Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
/* 3c501.c: A 3Com 3c501 Ethernet driver for Linux. */
/*
    Written 1992,1993,1994  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.

    This is a device driver for the 3Com Etherlink 3c501.
    Do not purchase this card, even as a joke.  It's performance is horrible,
    and it breaks in many ways.

    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

    Fixed (again!) the missing interrupt locking on TX/RX shifting.
    		Alan Cox <Alan.Cox@linux.org>

    Removed calls to init_etherdev since they are no longer needed, and
    cleaned up modularization just a bit. The driver still allows only
    the default address for cards when loaded as a module, but that's
    really less braindead than anyone using a 3c501 board. :)
		    19950208 (invid@msen.com)

    Added traps for interrupts hitting the window as we clear and TX load
    the board. Now getting 150K/second FTP with a 3c501 card. Still playing
    with a TX-TX optimisation to see if we can touch 180-200K/second as seems
    theoretically maximum.
    		19950402 Alan Cox <Alan.Cox@linux.org>

    Some notes on this thing if you have to hack it.  [Alan]

    1]	Some documentation is available from 3Com. Due to the boards age
    	standard responses when you ask for this will range from 'be serious'
    	to 'give it to a museum'. The documentation is incomplete and mostly
    	of historical interest anyway.

    2]  The basic system is a single buffer which can be used to receive or
    	transmit a packet. A third command mode exists when you are setting
    	things up.

    3]	If it's transmitting it's not receiving and vice versa. In fact the
    	time to get the board back into useful state after an operation is
    	quite large.

    4]	The driver works by keeping the board in receive mode waiting for a
    	packet to arrive. When one arrives it is copied out of the buffer
    	and delivered to the kernel. The card is reloaded and off we go.

    5]	When transmitting dev->tbusy is set and the card is reset (from
    	receive mode) [possibly losing a packet just received] to command
    	mode. A packet is loaded and transmit mode triggered. The interrupt
    	handler runs different code for transmit interrupts and can handle
    	returning to receive mode or retransmissions (yes you have to help
    	out with those too).

    Problems:
    	There are a wide variety of undocumented error returns from the card
    and you basically have to kick the board and pray if they turn up. Most
    only occur under extreme load or if you do something the board doesn't
    like (eg touching a register at the wrong time).

    	The driver is less efficient than it could be. It switches through
    receive mode even if more transmits are queued. If this worries you buy
    a real Ethernet card.

    	The combination of slow receive restart and no real multicast
    filter makes the board unusable with a kernel compiled for IP
    multicasting in a real multicast environment. That's down to the board,
    but even with no multicast programs running a multicast IP kernel is
    in group 224.0.0.1 and you will therefore be listening to all multicasts.
    One nv conference running over that Ethernet and you can give up.

*/

static const char *version =
    "3c501.c: 9/23/94 Donald Becker (becker@cesdis.gsfc.nasa.gov).\n";

/*
 *	Braindamage remaining:
 *	The 3c501 board.
 */

#include <linux/module.h>

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/ptrace.h>
#include <linux/fcntl.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/malloc.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/config.h>	/* for CONFIG_IP_MULTICAST */

#include <asm/bitops.h>
#include <asm/io.h>

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/init.h>

#define BLOCKOUT_2

/* A zero-terminated list of I/O addresses to be probed.
   The 3c501 can be at many locations, but here are the popular ones. */
static unsigned int netcard_portlist[] __initdata =
   { 0x280, 0x300, 0};


/*
 *	Index to functions.
 */

int el1_probe(struct device *dev);
static int  el1_probe1(struct device *dev, int ioaddr);
static int  el_open(struct device *dev);
static int  el_start_xmit(struct sk_buff *skb, struct device *dev);
static void el_interrupt(int irq, void *dev_id, struct pt_regs *regs);
static void el_receive(struct device *dev);
static void el_reset(struct device *dev);
static int  el1_close(struct device *dev);
static struct net_device_stats *el1_get_stats(struct device *dev);
static void set_multicast_list(struct device *dev);

#define EL1_IO_EXTENT	16

#ifndef EL_DEBUG
#define EL_DEBUG  0	/* use 0 for production, 1 for devel., >2 for debug */
#endif			/* Anything above 5 is wordy death! */
static int el_debug = EL_DEBUG;

/*
 *	Board-specific info in dev->priv.
 */

struct net_local
{
    struct net_device_stats stats;
    int tx_pkt_start;		/* The length of the current Tx packet. */
    int collisions;		/* Tx collisions this packet */
    int loading;		/* Spot buffer load collisions */
};


#define RX_STATUS (ioaddr + 0x06)
#define RX_CMD	  RX_STATUS
#define TX_STATUS (ioaddr + 0x07)
#define TX_CMD	  TX_STATUS
#define GP_LOW 	  (ioaddr + 0x08)
#define GP_HIGH   (ioaddr + 0x09)
#define RX_BUF_CLR (ioaddr + 0x0A)
#define RX_LOW	  (ioaddr + 0x0A)
#define RX_HIGH   (ioaddr + 0x0B)
#define SAPROM	  (ioaddr + 0x0C)
#define AX_STATUS (ioaddr + 0x0E)
#define AX_CMD	  AX_STATUS
#define DATAPORT  (ioaddr + 0x0F)
#define TX_RDY 0x08		/* In TX_STATUS */

#define EL1_DATAPTR	0x08
#define EL1_RXPTR	0x0A
#define EL1_SAPROM	0x0C
#define EL1_DATAPORT 	0x0f

/*
 *	Writes to the ax command register.
 */

#define AX_OFF	0x00			/* Irq off, buffer access on */
#define AX_SYS  0x40			/* Load the buffer */
#define AX_XMIT 0x44			/* Transmit a packet */
#define AX_RX	0x48			/* Receive a packet */
#define AX_LOOP	0x0C			/* Loopback mode */
#define AX_RESET 0x80

/*
 *	Normal receive mode written to RX_STATUS.  We must intr on short packets
 *	to avoid bogus rx lockups.
 */

#define RX_NORM 0xA8		/* 0x68 == all addrs, 0xA8 only to me. */
#define RX_PROM 0x68		/* Senior Prom, uhmm promiscuous mode. */
#define RX_MULT 0xE8		/* Accept multicast packets. */
#define TX_NORM 0x0A		/* Interrupt on everything that might hang the chip */

/*
 *	TX_STATUS register.
 */

#define TX_COLLISION 0x02
#define TX_16COLLISIONS 0x04
#define TX_READY 0x08

#define RX_RUNT 0x08
#define RX_MISSED 0x01		/* Missed a packet due to 3c501 braindamage. */
#define RX_GOOD	0x30		/* Good packet 0x20, or simple overflow 0x10. */


/*
 *	The boilerplate probe code.
 */

#ifdef HAVE_DEVLIST
struct netdev_entry el1_drv = {"3c501", el1_probe1, EL1_IO_EXTENT, netcard_portlist};
#else

__initfunc(int el1_probe(struct device *dev))
{
	int i;
	int base_addr = dev ? dev->base_addr : 0;

	if (base_addr > 0x1ff)	/* Check a single specified location. */
		return el1_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, EL1_IO_EXTENT))
			continue;
		if (el1_probe1(dev, ioaddr) == 0)
			return 0;
	}

	return ENODEV;
}
#endif

/*
 *	The actual probe.
 */

__initfunc(static int el1_probe1(struct device *dev, int ioaddr))
{
	const char *mname;		/* Vendor name */
	unsigned char station_addr[6];
	int autoirq = 0;
	int i;

	/*
	 *	Read the station address PROM data from the special port.
	 */

	for (i = 0; i < 6; i++)
	{
		outw(i, ioaddr + EL1_DATAPTR);
		station_addr[i] = inb(ioaddr + EL1_SAPROM);
	}
	/*
	 *	Check the first three octets of the S.A. for 3Com's prefix, or
	 *	for the Sager NP943 prefix.
	 */

	if (station_addr[0] == 0x02  &&  station_addr[1] == 0x60
		&& station_addr[2] == 0x8c)
	{
		mname = "3c501";
	} else if (station_addr[0] == 0x00  &&  station_addr[1] == 0x80
	&& station_addr[2] == 0xC8)
	{
		mname = "NP943";
    	}
    	else
		return ENODEV;

	/*
	 *	Grab the region so we can find the another board if autoIRQ fails.
	 */

	request_region(ioaddr, EL1_IO_EXTENT,"3c501");

	/*
	 *	We auto-IRQ by shutting off the interrupt line and letting it float
	 *	high.
	 */

	if (dev->irq < 2)
	{
		autoirq_setup(2);
		inb(RX_STATUS);		/* Clear pending interrupts. */
		inb(TX_STATUS);
		outb(AX_LOOP + 1, AX_CMD);

		outb(0x00, AX_CMD);

		autoirq = autoirq_report(1);

		if (autoirq == 0)
		{
			printk("%s probe at %#x failed to detect IRQ line.\n",
				mname, ioaddr);
			return EAGAIN;
		}
	}

	outb(AX_RESET+AX_LOOP, AX_CMD);			/* Loopback mode. */
	dev->base_addr = ioaddr;
	memcpy(dev->dev_addr, station_addr, ETH_ALEN);

	if (dev->mem_start & 0xf)
		el_debug = dev->mem_start & 0x7;
	if (autoirq)
		dev->irq = autoirq;

	printk("%s: %s EtherLink at %#lx, using %sIRQ %d.\n", dev->name, mname, dev->base_addr,
			autoirq ? "auto":"assigned ", dev->irq);

#ifdef CONFIG_IP_MULTICAST
	printk("WARNING: Use of the 3c501 in a multicast kernel is NOT recommended.\n");
#endif

	if (el_debug)
		printk("%s", version);

	/*
	 *	Initialize the device structure.
	 */

	dev->priv = kmalloc(sizeof(struct net_local), GFP_KERNEL);
	if (dev->priv == NULL)
		return -ENOMEM;
	memset(dev->priv, 0, sizeof(struct net_local));

	/*
	 *	The EL1-specific entries in the device structure.
	 */

	dev->open = &el_open;
	dev->hard_start_xmit = &el_start_xmit;
	dev->stop = &el1_close;
	dev->get_stats = &el1_get_stats;
	dev->set_multicast_list = &set_multicast_list;

	/*
	 *	Setup the generic properties
	 */

	ether_setup(dev);

	return 0;
}

/*
 *	Open/initialize the board.
 */

static int el_open(struct device *dev)
{
	int ioaddr = dev->base_addr;

	if (el_debug > 2)
		printk("%s: Doing el_open()...", dev->name);

	if (request_irq(dev->irq, &el_interrupt, 0, "3c501", dev))
		return -EAGAIN;

	el_reset(dev);

	dev->start = 1;

	outb(AX_RX, AX_CMD);	/* Aux control, irq and receive enabled */
	MOD_INC_USE_COUNT;
	return 0;
}

static int el_start_xmit(struct sk_buff *skb, struct device *dev)
{
	struct net_local *lp = (struct net_local *)dev->priv;
	int ioaddr = dev->base_addr;
	unsigned long flags;

	if(dev->interrupt)		/* May be unloading, don't stamp on */
		return 1;		/* the packet buffer this time      */

	if (dev->tbusy)
	{
		if (jiffies - dev->trans_start < 20)
		{
			if (el_debug > 2)
				printk(" transmitter busy, deferred.\n");
			return 1;
		}
		if (el_debug)
			printk ("%s: transmit timed out, txsr %#2x axsr=%02x rxsr=%02x.\n",
				dev->name, inb(TX_STATUS), inb(AX_STATUS), inb(RX_STATUS));
		lp->stats.tx_errors++;
		outb(TX_NORM, TX_CMD);
		outb(RX_NORM, RX_CMD);
		outb(AX_OFF, AX_CMD);	/* Just trigger a false interrupt. */
		outb(AX_RX, AX_CMD);	/* Aux control, irq and receive enabled */
		dev->tbusy = 0;
		dev->trans_start = jiffies;
	}

	save_flags(flags);

	/*
	 *	Avoid incoming interrupts between us flipping tbusy and flipping
	 *	mode as the driver assumes tbusy is a faithful indicator of card
	 *	state
	 */

	cli();

	/*
	 *	Avoid timer-based retransmission conflicts.
	 */

	if (test_and_set_bit(0, (void*)&dev->tbusy) != 0)
	{
		restore_flags(flags);
		printk("%s: Transmitter access conflict.\n", dev->name);
	}
	else
	{
		int gp_start = 0x800 - (ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN);
		unsigned char *buf = skb->data;

load_it_again_sam:
		lp->tx_pkt_start = gp_start;
    		lp->collisions = 0;

    		lp->stats.tx_bytes += skb->len;

		/*
		 *	Command mode with status cleared should [in theory]
		 *	mean no more interrupts can be pending on the card.
		 */

#ifdef BLOCKOUT_1
		disable_irq(dev->irq);
#endif
		outb_p(AX_SYS, AX_CMD);
		inb_p(RX_STATUS);
		inb_p(TX_STATUS);

		lp->loading=1;

		/*
		 *	Turn interrupts back on while we spend a pleasant afternoon
		 *	loading bytes into the board
		 */

		restore_flags(flags);
		outw(0x00, RX_BUF_CLR);		/* Set rx packet area to 0. */
		outw(gp_start, GP_LOW);		/* aim - packet will be loaded into buffer start */
		outsb(DATAPORT,buf,skb->len);	/* load buffer (usual thing each byte increments the pointer) */
		outw(gp_start, GP_LOW);		/* the board reuses the same register */
#ifndef BLOCKOUT_1
		if(lp->loading==2)		/* A receive upset our load, despite our best efforts */
		{
			if(el_debug>2)
				printk("%s: burped during tx load.\n", dev->name);
			goto load_it_again_sam;	/* Sigh... */
		}
#endif
		outb(AX_XMIT, AX_CMD);		/* fire ... Trigger xmit.  */
		lp->loading=0;
#ifdef BLOCKOUT_1
		enable_irq(dev->irq);
#endif
		dev->trans_start = jiffies;
	}

	if (el_debug > 2)
		printk(" queued xmit.\n");
	dev_kfree_skb (skb);
	return 0;
}


/*
 *	The typical workload of the driver:
 *	Handle the ether interface interrupts.
 */

static void el_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct device *dev = dev_id;
	struct net_local *lp;
	int ioaddr;
	int axsr;			/* Aux. status reg. */

	if (dev == NULL  ||  dev->irq != irq)
	{
		printk ("3c501 driver: irq %d for unknown device.\n", irq);
		return;
	}

	ioaddr = dev->base_addr;
	lp = (struct net_local *)dev->priv;

	/*
	 *	What happened ?
	 */

	axsr = inb(AX_STATUS);

	/*
	 *	Log it
	 */

	if (el_debug > 3)
		printk("%s: el_interrupt() aux=%#02x", dev->name, axsr);
	if (dev->interrupt)
		printk("%s: Reentering the interrupt driver!\n", dev->name);
	dev->interrupt = 1;
#ifndef BLOCKOUT_1
        if(lp->loading==1 && !dev->tbusy)
        	printk("%s: Inconsistent state loading while not in tx\n",
        		dev->name);
#endif
#ifdef BLOCKOUT_3
	lp->loading=2;		/* So we can spot loading interruptions */
#endif

	if (dev->tbusy)
	{

    		/*
    		 *	Board in transmit mode. May be loading. If we are
    		 *	loading we shouldn't have got this.
    		 */

		int txsr = inb(TX_STATUS);
#ifdef BLOCKOUT_2
		if(lp->loading==1)
		{
			if(el_debug > 2)
			{
				printk("%s: Interrupt while loading [", dev->name);
				printk(" txsr=%02x gp=%04x rp=%04x]\n", txsr, inw(GP_LOW),inw(RX_LOW));
			}
			lp->loading=2;		/* Force a reload */
			dev->interrupt = 0;
			return;
		}
#endif
		if (el_debug > 6)
			printk(" txsr=%02x gp=%04x rp=%04x", txsr, inw(GP_LOW),inw(RX_LOW));

		if ((axsr & 0x80) && (txsr & TX_READY) == 0)
		{
			/*
			 *	FIXME: is there a logic to whether to keep on trying or
			 *	reset immediately ?
			 */
			if(el_debug>1)
				printk("%s: Unusual interrupt during Tx, txsr=%02x axsr=%02x"
			  		" gp=%03x rp=%03x.\n", dev->name, txsr, axsr,
			inw(ioaddr + EL1_DATAPTR), inw(ioaddr + EL1_RXPTR));
			dev->tbusy = 0;
			mark_bh(NET_BH);
		}
		else if (txsr & TX_16COLLISIONS)
		{
			/*
			 *	Timed out
			 */
			if (el_debug)
				printk("%s: Transmit failed 16 times, Ethernet jammed?\n",dev->name);
			outb(AX_SYS, AX_CMD);
			lp->stats.tx_aborted_errors++;
		}
		else if (txsr & TX_COLLISION)
		{
			/*
			 *	Retrigger xmit.
			 */

			if (el_debug > 6)
				printk(" retransmitting after a collision.\n");
			/*
			 *	Poor little chip can't reset its own start pointer
			 */

			outb(AX_SYS, AX_CMD);
			outw(lp->tx_pkt_start, GP_LOW);
			outb(AX_XMIT, AX_CMD);
			lp->stats.collisions++;
			dev->interrupt = 0;
			return;
		}
		else
		{
			/*
			 *	It worked.. we will now fall through and receive
			 */
			lp->stats.tx_packets++;
			if (el_debug > 6)
				printk(" Tx succeeded %s\n",
		       			(txsr & TX_RDY) ? "." : "but tx is busy!");
			/*
			 *	This is safe the interrupt is atomic WRT itself.
			 */

			dev->tbusy = 0;
			mark_bh(NET_BH);	/* In case more to transmit */
		}
	}
	else
	{
    		/*
    		 *	In receive mode.
    		 */

		int rxsr = inb(RX_STATUS);
		if (el_debug > 5)
			printk(" rxsr=%02x txsr=%02x rp=%04x", rxsr, inb(TX_STATUS),inw(RX_LOW));
		/*
		 *	Just reading rx_status fixes most errors.
		 */
		if (rxsr & RX_MISSED)
			lp->stats.rx_missed_errors++;
		else if (rxsr & RX_RUNT)
		{	/* Handled to avoid board lock-up. */
			lp->stats.rx_length_errors++;
			if (el_debug > 5)
				printk(" runt.\n");
		}
		else if (rxsr & RX_GOOD)
		{
			/*
			 *	Receive worked.
			 */
			el_receive(dev);
		}
		else
		{
			/*
			 *	Nothing?  Something is broken!
			 */
			if (el_debug > 2)
				printk("%s: No packet seen, rxsr=%02x **resetting 3c501***\n",
					dev->name, rxsr);
			el_reset(dev);
		}
		if (el_debug > 3)
			printk(".\n");
	}

	/*
	 *	Move into receive mode
	 */

	outb(AX_RX, AX_CMD);
	outw(0x00, RX_BUF_CLR);
	inb(RX_STATUS);		/* Be certain that interrupts are cleared. */
	inb(TX_STATUS);
	dev->interrupt = 0;
	return;
}


/*
 *	We have a good packet. Well, not really "good", just mostly not broken.
 *	We must check everything to see if it is good.
 */

static void el_receive(struct device *dev)
{
	struct net_local *lp = (struct net_local *)dev->priv;
	int ioaddr = dev->base_addr;
	int pkt_len;
	struct sk_buff *skb;

	pkt_len = inw(RX_LOW);

	if (el_debug > 4)
		printk(" el_receive %d.\n", pkt_len);

	if ((pkt_len < 60)  ||  (pkt_len > 1536))
	{
		if (el_debug)
			printk("%s: bogus packet, length=%d\n", dev->name, pkt_len);
		lp->stats.rx_over_errors++;
		return;
	}

	/*
	 *	Command mode so we can empty the buffer
	 */

	outb(AX_SYS, AX_CMD);
	skb = dev_alloc_skb(pkt_len+2);

	/*
	 *	Start of frame
	 */

	outw(0x00, GP_LOW);
	if (skb == NULL)
	{
		printk("%s: Memory squeeze, dropping packet.\n", dev->name);
		lp->stats.rx_dropped++;
		return;
	}
	else
	{
    		skb_reserve(skb,2);	/* Force 16 byte alignment */
		skb->dev = dev;
		/*
		 *	The read increments through the bytes. The interrupt
		 *	handler will fix the pointer when it returns to
		 *	receive mode.
		 */
		insb(DATAPORT, skb_put(skb,pkt_len), pkt_len);
		skb->protocol=eth_type_trans(skb,dev);
		netif_rx(skb);
		lp->stats.rx_packets++;
		lp->stats.rx_bytes+=pkt_len;
	}
	return;
}

static void  el_reset(struct device *dev)
{
	int ioaddr = dev->base_addr;

	if (el_debug> 2)
		printk("3c501 reset...");
	outb(AX_RESET, AX_CMD);		/* Reset the chip */
	outb(AX_LOOP, AX_CMD);		/* Aux control, irq and loopback enabled */
	{
		int i;
		for (i = 0; i < 6; i++)	/* Set the station address. */
			outb(dev->dev_addr[i], ioaddr + i);
	}

	outw(0, RX_BUF_CLR);		/* Set rx packet area to 0. */
	cli();				/* Avoid glitch on writes to CMD regs */
	outb(TX_NORM, TX_CMD);		/* tx irq on done, collision */
	outb(RX_NORM, RX_CMD);		/* Set Rx commands. */
	inb(RX_STATUS);			/* Clear status. */
	inb(TX_STATUS);
	dev->interrupt = 0;
	dev->tbusy = 0;
	sti();
}

static int el1_close(struct device *dev)
{
	int ioaddr = dev->base_addr;

	if (el_debug > 2)
		printk("%s: Shutting down Ethernet card at %#x.\n", dev->name, ioaddr);

	dev->tbusy = 1;
	dev->start = 0;

	/*
	 *	Free and disable the IRQ.
	 */

	free_irq(dev->irq, dev);
	outb(AX_RESET, AX_CMD);		/* Reset the chip */

	MOD_DEC_USE_COUNT;
	return 0;
}

static struct net_device_stats *el1_get_stats(struct device *dev)
{
	struct net_local *lp = (struct net_local *)dev->priv;
	return &lp->stats;
}

/*
 *	Set or clear the multicast filter for this adaptor.
 *			best-effort filtering.
 */

static void set_multicast_list(struct device *dev)
{
	int ioaddr = dev->base_addr;

	if(dev->flags&IFF_PROMISC)
	{
		outb(RX_PROM, RX_CMD);
		inb(RX_STATUS);
	}
	else if (dev->mc_list || dev->flags&IFF_ALLMULTI)
	{
		outb(RX_MULT, RX_CMD);	/* Multicast or all multicast is the same */
		inb(RX_STATUS);		/* Clear status. */
	}
	else
	{
		outb(RX_NORM, RX_CMD);
		inb(RX_STATUS);
	}
}

#ifdef MODULE

static char devicename[9] = { 0, };

static struct device dev_3c501 =
{
	devicename, /* device name is inserted by linux/drivers/net/net_init.c */
	0, 0, 0, 0,
	0x280, 5,
	0, 0, 0, NULL, el1_probe
};

static int io=0x280;
static int irq=5;
MODULE_PARM(io, "i");
MODULE_PARM(irq, "i");

int init_module(void)
{
	dev_3c501.irq=irq;
	dev_3c501.base_addr=io;
	if (register_netdev(&dev_3c501) != 0)
		return -EIO;
	return 0;
}

void cleanup_module(void)
{
	/*
	 *	No need to check MOD_IN_USE, as sys_delete_module() checks.
	 */

	unregister_netdev(&dev_3c501);

	/*
	 *	Free up the private structure, or leak memory :-)
	 */

	kfree(dev_3c501.priv);
	dev_3c501.priv = NULL;	/* gets re-allocated by el1_probe1 */

	/*
	 *	If we don't do this, we can't re-insmod it later.
	 */
	release_region(dev_3c501.base_addr, EL1_IO_EXTENT);
}

#endif /* MODULE */

/*
 * Local variables:
 *  compile-command: "gcc -D__KERNEL__ -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer  -m486 -c -o 3c501.o 3c501.c"
 *  kept-new-versions: 5
 * End:
 */