summaryrefslogtreecommitdiff
path: root/drivers/net/ethernet/dlink/de620.c
blob: 1c51a757611904dfbc5aa03c6c56113a5321496c (plain)
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
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
/*
 *	de620.c $Revision: 1.40 $ BETA
 *
 *
 *	Linux driver for the D-Link DE-620 Ethernet pocket adapter.
 *
 *	Portions (C) Copyright 1993, 1994 by Bjorn Ekwall <bj0rn@blox.se>
 *
 *	Based on adapter information gathered from DOS packetdriver
 *	sources from D-Link Inc:  (Special thanks to Henry Ngai of D-Link.)
 *		Portions (C) Copyright D-Link SYSTEM Inc. 1991, 1992
 *		Copyright, 1988, Russell Nelson, Crynwr Software
 *
 *	Adapted to the sample network driver core for linux,
 *	written by: Donald Becker <becker@super.org>
 *		(Now at <becker@scyld.com>)
 *
 *	Valuable assistance from:
 *		J. Joshua Kopper <kopper@rtsg.mot.com>
 *		Olav Kvittem <Olav.Kvittem@uninett.no>
 *		Germano Caronni <caronni@nessie.cs.id.ethz.ch>
 *		Jeremy Fitzhardinge <jeremy@suite.sw.oz.au>
 *
 *****************************************************************************/
/*
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation; either version 2, or (at your option)
 *	any later version.
 *
 *	This program is distributed in the hope that it will be useful,
 *	but WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *	GNU General Public License for more details.
 *
 *	You should have received a copy of the GNU General Public License
 *	along with this program; if not, write to the Free Software
 *	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *****************************************************************************/
static const char version[] =
	"de620.c: $Revision: 1.40 $,  Bjorn Ekwall <bj0rn@blox.se>\n";

/***********************************************************************
 *
 * "Tuning" section.
 *
 * Compile-time options: (see below for descriptions)
 * -DDE620_IO=0x378	(lpt1)
 * -DDE620_IRQ=7	(lpt1)
 * -DSHUTDOWN_WHEN_LOST
 * -DCOUNT_LOOPS
 * -DLOWSPEED
 * -DREAD_DELAY
 * -DWRITE_DELAY
 */

/*
 * This driver assumes that the printer port is a "normal",
 * dumb, uni-directional port!
 * If your port is "fancy" in any way, please try to set it to "normal"
 * with your BIOS setup.  I have no access to machines with bi-directional
 * ports, so I can't test such a driver :-(
 * (Yes, I _know_ it is possible to use DE620 with bidirectional ports...)
 *
 * There are some clones of DE620 out there, with different names.
 * If the current driver does not recognize a clone, try to change
 * the following #define to:
 *
 * #define DE620_CLONE 1
 */
#define DE620_CLONE 0

/*
 * If the adapter has problems with high speeds, enable this #define
 * otherwise full printerport speed will be attempted.
 *
 * You can tune the READ_DELAY/WRITE_DELAY below if you enable LOWSPEED
 *
#define LOWSPEED
 */

#ifndef READ_DELAY
#define READ_DELAY 100	/* adapter internal read delay in 100ns units */
#endif

#ifndef WRITE_DELAY
#define WRITE_DELAY 100	/* adapter internal write delay in 100ns units */
#endif

/*
 * Enable this #define if you want the adapter to do a "ifconfig down" on
 * itself when we have detected that something is possibly wrong with it.
 * The default behaviour is to retry with "adapter_init()" until success.
 * This should be used for debugging purposes only.
 *
#define SHUTDOWN_WHEN_LOST
 */

#ifdef LOWSPEED
/*
 * Enable this #define if you want to see debugging output that show how long
 * we have to wait before the DE-620 is ready for the next read/write/command.
 *
#define COUNT_LOOPS
 */
#endif

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/string.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>

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

/* Constant definitions for the DE-620 registers, commands and bits */
#include "de620.h"

typedef unsigned char byte;

/*******************************************************
 *                                                     *
 * Definition of D-Link DE-620 Ethernet Pocket adapter *
 * See also "de620.h"                                  *
 *                                                     *
 *******************************************************/
#ifndef DE620_IO /* Compile-time configurable */
#define DE620_IO 0x378
#endif

#ifndef DE620_IRQ /* Compile-time configurable */
#define DE620_IRQ	7
#endif

#define DATA_PORT	(dev->base_addr)
#define STATUS_PORT	(dev->base_addr + 1)
#define COMMAND_PORT	(dev->base_addr + 2)

#define RUNT 60		/* Too small Ethernet packet */
#define GIANT 1514	/* largest legal size packet, no fcs */

/*
 * Force media with insmod:
 *	insmod de620.o bnc=1
 * or
 *	insmod de620.o utp=1
 *
 * Force io and/or irq with insmod:
 *	insmod de620.o io=0x378 irq=7
 *
 * Make a clone skip the Ethernet-address range check:
 *	insmod de620.o clone=1
 */
static int bnc;
static int utp;
static int io  = DE620_IO;
static int irq = DE620_IRQ;
static int clone = DE620_CLONE;

static spinlock_t de620_lock;

module_param(bnc, int, 0);
module_param(utp, int, 0);
module_param(io, int, 0);
module_param(irq, int, 0);
module_param(clone, int, 0);
MODULE_PARM_DESC(bnc, "DE-620 set BNC medium (0-1)");
MODULE_PARM_DESC(utp, "DE-620 set UTP medium (0-1)");
MODULE_PARM_DESC(io, "DE-620 I/O base address,required");
MODULE_PARM_DESC(irq, "DE-620 IRQ number,required");
MODULE_PARM_DESC(clone, "Check also for non-D-Link DE-620 clones (0-1)");

/***********************************************
 *                                             *
 * Index to functions, as function prototypes. *
 *                                             *
 ***********************************************/

/*
 * Routines used internally. (See also "convenience macros.. below")
 */

/* Put in the device structure. */
static int	de620_open(struct net_device *);
static int	de620_close(struct net_device *);
static void	de620_set_multicast_list(struct net_device *);
static int	de620_start_xmit(struct sk_buff *, struct net_device *);

/* Dispatch from interrupts. */
static irqreturn_t de620_interrupt(int, void *);
static int	de620_rx_intr(struct net_device *);

/* Initialization */
static int	adapter_init(struct net_device *);
static int	read_eeprom(struct net_device *);


/*
 * D-Link driver variables:
 */
#define SCR_DEF NIBBLEMODE |INTON | SLEEP | AUTOTX
#define	TCR_DEF RXPB			/* not used: | TXSUCINT | T16INT */
#define DE620_RX_START_PAGE 12		/* 12 pages (=3k) reserved for tx */
#define DEF_NIC_CMD IRQEN | ICEN | DS1

static volatile byte	NIC_Cmd;
static volatile byte	next_rx_page;
static byte		first_rx_page;
static byte		last_rx_page;
static byte		EIPRegister;

static struct nic {
	byte	NodeID[6];
	byte	RAM_Size;
	byte	Model;
	byte	Media;
	byte	SCR;
} nic_data;

/**********************************************************
 *                                                        *
 * Convenience macros/functions for D-Link DE-620 adapter *
 *                                                        *
 **********************************************************/
#define de620_tx_buffs(dd) (inb(STATUS_PORT) & (TXBF0 | TXBF1))
#define de620_flip_ds(dd) NIC_Cmd ^= DS0 | DS1; outb(NIC_Cmd, COMMAND_PORT);

/* Check for ready-status, and return a nibble (high 4 bits) for data input */
#ifdef COUNT_LOOPS
static int tot_cnt;
#endif
static inline byte
de620_ready(struct net_device *dev)
{
	byte value;
	register short int cnt = 0;

	while ((((value = inb(STATUS_PORT)) & READY) == 0) && (cnt <= 1000))
		++cnt;

#ifdef COUNT_LOOPS
	tot_cnt += cnt;
#endif
	return value & 0xf0; /* nibble */
}

static inline void
de620_send_command(struct net_device *dev, byte cmd)
{
	de620_ready(dev);
	if (cmd == W_DUMMY)
		outb(NIC_Cmd, COMMAND_PORT);

	outb(cmd, DATA_PORT);

	outb(NIC_Cmd ^ CS0, COMMAND_PORT);
	de620_ready(dev);
	outb(NIC_Cmd, COMMAND_PORT);
}

static inline void
de620_put_byte(struct net_device *dev, byte value)
{
	/* The de620_ready() makes 7 loops, on the average, on a DX2/66 */
	de620_ready(dev);
	outb(value, DATA_PORT);
	de620_flip_ds(dev);
}

static inline byte
de620_read_byte(struct net_device *dev)
{
	byte value;

	/* The de620_ready() makes 7 loops, on the average, on a DX2/66 */
	value = de620_ready(dev); /* High nibble */
	de620_flip_ds(dev);
	value |= de620_ready(dev) >> 4; /* Low nibble */
	return value;
}

static inline void
de620_write_block(struct net_device *dev, byte *buffer, int count, int pad)
{
#ifndef LOWSPEED
	byte uflip = NIC_Cmd ^ (DS0 | DS1);
	byte dflip = NIC_Cmd;
#else /* LOWSPEED */
#ifdef COUNT_LOOPS
	int bytes = count;
#endif /* COUNT_LOOPS */
#endif /* LOWSPEED */

#ifdef LOWSPEED
#ifdef COUNT_LOOPS
	tot_cnt = 0;
#endif /* COUNT_LOOPS */
	/* No further optimization useful, the limit is in the adapter. */
	for ( ; count > 0; --count, ++buffer) {
		de620_put_byte(dev,*buffer);
	}
	for ( count = pad ; count > 0; --count, ++buffer) {
		de620_put_byte(dev, 0);
	}
	de620_send_command(dev,W_DUMMY);
#ifdef COUNT_LOOPS
	/* trial debug output: loops per byte in de620_ready() */
	printk("WRITE(%d)\n", tot_cnt/((bytes?bytes:1)));
#endif /* COUNT_LOOPS */
#else /* not LOWSPEED */
	for ( ; count > 0; count -=2) {
		outb(*buffer++, DATA_PORT);
		outb(uflip, COMMAND_PORT);
		outb(*buffer++, DATA_PORT);
		outb(dflip, COMMAND_PORT);
	}
	de620_send_command(dev,W_DUMMY);
#endif /* LOWSPEED */
}

static inline void
de620_read_block(struct net_device *dev, byte *data, int count)
{
#ifndef LOWSPEED
	byte value;
	byte uflip = NIC_Cmd ^ (DS0 | DS1);
	byte dflip = NIC_Cmd;
#else /* LOWSPEED */
#ifdef COUNT_LOOPS
	int bytes = count;

	tot_cnt = 0;
#endif /* COUNT_LOOPS */
#endif /* LOWSPEED */

#ifdef LOWSPEED
	/* No further optimization useful, the limit is in the adapter. */
	while (count-- > 0) {
		*data++ = de620_read_byte(dev);
		de620_flip_ds(dev);
	}
#ifdef COUNT_LOOPS
	/* trial debug output: loops per byte in de620_ready() */
	printk("READ(%d)\n", tot_cnt/(2*(bytes?bytes:1)));
#endif /* COUNT_LOOPS */
#else /* not LOWSPEED */
	while (count-- > 0) {
		value = inb(STATUS_PORT) & 0xf0; /* High nibble */
		outb(uflip, COMMAND_PORT);
		*data++ = value | inb(STATUS_PORT) >> 4; /* Low nibble */
		outb(dflip , COMMAND_PORT);
	}
#endif /* LOWSPEED */
}

static inline void
de620_set_delay(struct net_device *dev)
{
	de620_ready(dev);
	outb(W_DFR, DATA_PORT);
	outb(NIC_Cmd ^ CS0, COMMAND_PORT);

	de620_ready(dev);
#ifdef LOWSPEED
	outb(WRITE_DELAY, DATA_PORT);
#else
	outb(0, DATA_PORT);
#endif
	de620_flip_ds(dev);

	de620_ready(dev);
#ifdef LOWSPEED
	outb(READ_DELAY, DATA_PORT);
#else
	outb(0, DATA_PORT);
#endif
	de620_flip_ds(dev);
}

static inline void
de620_set_register(struct net_device *dev, byte reg, byte value)
{
	de620_ready(dev);
	outb(reg, DATA_PORT);
	outb(NIC_Cmd ^ CS0, COMMAND_PORT);

	de620_put_byte(dev, value);
}

static inline byte
de620_get_register(struct net_device *dev, byte reg)
{
	byte value;

	de620_send_command(dev,reg);
	value = de620_read_byte(dev);
	de620_send_command(dev,W_DUMMY);

	return value;
}

/*********************************************************************
 *
 * Open/initialize the board.
 *
 * 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 a non-reboot way to recover if something goes wrong.
 *
 */
static int de620_open(struct net_device *dev)
{
	int ret = request_irq(dev->irq, de620_interrupt, 0, dev->name, dev);
	if (ret) {
		printk (KERN_ERR "%s: unable to get IRQ %d\n", dev->name, dev->irq);
		return ret;
	}

	if (adapter_init(dev)) {
		ret = -EIO;
		goto out_free_irq;
	}

	netif_start_queue(dev);
	return 0;

out_free_irq:
	free_irq(dev->irq, dev);
	return ret;
}

/************************************************
 *
 * The inverse routine to de620_open().
 *
 */

static int de620_close(struct net_device *dev)
{
	netif_stop_queue(dev);
	/* disable recv */
	de620_set_register(dev, W_TCR, RXOFF);
	free_irq(dev->irq, dev);
	return 0;
}

/*********************************************
 *
 * Set or clear the multicast filter for this adaptor.
 * (no real multicast implemented for the DE-620, but she can be promiscuous...)
 *
 */

static void de620_set_multicast_list(struct net_device *dev)
{
	if (!netdev_mc_empty(dev) || dev->flags&(IFF_ALLMULTI|IFF_PROMISC))
	{ /* Enable promiscuous mode */
		de620_set_register(dev, W_TCR, (TCR_DEF & ~RXPBM) | RXALL);
	}
	else
	{ /* Disable promiscuous mode, use normal mode */
		de620_set_register(dev, W_TCR, TCR_DEF);
	}
}

/*******************************************************
 *
 * Handle timeouts on transmit
 */

static void de620_timeout(struct net_device *dev)
{
	printk(KERN_WARNING "%s: transmit timed out, %s?\n", dev->name, "network cable problem");
	/* Restart the adapter. */
	if (!adapter_init(dev)) /* maybe close it */
		netif_wake_queue(dev);
}

/*******************************************************
 *
 * Copy a buffer to the adapter transmit page memory.
 * Start sending.
 */
static int de620_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	unsigned long flags;
	int len;
	byte *buffer = skb->data;
	byte using_txbuf;

	using_txbuf = de620_tx_buffs(dev); /* Peek at the adapter */

	netif_stop_queue(dev);


	if ((len = skb->len) < RUNT)
		len = RUNT;
	if (len & 1) /* send an even number of bytes */
		++len;

	/* Start real output */

	spin_lock_irqsave(&de620_lock, flags);
	pr_debug("de620_start_xmit: len=%d, bufs 0x%02x\n",
		(int)skb->len, using_txbuf);

	/* select a free tx buffer. if there is one... */
	switch (using_txbuf) {
	default: /* both are free: use TXBF0 */
	case TXBF1: /* use TXBF0 */
		de620_send_command(dev,W_CR | RW0);
		using_txbuf |= TXBF0;
		break;

	case TXBF0: /* use TXBF1 */
		de620_send_command(dev,W_CR | RW1);
		using_txbuf |= TXBF1;
		break;

	case (TXBF0 | TXBF1): /* NONE!!! */
		printk(KERN_WARNING "%s: No tx-buffer available!\n", dev->name);
		spin_unlock_irqrestore(&de620_lock, flags);
		return NETDEV_TX_BUSY;
	}
	de620_write_block(dev, buffer, skb->len, len-skb->len);

	if(!(using_txbuf == (TXBF0 | TXBF1)))
		netif_wake_queue(dev);

	dev->stats.tx_packets++;
	spin_unlock_irqrestore(&de620_lock, flags);
	dev_kfree_skb (skb);
	return NETDEV_TX_OK;
}

/*****************************************************
 *
 * Handle the network interface interrupts.
 *
 */
static irqreturn_t
de620_interrupt(int irq_in, void *dev_id)
{
	struct net_device *dev = dev_id;
	byte irq_status;
	int bogus_count = 0;
	int again = 0;

	spin_lock(&de620_lock);

	/* Read the status register (_not_ the status port) */
	irq_status = de620_get_register(dev, R_STS);

	pr_debug("de620_interrupt (%2.2X)\n", irq_status);

	if (irq_status & RXGOOD) {
		do {
			again = de620_rx_intr(dev);
			pr_debug("again=%d\n", again);
		}
		while (again && (++bogus_count < 100));
	}

	if(de620_tx_buffs(dev) != (TXBF0 | TXBF1))
		netif_wake_queue(dev);

	spin_unlock(&de620_lock);
	return IRQ_HANDLED;
}

/**************************************
 *
 * Get a packet from the adapter
 *
 * Send it "upstairs"
 *
 */
static int de620_rx_intr(struct net_device *dev)
{
	struct header_buf {
		byte		status;
		byte		Rx_NextPage;
		unsigned short	Rx_ByteCount;
	} header_buf;
	struct sk_buff *skb;
	int size;
	byte *buffer;
	byte pagelink;
	byte curr_page;

	pr_debug("de620_rx_intr: next_rx_page = %d\n", next_rx_page);

	/* Tell the adapter that we are going to read data, and from where */
	de620_send_command(dev, W_CR | RRN);
	de620_set_register(dev, W_RSA1, next_rx_page);
	de620_set_register(dev, W_RSA0, 0);

	/* Deep breath, and away we goooooo */
	de620_read_block(dev, (byte *)&header_buf, sizeof(struct header_buf));
	pr_debug("page status=0x%02x, nextpage=%d, packetsize=%d\n",
		header_buf.status, header_buf.Rx_NextPage,
		header_buf.Rx_ByteCount);

	/* Plausible page header? */
	pagelink = header_buf.Rx_NextPage;
	if ((pagelink < first_rx_page) || (last_rx_page < pagelink)) {
		/* Ouch... Forget it! Skip all and start afresh... */
		printk(KERN_WARNING "%s: Ring overrun? Restoring...\n", dev->name);
		/* You win some, you lose some. And sometimes plenty... */
		adapter_init(dev);
		netif_wake_queue(dev);
		dev->stats.rx_over_errors++;
		return 0;
	}

	/* OK, this look good, so far. Let's see if it's consistent... */
	/* Let's compute the start of the next packet, based on where we are */
	pagelink = next_rx_page +
		((header_buf.Rx_ByteCount + (4 - 1 + 0x100)) >> 8);

	/* Are we going to wrap around the page counter? */
	if (pagelink > last_rx_page)
		pagelink -= (last_rx_page - first_rx_page + 1);

	/* Is the _computed_ next page number equal to what the adapter says? */
	if (pagelink != header_buf.Rx_NextPage) {
		/* Naah, we'll skip this packet. Probably bogus data as well */
		printk(KERN_WARNING "%s: Page link out of sync! Restoring...\n", dev->name);
		next_rx_page = header_buf.Rx_NextPage; /* at least a try... */
		de620_send_command(dev, W_DUMMY);
		de620_set_register(dev, W_NPRF, next_rx_page);
		dev->stats.rx_over_errors++;
		return 0;
	}
	next_rx_page = pagelink;

	size = header_buf.Rx_ByteCount - 4;
	if ((size < RUNT) || (GIANT < size)) {
		printk(KERN_WARNING "%s: Illegal packet size: %d!\n", dev->name, size);
	}
	else { /* Good packet? */
		skb = dev_alloc_skb(size+2);
		if (skb == NULL) { /* Yeah, but no place to put it... */
			printk(KERN_WARNING "%s: Couldn't allocate a sk_buff of size %d.\n", dev->name, size);
			dev->stats.rx_dropped++;
		}
		else { /* Yep! Go get it! */
			skb_reserve(skb,2);	/* Align */
			/* skb->data points to the start of sk_buff data area */
			buffer = skb_put(skb,size);
			/* copy the packet into the buffer */
			de620_read_block(dev, buffer, size);
			pr_debug("Read %d bytes\n", size);
			skb->protocol=eth_type_trans(skb,dev);
			netif_rx(skb); /* deliver it "upstairs" */
			/* count all receives */
			dev->stats.rx_packets++;
			dev->stats.rx_bytes += size;
		}
	}

	/* Let's peek ahead to see if we have read the last current packet */
	/* NOTE! We're _not_ checking the 'EMPTY'-flag! This seems better... */
	curr_page = de620_get_register(dev, R_CPR);
	de620_set_register(dev, W_NPRF, next_rx_page);
	pr_debug("next_rx_page=%d CPR=%d\n", next_rx_page, curr_page);

	return next_rx_page != curr_page; /* That was slightly tricky... */
}

/*********************************************
 *
 * Reset the adapter to a known state
 *
 */
static int adapter_init(struct net_device *dev)
{
	int i;
	static int was_down;

	if ((nic_data.Model == 3) || (nic_data.Model == 0)) { /* CT */
		EIPRegister = NCTL0;
		if (nic_data.Media != 1)
			EIPRegister |= NIS0;	/* not BNC */
	}
	else if (nic_data.Model == 2) { /* UTP */
		EIPRegister = NCTL0 | NIS0;
	}

	if (utp)
		EIPRegister = NCTL0 | NIS0;
	if (bnc)
		EIPRegister = NCTL0;

	de620_send_command(dev, W_CR | RNOP | CLEAR);
	de620_send_command(dev, W_CR | RNOP);

	de620_set_register(dev, W_SCR, SCR_DEF);
	/* disable recv to wait init */
	de620_set_register(dev, W_TCR, RXOFF);

	/* Set the node ID in the adapter */
	for (i = 0; i < 6; ++i) { /* W_PARn = 0xaa + n */
		de620_set_register(dev, W_PAR0 + i, dev->dev_addr[i]);
	}

	de620_set_register(dev, W_EIP, EIPRegister);

	next_rx_page = first_rx_page = DE620_RX_START_PAGE;
	if (nic_data.RAM_Size)
		last_rx_page = nic_data.RAM_Size - 1;
	else /* 64k RAM */
		last_rx_page = 255;

	de620_set_register(dev, W_SPR, first_rx_page); /* Start Page Register*/
	de620_set_register(dev, W_EPR, last_rx_page);  /* End Page Register */
	de620_set_register(dev, W_CPR, first_rx_page);/*Current Page Register*/
	de620_send_command(dev, W_NPR | first_rx_page); /* Next Page Register*/
	de620_send_command(dev, W_DUMMY);
	de620_set_delay(dev);

	/* Final sanity check: Anybody out there? */
	/* Let's hope some bits from the statusregister make a good check */
#define CHECK_MASK (  0 | TXSUC |  T16  |  0  | RXCRC | RXSHORT |  0  |  0  )
#define CHECK_OK   (  0 |   0   |  0    |  0  |   0   |   0     |  0  |  0  )
        /* success:   X     0      0       X      0       0        X     X  */
        /* ignore:   EEDI                RXGOOD                   COLS  LNKS*/

	if (((i = de620_get_register(dev, R_STS)) & CHECK_MASK) != CHECK_OK) {
		printk(KERN_ERR "%s: Something has happened to the DE-620!  Please check it"
#ifdef SHUTDOWN_WHEN_LOST
			" and do a new ifconfig"
#endif
			"! (%02x)\n", dev->name, i);
#ifdef SHUTDOWN_WHEN_LOST
		/* Goodbye, cruel world... */
		dev->flags &= ~IFF_UP;
		de620_close(dev);
#endif
		was_down = 1;
		return 1; /* failed */
	}
	if (was_down) {
		printk(KERN_WARNING "%s: Thanks, I feel much better now!\n", dev->name);
		was_down = 0;
	}

	/* All OK, go ahead... */
	de620_set_register(dev, W_TCR, TCR_DEF);

	return 0; /* all ok */
}

static const struct net_device_ops de620_netdev_ops = {
	.ndo_open 		= de620_open,
	.ndo_stop 		= de620_close,
	.ndo_start_xmit 	= de620_start_xmit,
	.ndo_tx_timeout 	= de620_timeout,
	.ndo_set_multicast_list = de620_set_multicast_list,
	.ndo_change_mtu		= eth_change_mtu,
	.ndo_set_mac_address 	= eth_mac_addr,
	.ndo_validate_addr	= eth_validate_addr,
};

/******************************************************************************
 *
 * Only start-up code below
 *
 */
/****************************************
 *
 * Check if there is a DE-620 connected
 */
struct net_device * __init de620_probe(int unit)
{
	byte checkbyte = 0xa5;
	struct net_device *dev;
	int err = -ENOMEM;
	int i;

	dev = alloc_etherdev(0);
	if (!dev)
		goto out;

	spin_lock_init(&de620_lock);

	/*
	 * This is where the base_addr and irq gets set.
	 * Tunable at compile-time and insmod-time
	 */
	dev->base_addr = io;
	dev->irq       = irq;

	/* allow overriding parameters on command line */
	if (unit >= 0) {
		sprintf(dev->name, "eth%d", unit);
		netdev_boot_setup_check(dev);
	}

	pr_debug("%s", version);

	printk(KERN_INFO "D-Link DE-620 pocket adapter");

	if (!request_region(dev->base_addr, 3, "de620")) {
		printk(" io 0x%3lX, which is busy.\n", dev->base_addr);
		err = -EBUSY;
		goto out1;
	}

	/* Initially, configure basic nibble mode, so we can read the EEPROM */
	NIC_Cmd = DEF_NIC_CMD;
	de620_set_register(dev, W_EIP, EIPRegister);

	/* Anybody out there? */
	de620_set_register(dev, W_CPR, checkbyte);
	checkbyte = de620_get_register(dev, R_CPR);

	if ((checkbyte != 0xa5) || (read_eeprom(dev) != 0)) {
		printk(" not identified in the printer port\n");
		err = -ENODEV;
		goto out2;
	}

	/* else, got it! */
	dev->dev_addr[0] = nic_data.NodeID[0];
	for (i = 1; i < ETH_ALEN; i++) {
		dev->dev_addr[i] = nic_data.NodeID[i];
		dev->broadcast[i] = 0xff;
	}

	printk(", Ethernet Address: %pM", dev->dev_addr);

	printk(" (%dk RAM,",
		(nic_data.RAM_Size) ? (nic_data.RAM_Size >> 2) : 64);

	if (nic_data.Media == 1)
		printk(" BNC)\n");
	else
		printk(" UTP)\n");

	dev->netdev_ops = &de620_netdev_ops;
	dev->watchdog_timeo	= HZ*2;

	/* base_addr and irq are already set, see above! */

	/* dump eeprom */
	pr_debug("\nEEPROM contents:\n"
		"RAM_Size = 0x%02X\n"
		"NodeID = %pM\n"
		"Model = %d\n"
		"Media = %d\n"
		"SCR = 0x%02x\n", nic_data.RAM_Size, nic_data.NodeID,
		nic_data.Model, nic_data.Media, nic_data.SCR);

	err = register_netdev(dev);
	if (err)
		goto out2;
	return dev;

out2:
	release_region(dev->base_addr, 3);
out1:
	free_netdev(dev);
out:
	return ERR_PTR(err);
}

/**********************************
 *
 * Read info from on-board EEPROM
 *
 * Note: Bitwise serial I/O to/from the EEPROM vi the status _register_!
 */
#define sendit(dev,data) de620_set_register(dev, W_EIP, data | EIPRegister);

static unsigned short __init ReadAWord(struct net_device *dev, int from)
{
	unsigned short data;
	int nbits;

	/* cs   [__~~] SET SEND STATE */
	/* di   [____]                */
	/* sck  [_~~_]                */
	sendit(dev, 0); sendit(dev, 1); sendit(dev, 5); sendit(dev, 4);

	/* Send the 9-bit address from where we want to read the 16-bit word */
	for (nbits = 9; nbits > 0; --nbits, from <<= 1) {
		if (from & 0x0100) { /* bit set? */
			/* cs    [~~~~] SEND 1 */
			/* di    [~~~~]        */
			/* sck   [_~~_]        */
			sendit(dev, 6); sendit(dev, 7); sendit(dev, 7); sendit(dev, 6);
		}
		else {
			/* cs    [~~~~] SEND 0 */
			/* di    [____]        */
			/* sck   [_~~_]        */
			sendit(dev, 4); sendit(dev, 5); sendit(dev, 5); sendit(dev, 4);
		}
	}

	/* Shift in the 16-bit word. The bits appear serially in EEDI (=0x80) */
	for (data = 0, nbits = 16; nbits > 0; --nbits) {
		/* cs    [~~~~] SEND 0 */
		/* di    [____]        */
		/* sck   [_~~_]        */
		sendit(dev, 4); sendit(dev, 5); sendit(dev, 5); sendit(dev, 4);
		data = (data << 1) | ((de620_get_register(dev, R_STS) & EEDI) >> 7);
	}
	/* cs    [____] RESET SEND STATE */
	/* di    [____]                  */
	/* sck   [_~~_]                  */
	sendit(dev, 0); sendit(dev, 1); sendit(dev, 1); sendit(dev, 0);

	return data;
}

static int __init read_eeprom(struct net_device *dev)
{
	unsigned short wrd;

	/* D-Link Ethernet addresses are in the series  00:80:c8:7X:XX:XX:XX */
	wrd = ReadAWord(dev, 0x1aa);	/* bytes 0 + 1 of NodeID */
	if (!clone && (wrd != htons(0x0080))) /* Valid D-Link ether sequence? */
		return -1; /* Nope, not a DE-620 */
	nic_data.NodeID[0] = wrd & 0xff;
	nic_data.NodeID[1] = wrd >> 8;

	wrd = ReadAWord(dev, 0x1ab);	/* bytes 2 + 3 of NodeID */
	if (!clone && ((wrd & 0xff) != 0xc8)) /* Valid D-Link ether sequence? */
		return -1; /* Nope, not a DE-620 */
	nic_data.NodeID[2] = wrd & 0xff;
	nic_data.NodeID[3] = wrd >> 8;

	wrd = ReadAWord(dev, 0x1ac);	/* bytes 4 + 5 of NodeID */
	nic_data.NodeID[4] = wrd & 0xff;
	nic_data.NodeID[5] = wrd >> 8;

	wrd = ReadAWord(dev, 0x1ad);	/* RAM size in pages (256 bytes). 0 = 64k */
	nic_data.RAM_Size = (wrd >> 8);

	wrd = ReadAWord(dev, 0x1ae);	/* hardware model (CT = 3) */
	nic_data.Model = (wrd & 0xff);

	wrd = ReadAWord(dev, 0x1af); /* media (indicates BNC/UTP) */
	nic_data.Media = (wrd & 0xff);

	wrd = ReadAWord(dev, 0x1a8); /* System Configuration Register */
	nic_data.SCR = (wrd >> 8);

	return 0; /* no errors */
}

/******************************************************************************
 *
 * Loadable module skeleton
 *
 */
#ifdef MODULE
static struct net_device *de620_dev;

int __init init_module(void)
{
	de620_dev = de620_probe(-1);
	if (IS_ERR(de620_dev))
		return PTR_ERR(de620_dev);
	return 0;
}

void cleanup_module(void)
{
	unregister_netdev(de620_dev);
	release_region(de620_dev->base_addr, 3);
	free_netdev(de620_dev);
}
#endif /* MODULE */
MODULE_LICENSE("GPL");