 /* Read the station address PROM. */
162 for (i = 0; i < 6; i++) {
163 station_addr[i] = inb(ioaddr + i);
164 }
165 /* Check the first three octets of the S.A. for the manufactor's code. */
166 if (station_addr[0] != SA_ADDR0
167 || station_addr[1] != SA_ADDR1 || station_addr[2] != SA_ADDR2) {
168 return ENODEV;
169 }
170
171 printk("%s: %s found at %#3x, IRQ %d.\n", dev->name,
172 "network card", dev->base_addr, dev->irq);
173
174 #ifdef jumpered_interrupts
175 /* If this board has jumpered interrupts, snarf the interrupt vector
176 now. There is no point in waiting since no other device can use
177 the interrupt, and this marks the 'irqaction' as busy. */
178
179 if (dev->irq == -1)
180 ; /* Do nothing: a user-level program will set it. */
181 else if (dev->irq < 2) { /* "Auto-IRQ" */
182 autoirq_setup(0);
183 /* Trigger an interrupt here. */
184
185 dev->irq = autoirq_report(0);
186 if (net_debug >= 2)
187 printk(" autoirq is %d", dev->irq);
188 } else if (dev->irq == 2)
189 /* Fixup for users that don't know that IRQ 2 is really IRQ 9,
190 or don't know which one to set. */
191 dev->irq = 9;
192
193 { int irqval = request_irq(dev->irq, &net_interrupt);
194 if (irqval) {
195 printk ("%s: unable to get IRQ %d (irqval=%d).\n", dev->name,
196 dev->irq, irqval);
197 return EAGAIN;
198 }
199 }
200 #endif /* jumpered interrupt */
201
202 /* Grab the region so we can find another board if autoIRQ fails. */
203 snarf_region(ioaddr, ETHERCARD_TOTAL_SIZE);
204
205 if (net_debug)
206 printk(version);
207
208 /* Initialize the device structure. */
209 dev->priv = kmalloc(sizeof(struct net_local), GFP_KERNEL);
210 memset(dev->priv, 0, sizeof(struct net_local));
211
212 dev->open = net_open;
213 dev->stop = net_close;
214 dev->hard_start_xmit = net_send_packet;
215 dev->get_stats = net_get_stats;
216 #ifdef HAVE_MULTICAST
217 dev->set_multicast_list = &set_multicast_list;
218 #endif
219
220 /* Fill in the fields of the device structure with ethernet-generic values.
221 This should be in a common file instead of per-driver. */
222 for (i = 0; i < DEV_NUMBUFFS; i++)
223 dev->buffs[i] = NULL;
224
225 dev->hard_header = eth_header;
226 dev->add_arp = eth_add_arp;
227 dev->queue_xmit = dev_queue_xmit;
228 dev->rebuild_header = eth_rebuild_header;
229 dev->type_trans = eth_type_trans;
230
231 dev->type = ARPHRD_ETHER;
232 dev->hard_header_len = ETH_HLEN;
233 dev->mtu = 1500; /* eth_mtu */
234 dev->addr_len = ETH_ALEN;
235 for (i = 0; i < ETH_ALEN; i++) {
236 dev->broadcast[i]=0xff;
237 }
238
239 /* New-style flags. */
240 dev->flags = IFF_BROADCAST;
241 dev->family = AF_INET;
242 dev->pa_addr = 0;
243 dev->pa_brdaddr = 0;
244 dev->pa_mask = 0;
245 dev->pa_alen = sizeof(unsigned long);
246
247 return 0;
248 }
249
250
251 /* Open/initialize the board. This is called (in the current kernel)
252 sometime after booting when the 'ifconfig' program is run.
253
254 This routine should set everything up anew at each open, even
255 registers that "should" only need to be set once at boot, so that
256 there is non-reboot way to recover if something goes wrong.
257 */
258 static int
259 net_open(struct device *dev)
/* */
260 {
261 struct net_local *lp = (struct net_local *)dev->priv;
262 int ioaddr = dev->base_addr;
263
264 /* This is used if the interrupt line can turned off (shared).
265 See 3c503.c for an example of selecting the IRQ at config-time. */
266 if (request_irq(dev->irq, &net_interrupt)) {
267 return -EAGAIN;
268 }
269
270
271 /* Always snarf a DMA channel after the IRQ. */
272 if (request_dma(dev->dma)) {
273 free_irq(dev->irq);
274 return -EAGAIN;
275 }
276 irq2dev_map[dev->irq] = dev;
277
278 /* Reset the hardware here. */
279 /*chipset_init(dev, 1);*/
280 outb(0x00, ioaddr);
281 lp->open_time = jiffies;
282
283 dev->tbusy = 0;
284 dev->interrupt = 0;
285 dev->start = 1;
286 return 0;
287 }
288
289 static int
290 net_send_packet(struct sk_buff *skb, struct device *dev)
/* */
291 {
292 struct net_local *lp = (struct net_local *)dev->priv;
293 int ioaddr = dev->base_addr;
294
295 if (dev->tbusy) {
296 /* If we get here, some higher level has decided we are broken.
297 There should really be a "kick me" function call instead. */
298 int tickssofar = jiffies - dev->trans_start;
299 if (tickssofar < 5)
300 return 1;
301 printk("%s: transmit timed out, %s?\n", dev->name,
302 tx_done(dev) ? "IRQ conflict" : "network cable problem");
303 /* Try to restart the adaptor. */
304 chipset_init(dev, 1);
305 dev->tbusy=0;
306 dev->trans_start = jiffies;
307 }
308
309 /* If some higher layer thinks we've missed an tx-done interrupt
310 we are passed NULL. Caution: dev_tint() handles the cli()/sti()
311 itself. */
312 if (skb == NULL) {
313 dev_tint(dev);
314 return 0;
315 }
316
317 /* For ethernet, fill in the header. This should really be done by a
318 higher level, rather than duplicated for each ethernet adaptor. */
319 if (!skb->arp && dev->rebuild_header(skb->data, dev)) {
320 skb->dev = dev;
321 arp_queue (skb);
322 return 0;
323 }
324 skb->arp=1;
325
326 /* Block a timer-based transmit from overlapping. This could better be
327 done with atomic_swap(1, dev->tbusy), but set_bit() works as well. */
328 if (set_bit(0, (void*)&dev->tbusy) != 0)
329 printk("%s: Transmitter access conflict.\n", dev->name);
330 else {
331 short length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
332 unsigned char *buf = skb->data;
333
334 hardware_send_packet(ioaddr, buf, length);
335 dev->trans_start = jiffies;
336 }
337 if (skb->free)
338 kfree_skb (skb, FREE_WRITE);
339
340 /* You might need to clean up and record Tx statistics here. */
341 if (inw(ioaddr) == /*RU*/81)
342 lp->stats.tx_aborted_errors++;
343
344 return 0;
345 }
346
347 /* The typical workload of the driver:
348 Handle the network interface interrupts. */
349 static void
350 net_interrupt(int reg_ptr)
/* */
351 {
352 int irq = -(((struct pt_regs *)reg_ptr)->orig_eax+2);
353 struct device *dev = (struct device *)(irq2dev_map[irq]);
354 struct net_local *lp;
355 int ioaddr, status, boguscount = 0;
356
357 if (dev == NULL) {
358 printk ("net_interrupt(): irq %d for unknown device.\n", irq);
359 return;
360 }
361 dev->interrupt = 1;
362
363 ioaddr = dev->base_addr;
364 lp = (struct net_local *)dev->priv;
365 status = inw(ioaddr + 0);
366
367 do {
368 if (status /*& RX_INTR*/) {
369 /* Got a packet(s). */
370 net_rx(dev);
371 }
372 if (status /*& TX_INTR*/) {
373 lp->stats.tx_packets++;
374 dev->tbusy = 0;
375 mark_bh(INET_BH); /* Inform upper layers. */
376 }
377 if (status /*& COUNTERS_INTR*/) {
378 /* Increment the appropriate 'localstats' field. */
379 lp->stats.tx_window_errors++;
380 }
381 } while (++boguscount < 20) ;
382
383 return;
384 }
385
386 /* We have a good packet(s), get it/them out of the buffers. */
387 static void
388 net_rx(struct device *dev)
/* */
389 {
390 struct net_local *lp = (struct net_local *)dev->priv;
391 int ioaddr = dev->base_addr;
392 int boguscount = 10;
393
394 do {
395 int status = inw(ioaddr);
396 int pkt_len = inw(ioaddr);
397
398 if (pkt_len == 0) /* Read all the frames? */
399 break; /* Done for now */
400
401 if (status & 0x40) { /* There was an error. */
402 lp->stats.rx_errors++;
403 if (status & 0x20) lp->stats.rx_frame_errors++;
404 if (status & 0x10) lp->stats.rx_over_errors++;
405 if (status & 0x08) lp->stats.rx_crc_errors++;
406 if (status & 0x04) lp->stats.rx_fifo_errors++;
407 } else {
408 /* Malloc up new buffer. */
409 int sksize = sizeof(struct sk_buff) + pkt_len;
410 struct sk_buff *skb;
411
412 skb = alloc_skb(sksize, GFP_ATOMIC);
413 if (skb == NULL) {
414 printk("%s: Memory squeeze, dropping packet.\n", dev->name);
415 lp->stats.rx_dropped++;
416 break;
417 }
418 skb->mem_len = sksize;
419 skb->mem_addr = skb;
420 skb->len = pkt_len;
421 skb->dev = dev;
422
423 /* 'skb->data' points to the start of sk_buff data area. */
424 memcpy(skb->data, (void*)dev->rmem_start,
425 pkt_len);
426 /* or */
427 insw(ioaddr, skb->data, (pkt_len + 1) >> 1);
428
429 #ifdef HAVE_NETIF_RX
430 netif_rx(skb);
431 #else
432 skb->lock = 0;
433 if (dev_rint((unsigned char*)skb, pkt_len, IN_SKBUFF, dev) != 0) {
434 kfree_s(skb, sksize);
435 lp->stats.rx_dropped++;
436 break;
437 }
438 #endif
439 lp->stats.rx_packets++;
440 }
441 } while (--boguscount);
442
443 /* If any worth-while packets have been received, dev_rint()
444 has done a mark_bh(INET_BH) for us and will work on them
445 when we get to the bottom-half routine. */
446 return;
447 }
448
449 /* The inverse routine to net_open(). */
450 static int
451 net_close(struct device *dev)
/* */
452 {
453 struct net_local *lp = (struct net_local *)dev->priv;
454 int ioaddr = dev->base_addr;
455
456 lp->open_time = 0;
457
458 dev->tbusy = 1;
459 dev->start = 0;
460
461 /* Flush the Tx and disable Rx here. */
462
463 disable_dma(dev->dma);
464
465 /* If not IRQ or DMA jumpered, free up the line. */
466 outw(0x00, ioaddr+0); /* Release the physical interrupt line. */
467
468 free_irq(dev->irq);
469 free_dma(dev->dma);
470
471 irq2dev_map[dev->irq] = 0;
472
473 /* Update the statistics here. */
474
475 return 0;
476
477 }
478
479 /* Get the current statistics. This may be called with the card open or
480 closed. */
481 static struct enet_statistics *
482 net_get_stats(struct device *dev)
/* */
483 {
484 struct net_local *lp = (struct net_local *)dev->priv;
485 short ioaddr = dev->base_addr;
486
487 cli();
488 /* Update the statistics from the device registers. */
489 lp->stats.rx_missed_errors = inw(ioaddr+1);
490 sti();
491
492 return &lp->stats;
493 }
494
495 #ifdef HAVE_MULTICAST
496 /* Set or clear the multicast filter for this adaptor.
497 num_addrs == -1 Promiscuous mode, receive all packets
498 num_addrs == 0 Normal mode, clear multicast list
499 num_addrs > 0 Multicast mode, receive normal and MC packets, and do
500 best-effort filtering.
501 */
502 static void
503 set_multicast_list(struct device *dev, int num_addrs, void *addrs)
/* ![[last]](../icons/n_last.png)
*/
504 {
505 short ioaddr = dev->base_addr;
506 if (num_addrs) {
507 outw(69, ioaddr); /* Enable promiscuous mode */
508 } else
509 outw(99, ioaddr); /* Disable promiscuous mode, use normal mode */
510 }
511 #endif
512
513 /*
514 * Local variables:
515 * compile-command: "gcc -D__KERNEL__ -I/usr/src/linux/net/inet -Wall -Wstrict-prototypes -O6 -m486 -c skeleton.c"
516 * version-control: t
517 * kept-new-versions: 5
518 * tab-width: 4
519 * End:
520 */
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*/