aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/tulip/xircom_cb.c
blob: 13c8703ecb9f0794e4ca718797a8ea0ea3ef8ed9 (plain) (blame)
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
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
/*
 * xircom_cb: A driver for the (tulip-like) Xircom Cardbus ethernet cards
 *
 * This software is (C) by the respective authors, and licensed under the GPL
 * License.
 *
 * Written by Arjan van de Ven for Red Hat, Inc.
 * Based on work by Jeff Garzik, Doug Ledford and Donald Becker
 *
 *  	This software may be used and distributed according to the terms
 *      of the GNU General Public License, incorporated herein by reference.
 *
 *
 * 	$Id: xircom_cb.c,v 1.33 2001/03/19 14:02:07 arjanv Exp $
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/ethtool.h>
#include <linux/bitops.h>

#include <asm/uaccess.h>
#include <asm/io.h>
#ifdef CONFIG_NET_POLL_CONTROLLER
#include <asm/irq.h>
#endif

#ifdef DEBUG
#define enter(x)   printk("Enter: %s, %s line %i\n",x,__FILE__,__LINE__)
#define leave(x)   printk("Leave: %s, %s line %i\n",x,__FILE__,__LINE__)
#else
#define enter(x)   do {} while (0)
#define leave(x)   do {} while (0)
#endif


MODULE_DESCRIPTION("Xircom Cardbus ethernet driver");
MODULE_AUTHOR("Arjan van de Ven <arjanv@redhat.com>");
MODULE_LICENSE("GPL");



/* IO registers on the card, offsets */
#define CSR0	0x00
#define CSR1	0x08
#define CSR2	0x10
#define CSR3	0x18
#define CSR4	0x20
#define CSR5	0x28
#define CSR6	0x30
#define CSR7	0x38
#define CSR8	0x40
#define CSR9	0x48
#define CSR10	0x50
#define CSR11	0x58
#define CSR12	0x60
#define CSR13	0x68
#define CSR14	0x70
#define CSR15	0x78
#define CSR16	0x80

/* PCI registers */
#define PCI_POWERMGMT 	0x40

/* Offsets of the buffers within the descriptor pages, in bytes */

#define NUMDESCRIPTORS 4

static int bufferoffsets[NUMDESCRIPTORS] = {128,2048,4096,6144};


struct xircom_private {
	/* Send and receive buffers, kernel-addressable and dma addressable forms */

	__le32 *rx_buffer;
	__le32 *tx_buffer;

	dma_addr_t rx_dma_handle;
	dma_addr_t tx_dma_handle;

	struct sk_buff *tx_skb[4];

	unsigned long io_port;
	int open;

	/* transmit_used is the rotating counter that indicates which transmit
	   descriptor has to be used next */
	int transmit_used;

	/* Spinlock to serialize register operations.
	   It must be helt while manipulating the following registers:
	   CSR0, CSR6, CSR7, CSR9, CSR10, CSR15
	 */
	spinlock_t lock;


	struct pci_dev *pdev;
	struct net_device *dev;
	struct net_device_stats stats;
};


/* Function prototypes */
static int xircom_probe(struct pci_dev *pdev, const struct pci_device_id *id);
static void xircom_remove(struct pci_dev *pdev);
static irqreturn_t xircom_interrupt(int irq, void *dev_instance);
static int xircom_start_xmit(struct sk_buff *skb, struct net_device *dev);
static int xircom_open(struct net_device *dev);
static int xircom_close(struct net_device *dev);
static void xircom_up(struct xircom_private *card);
static struct net_device_stats *xircom_get_stats(struct net_device *dev);
#ifdef CONFIG_NET_POLL_CONTROLLER
static void xircom_poll_controller(struct net_device *dev);
#endif

static void investigate_read_descriptor(struct net_device *dev,struct xircom_private *card, int descnr, unsigned int bufferoffset);
static void investigate_write_descriptor(struct net_device *dev, struct xircom_private *card, int descnr, unsigned int bufferoffset);
static void read_mac_address(struct xircom_private *card);
static void transceiver_voodoo(struct xircom_private *card);
static void initialize_card(struct xircom_private *card);
static void trigger_transmit(struct xircom_private *card);
static void trigger_receive(struct xircom_private *card);
static void setup_descriptors(struct xircom_private *card);
static void remove_descriptors(struct xircom_private *card);
static int link_status_changed(struct xircom_private *card);
static void activate_receiver(struct xircom_private *card);
static void deactivate_receiver(struct xircom_private *card);
static void activate_transmitter(struct xircom_private *card);
static void deactivate_transmitter(struct xircom_private *card);
static void enable_transmit_interrupt(struct xircom_private *card);
static void enable_receive_interrupt(struct xircom_private *card);
static void enable_link_interrupt(struct xircom_private *card);
static void disable_all_interrupts(struct xircom_private *card);
static int link_status(struct xircom_private *card);



static struct pci_device_id xircom_pci_table[] = {
	{0x115D, 0x0003, PCI_ANY_ID, PCI_ANY_ID,},
	{0,},
};
MODULE_DEVICE_TABLE(pci, xircom_pci_table);

static struct pci_driver xircom_ops = {
	.name		= "xircom_cb",
	.id_table	= xircom_pci_table,
	.probe		= xircom_probe,
	.remove		= xircom_remove,
	.suspend =NULL,
	.resume =NULL
};


#ifdef DEBUG
static void print_binary(unsigned int number)
{
	int i,i2;
	char buffer[64];
	memset(buffer,0,64);
	i2=0;
	for (i=31;i>=0;i--) {
		if (number & (1<<i))
			buffer[i2++]='1';
		else
			buffer[i2++]='0';
		if ((i&3)==0)
			buffer[i2++]=' ';
	}
	printk("%s\n",buffer);
}
#endif

static void netdev_get_drvinfo(struct net_device *dev,
			       struct ethtool_drvinfo *info)
{
	struct xircom_private *private = netdev_priv(dev);

	strcpy(info->driver, "xircom_cb");
	strcpy(info->bus_info, pci_name(private->pdev));
}

static const struct ethtool_ops netdev_ethtool_ops = {
	.get_drvinfo		= netdev_get_drvinfo,
};

/* xircom_probe is the code that gets called on device insertion.
   it sets up the hardware and registers the device to the networklayer.

   TODO: Send 1 or 2 "dummy" packets here as the card seems to discard the
         first two packets that get send, and pump hates that.

 */
static int __devinit xircom_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
	struct net_device *dev = NULL;
	struct xircom_private *private;
	unsigned long flags;
	unsigned short tmp16;
	enter("xircom_probe");

	/* First do the PCI initialisation */

	if (pci_enable_device(pdev))
		return -ENODEV;

	/* disable all powermanagement */
	pci_write_config_dword(pdev, PCI_POWERMGMT, 0x0000);

	pci_set_master(pdev); /* Why isn't this done by pci_enable_device ?*/

	/* clear PCI status, if any */
	pci_read_config_word (pdev,PCI_STATUS, &tmp16);
	pci_write_config_word (pdev, PCI_STATUS,tmp16);

	if (!request_region(pci_resource_start(pdev, 0), 128, "xircom_cb")) {
		printk(KERN_ERR "xircom_probe: failed to allocate io-region\n");
		return -ENODEV;
	}

	/*
	   Before changing the hardware, allocate the memory.
	   This way, we can fail gracefully if not enough memory
	   is available.
	 */
	dev = alloc_etherdev(sizeof(struct xircom_private));
	if (!dev) {
		printk(KERN_ERR "xircom_probe: failed to allocate etherdev\n");
		goto device_fail;
	}
	private = netdev_priv(dev);

	/* Allocate the send/receive buffers */
	private->rx_buffer = pci_alloc_consistent(pdev,8192,&private->rx_dma_handle);
	if (private->rx_buffer == NULL) {
 		printk(KERN_ERR "xircom_probe: no memory for rx buffer \n");
		goto rx_buf_fail;
	}
	private->tx_buffer = pci_alloc_consistent(pdev,8192,&private->tx_dma_handle);
	if (private->tx_buffer == NULL) {
		printk(KERN_ERR "xircom_probe: no memory for tx buffer \n");
		goto tx_buf_fail;
	}

	SET_NETDEV_DEV(dev, &pdev->dev);


	private->dev = dev;
	private->pdev = pdev;
	private->io_port = pci_resource_start(pdev, 0);
	spin_lock_init(&private->lock);
	dev->irq = pdev->irq;
	dev->base_addr = private->io_port;

	initialize_card(private);
	read_mac_address(private);
	setup_descriptors(private);

	dev->open = &xircom_open;
	dev->hard_start_xmit = &xircom_start_xmit;
	dev->stop = &xircom_close;
	dev->get_stats = &xircom_get_stats;
#ifdef CONFIG_NET_POLL_CONTROLLER
	dev->poll_controller = &xircom_poll_controller;
#endif
	SET_ETHTOOL_OPS(dev, &netdev_ethtool_ops);
	pci_set_drvdata(pdev, dev);

	if (register_netdev(dev)) {
		printk(KERN_ERR "xircom_probe: netdevice registration failed.\n");
		goto reg_fail;
	}

	printk(KERN_INFO "%s: Xircom cardbus revision %i at irq %i \n", dev->name, pdev->revision, pdev->irq);
	/* start the transmitter to get a heartbeat */
	/* TODO: send 2 dummy packets here */
	transceiver_voodoo(private);

	spin_lock_irqsave(&private->lock,flags);
	activate_transmitter(private);
	activate_receiver(private);
	spin_unlock_irqrestore(&private->lock,flags);

	trigger_receive(private);

	leave("xircom_probe");
	return 0;

reg_fail:
	kfree(private->tx_buffer);
tx_buf_fail:
	kfree(private->rx_buffer);
rx_buf_fail:
	free_netdev(dev);
device_fail:
	return -ENODEV;
}


/*
 xircom_remove is called on module-unload or on device-eject.
 it unregisters the irq, io-region and network device.
 Interrupts and such are already stopped in the "ifconfig ethX down"
 code.
 */
static void __devexit xircom_remove(struct pci_dev *pdev)
{
	struct net_device *dev = pci_get_drvdata(pdev);
	struct xircom_private *card = netdev_priv(dev);

	enter("xircom_remove");
	pci_free_consistent(pdev,8192,card->rx_buffer,card->rx_dma_handle);
	pci_free_consistent(pdev,8192,card->tx_buffer,card->tx_dma_handle);

	release_region(dev->base_addr, 128);
	unregister_netdev(dev);
	free_netdev(dev);
	pci_set_drvdata(pdev, NULL);
	leave("xircom_remove");
}

static irqreturn_t xircom_interrupt(int irq, void *dev_instance)
{
	struct net_device *dev = (struct net_device *) dev_instance;
	struct xircom_private *card = netdev_priv(dev);
	unsigned int status;
	int i;

	enter("xircom_interrupt\n");

	spin_lock(&card->lock);
	status = inl(card->io_port+CSR5);

#ifdef DEBUG
	print_binary(status);
	printk("tx status 0x%08x 0x%08x \n",card->tx_buffer[0],card->tx_buffer[4]);
	printk("rx status 0x%08x 0x%08x \n",card->rx_buffer[0],card->rx_buffer[4]);
#endif
	/* Handle shared irq and hotplug */
	if (status == 0 || status == 0xffffffff) {
		spin_unlock(&card->lock);
		return IRQ_NONE;
	}

	if (link_status_changed(card)) {
		int newlink;
		printk(KERN_DEBUG "xircom_cb: Link status has changed \n");
		newlink = link_status(card);
		printk(KERN_INFO  "xircom_cb: Link is %i mbit \n",newlink);
		if (newlink)
			netif_carrier_on(dev);
		else
			netif_carrier_off(dev);

	}

	/* Clear all remaining interrupts */
	status |= 0xffffffff; /* FIXME: make this clear only the
				        real existing bits */
	outl(status,card->io_port+CSR5);


	for (i=0;i<NUMDESCRIPTORS;i++)
		investigate_write_descriptor(dev,card,i,bufferoffsets[i]);
	for (i=0;i<NUMDESCRIPTORS;i++)
		investigate_read_descriptor(dev,card,i,bufferoffsets[i]);


	spin_unlock(&card->lock);
	leave("xircom_interrupt");
	return IRQ_HANDLED;
}

static int xircom_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct xircom_private *card;
	unsigned long flags;
	int nextdescriptor;
	int desc;
	enter("xircom_start_xmit");

	card = netdev_priv(dev);
	spin_lock_irqsave(&card->lock,flags);

	/* First see if we can free some descriptors */
	for (desc=0;desc<NUMDESCRIPTORS;desc++)
		investigate_write_descriptor(dev,card,desc,bufferoffsets[desc]);


	nextdescriptor = (card->transmit_used +1) % (NUMDESCRIPTORS);
	desc = card->transmit_used;

	/* only send the packet if the descriptor is free */
	if (card->tx_buffer[4*desc]==0) {
			/* Copy the packet data; zero the memory first as the card
			   sometimes sends more than you ask it to. */

			memset(&card->tx_buffer[bufferoffsets[desc]/4],0,1536);
			skb_copy_from_linear_data(skb,
				  &(card->tx_buffer[bufferoffsets[desc] / 4]),
						  skb->len);
			/* FIXME: The specification tells us that the length we send HAS to be a multiple of
			   4 bytes. */

			card->tx_buffer[4*desc+1] = cpu_to_le32(skb->len);
			if (desc == NUMDESCRIPTORS - 1) /* bit 25: last descriptor of the ring */
				card->tx_buffer[4*desc+1] |= cpu_to_le32(1<<25);  

			card->tx_buffer[4*desc+1] |= cpu_to_le32(0xF0000000);
						 /* 0xF0... means want interrupts*/
			card->tx_skb[desc] = skb;

			wmb();
			/* This gives the descriptor to the card */
			card->tx_buffer[4*desc] = cpu_to_le32(0x80000000);
			trigger_transmit(card);
			if (card->tx_buffer[nextdescriptor*4] & cpu_to_le32(0x8000000)) {
				/* next descriptor is occupied... */
				netif_stop_queue(dev);
			}
			card->transmit_used = nextdescriptor;
			leave("xircom-start_xmit - sent");
			spin_unlock_irqrestore(&card->lock,flags);
			return 0;
	}



	/* Uh oh... no free descriptor... drop the packet */
	netif_stop_queue(dev);
	spin_unlock_irqrestore(&card->lock,flags);
	trigger_transmit(card);

	return NETDEV_TX_BUSY;
}




static int xircom_open(struct net_device *dev)
{
	struct xircom_private *xp = netdev_priv(dev);
	int retval;
	enter("xircom_open");
	printk(KERN_INFO "xircom cardbus adaptor found, registering as %s, using irq %i \n",dev->name,dev->irq);
	retval = request_irq(dev->irq, &xircom_interrupt, IRQF_SHARED, dev->name, dev);
	if (retval) {
		leave("xircom_open - No IRQ");
		return retval;
	}

	xircom_up(xp);
	xp->open = 1;
	leave("xircom_open");
	return 0;
}

static int xircom_close(struct net_device *dev)
{
	struct xircom_private *card;
	unsigned long flags;

	enter("xircom_close");
	card = netdev_priv(dev);
	netif_stop_queue(dev); /* we don't want new packets */


	spin_lock_irqsave(&card->lock,flags);

	disable_all_interrupts(card);
#if 0
	/* We can enable this again once we send dummy packets on ifconfig ethX up */
	deactivate_receiver(card);
	deactivate_transmitter(card);
#endif
	remove_descriptors(card);

	spin_unlock_irqrestore(&card->lock,flags);

	card->open = 0;
	free_irq(dev->irq,dev);

	leave("xircom_close");

	return 0;

}



static struct net_device_stats *xircom_get_stats(struct net_device *dev)
{
        struct xircom_private *card = netdev_priv(dev);
        return &card->stats;
}


#ifdef CONFIG_NET_POLL_CONTROLLER
static void xircom_poll_controller(struct net_device *dev)
{
	disable_irq(dev->irq);
	xircom_interrupt(dev->irq, dev);
	enable_irq(dev->irq);
}
#endif


static void initialize_card(struct xircom_private *card)
{
	unsigned int val;
	unsigned long flags;
	enter("initialize_card");


	spin_lock_irqsave(&card->lock, flags);

	/* First: reset the card */
	val = inl(card->io_port + CSR0);
	val |= 0x01;		/* Software reset */
	outl(val, card->io_port + CSR0);

	udelay(100);		/* give the card some time to reset */

	val = inl(card->io_port + CSR0);
	val &= ~0x01;		/* disable Software reset */
	outl(val, card->io_port + CSR0);


	val = 0;		/* Value 0x00 is a safe and conservative value
				   for the PCI configuration settings */
	outl(val, card->io_port + CSR0);


	disable_all_interrupts(card);
	deactivate_receiver(card);
	deactivate_transmitter(card);

	spin_unlock_irqrestore(&card->lock, flags);

	leave("initialize_card");
}

/*
trigger_transmit causes the card to check for frames to be transmitted.
This is accomplished by writing to the CSR1 port. The documentation
claims that the act of writing is sufficient and that the value is
ignored; I chose zero.
*/
static void trigger_transmit(struct xircom_private *card)
{
	unsigned int val;
	enter("trigger_transmit");

	val = 0;
	outl(val, card->io_port + CSR1);

	leave("trigger_transmit");
}

/*
trigger_receive causes the card to check for empty frames in the
descriptor list in which packets can be received.
This is accomplished by writing to the CSR2 port. The documentation
claims that the act of writing is sufficient and that the value is
ignored; I chose zero.
*/
static void trigger_receive(struct xircom_private *card)
{
	unsigned int val;
	enter("trigger_receive");

	val = 0;
	outl(val, card->io_port + CSR2);

	leave("trigger_receive");
}

/*
setup_descriptors initializes the send and receive buffers to be valid
descriptors and programs the addresses into the card.
*/
static void setup_descriptors(struct xircom_private *card)
{
	u32 address;
	int i;
	enter("setup_descriptors");


	BUG_ON(card->rx_buffer == NULL);
	BUG_ON(card->tx_buffer == NULL);

	/* Receive descriptors */
	memset(card->rx_buffer, 0, 128);	/* clear the descriptors */
	for (i=0;i<NUMDESCRIPTORS;i++ ) {

		/* Rx Descr0: It's empty, let the card own it, no errors -> 0x80000000 */
		card->rx_buffer[i*4 + 0] = cpu_to_le32(0x80000000);
		/* Rx Descr1: buffer 1 is 1536 bytes, buffer 2 is 0 bytes */
		card->rx_buffer[i*4 + 1] = cpu_to_le32(1536);
		if (i == NUMDESCRIPTORS - 1) /* bit 25 is "last descriptor" */
			card->rx_buffer[i*4 + 1] |= cpu_to_le32(1 << 25);

		/* Rx Descr2: address of the buffer
		   we store the buffer at the 2nd half of the page */

		address = card->rx_dma_handle;
		card->rx_buffer[i*4 + 2] = cpu_to_le32(address + bufferoffsets[i]);
		/* Rx Desc3: address of 2nd buffer -> 0 */
		card->rx_buffer[i*4 + 3] = 0;
	}

	wmb();
	/* Write the receive descriptor ring address to the card */
	address = card->rx_dma_handle;
	outl(address, card->io_port + CSR3);	/* Receive descr list address */


	/* transmit descriptors */
	memset(card->tx_buffer, 0, 128);	/* clear the descriptors */

	for (i=0;i<NUMDESCRIPTORS;i++ ) {
		/* Tx Descr0: Empty, we own it, no errors -> 0x00000000 */
		card->tx_buffer[i*4 + 0] = 0x00000000;
		/* Tx Descr1: buffer 1 is 1536 bytes, buffer 2 is 0 bytes */
		card->tx_buffer[i*4 + 1] = cpu_to_le32(1536);
		if (i == NUMDESCRIPTORS - 1) /* bit 25 is "last descriptor" */
			card->tx_buffer[i*4 + 1] |= cpu_to_le32(1 << 25);

		/* Tx Descr2: address of the buffer
		   we store the buffer at the 2nd half of the page */
		address = card->tx_dma_handle;
		card->tx_buffer[i*4 + 2] = cpu_to_le32(address + bufferoffsets[i]);
		/* Tx Desc3: address of 2nd buffer -> 0 */
		card->tx_buffer[i*4 + 3] = 0;
	}

	wmb();
	/* wite the transmit descriptor ring to the card */
	address = card->tx_dma_handle;
	outl(address, card->io_port + CSR4);	/* xmit descr list address */

	leave("setup_descriptors");
}

/*
remove_descriptors informs the card the descriptors are no longer
valid by setting the address in the card to 0x00.
*/
static void remove_descriptors(struct xircom_private *card)
{
	unsigned int val;
	enter("remove_descriptors");

	val = 0;
	outl(val, card->io_port + CSR3);	/* Receive descriptor address */
	outl(val, card->io_port + CSR4);	/* Send descriptor address */

	leave("remove_descriptors");
}

/*
link_status_changed returns 1 if the card has indicated that
the link status has changed. The new link status has to be read from CSR12.

This function also clears the status-bit.
*/
static int link_status_changed(struct xircom_private *card)
{
	unsigned int val;
	enter("link_status_changed");

	val = inl(card->io_port + CSR5);	/* Status register */

	if ((val & (1 << 27)) == 0) {	/* no change */
		leave("link_status_changed - nochange");
		return 0;
	}

	/* clear the event by writing a 1 to the bit in the
	   status register. */
	val = (1 << 27);
	outl(val, card->io_port + CSR5);

	leave("link_status_changed - changed");
	return 1;
}


/*
transmit_active returns 1 if the transmitter on the card is
in a non-stopped state.
*/
static int transmit_active(struct xircom_private *card)
{
	unsigned int val;
	enter("transmit_active");

	val = inl(card->io_port + CSR5);	/* Status register */

	if ((val & (7 << 20)) == 0) {	/* transmitter disabled */
		leave("transmit_active - inactive");
		return 0;
	}

	leave("transmit_active - active");
	return 1;
}

/*
receive_active returns 1 if the receiver on the card is
in a non-stopped state.
*/
static int receive_active(struct xircom_private *card)
{
	unsigned int val;
	enter("receive_active");


	val = inl(card->io_port + CSR5);	/* Status register */

	if ((val & (7 << 17)) == 0) {	/* receiver disabled */
		leave("receive_active - inactive");
		return 0;
	}

	leave("receive_active - active");
	return 1;
}

/*
activate_receiver enables the receiver on the card.
Before being allowed to active the receiver, the receiver
must be completely de-activated. To achieve this,
this code actually disables the receiver first; then it waits for the
receiver to become inactive, then it activates the receiver and then
it waits for the receiver to be active.

must be called with the lock held and interrupts disabled.
*/
static void activate_receiver(struct xircom_private *card)
{
	unsigned int val;
	int counter;
	enter("activate_receiver");


	val = inl(card->io_port + CSR6);	/* Operation mode */

	/* If the "active" bit is set and the receiver is already
	   active, no need to do the expensive thing */
	if ((val&2) && (receive_active(card)))
		return;


	val = val & ~2;		/* disable the receiver */
	outl(val, card->io_port + CSR6);

	counter = 10;
	while (counter > 0) {
		if (!receive_active(card))
			break;
		/* wait a while */
		udelay(50);
		counter--;
		if (counter <= 0)
			printk(KERN_ERR "xircom_cb: Receiver failed to deactivate\n");
	}

	/* enable the receiver */
	val = inl(card->io_port + CSR6);	/* Operation mode */
	val = val | 2;				/* enable the receiver */
	outl(val, card->io_port + CSR6);

	/* now wait for the card to activate again */
	counter = 10;
	while (counter > 0) {
		if (receive_active(card))
			break;
		/* wait a while */
		udelay(50);
		counter--;
		if (counter <= 0)
			printk(KERN_ERR "xircom_cb: Receiver failed to re-activate\n");
	}

	leave("activate_receiver");
}

/*
deactivate_receiver disables the receiver on the card.
To achieve this this code disables the receiver first;
then it waits for the receiver to become inactive.

must be called with the lock held and interrupts disabled.
*/
static void deactivate_receiver(struct xircom_private *card)
{
	unsigned int val;
	int counter;
	enter("deactivate_receiver");

	val = inl(card->io_port + CSR6);	/* Operation mode */
	val = val & ~2;				/* disable the receiver */
	outl(val, card->io_port + CSR6);

	counter = 10;
	while (counter > 0) {
		if (!receive_active(card))
			break;
		/* wait a while */
		udelay(50);
		counter--;
		if (counter <= 0)
			printk(KERN_ERR "xircom_cb: Receiver failed to deactivate\n");
	}


	leave("deactivate_receiver");
}


/*
activate_transmitter enables the transmitter on the card.
Before being allowed to active the transmitter, the transmitter
must be completely de-activated. To achieve this,
this code actually disables the transmitter first; then it waits for the
transmitter to become inactive, then it activates the transmitter and then
it waits for the transmitter to be active again.

must be called with the lock held and interrupts disabled.
*/
static void activate_transmitter(struct xircom_private *card)
{
	unsigned int val;
	int counter;
	enter("activate_transmitter");


	val = inl(card->io_port + CSR6);	/* Operation mode */

	/* If the "active" bit is set and the receiver is already
	   active, no need to do the expensive thing */
	if ((val&(1<<13)) && (transmit_active(card)))
		return;

	val = val & ~(1 << 13);	/* disable the transmitter */
	outl(val, card->io_port + CSR6);

	counter = 10;
	while (counter > 0) {
		if (!transmit_active(card))
			break;
		/* wait a while */
		udelay(50);
		counter--;
		if (counter <= 0)
			printk(KERN_ERR "xircom_cb: Transmitter failed to deactivate\n");
	}

	/* enable the transmitter */
	val = inl(card->io_port + CSR6);	/* Operation mode */
	val = val | (1 << 13);	/* enable the transmitter */
	outl(val, card->io_port + CSR6);

	/* now wait for the card to activate again */
	counter = 10;
	while (counter > 0) {
		if (transmit_active(card))
			break;
		/* wait a while */
		udelay(50);
		counter--;
		if (counter <= 0)
			printk(KERN_ERR "xircom_cb: Transmitter failed to re-activate\n");
	}

	leave("activate_transmitter");
}

/*
deactivate_transmitter disables the transmitter on the card.
To achieve this this code disables the transmitter first;
then it waits for the transmitter to become inactive.

must be called with the lock held and interrupts disabled.
*/
static void deactivate_transmitter(struct xircom_private *card)
{
	unsigned int val;
	int counter;
	enter("deactivate_transmitter");

	val = inl(card->io_port + CSR6);	/* Operation mode */
	val = val & ~2;		/* disable the transmitter */
	outl(val, card->io_port + CSR6);

	counter = 20;
	while (counter > 0) {
		if (!transmit_active(card))
			break;
		/* wait a while */
		udelay(50);
		counter--;
		if (counter <= 0)
			printk(KERN_ERR "xircom_cb: Transmitter failed to deactivate\n");
	}


	leave("deactivate_transmitter");
}


/*
enable_transmit_interrupt enables the transmit interrupt

must be called with the lock held and interrupts disabled.
*/
static void enable_transmit_interrupt(struct xircom_private *card)
{
	unsigned int val;
	enter("enable_transmit_interrupt");

	val = inl(card->io_port + CSR7);	/* Interrupt enable register */
	val |= 1;				/* enable the transmit interrupt */
	outl(val, card->io_port + CSR7);

	leave("enable_transmit_interrupt");
}


/*
enable_receive_interrupt enables the receive interrupt

must be called with the lock held and interrupts disabled.
*/
static void enable_receive_interrupt(struct xircom_private *card)
{
	unsigned int val;
	enter("enable_receive_interrupt");

	val = inl(card->io_port + CSR7);	/* Interrupt enable register */
	val = val | (1 << 6);			/* enable the receive interrupt */
	outl(val, card->io_port + CSR7);

	leave("enable_receive_interrupt");
}

/*
enable_link_interrupt enables the link status change interrupt

must be called with the lock held and interrupts disabled.
*/
static void enable_link_interrupt(struct xircom_private *card)
{
	unsigned int val;
	enter("enable_link_interrupt");

	val = inl(card->io_port + CSR7);	/* Interrupt enable register */
	val = val | (1 << 27);			/* enable the link status chage interrupt */
	outl(val, card->io_port + CSR7);

	leave("enable_link_interrupt");
}



/*
disable_all_interrupts disables all interrupts

must be called with the lock held and interrupts disabled.
*/
static void disable_all_interrupts(struct xircom_private *card)
{
	unsigned int val;
	enter("enable_all_interrupts");

	val = 0;				/* disable all interrupts */
	outl(val, card->io_port + CSR7);

	leave("disable_all_interrupts");
}

/*
enable_common_interrupts enables several weird interrupts

must be called with the lock held and interrupts disabled.
*/
static void enable_common_interrupts(struct xircom_private *card)
{
	unsigned int val;
	enter("enable_link_interrupt");

	val = inl(card->io_port + CSR7);	/* Interrupt enable register */
	val |= (1<<16); /* Normal Interrupt Summary */
	val |= (1<<15); /* Abnormal Interrupt Summary */
	val |= (1<<13); /* Fatal bus error */
	val |= (1<<8);  /* Receive Process Stopped */
	val |= (1<<7);  /* Receive Buffer Unavailable */
	val |= (1<<5);  /* Transmit Underflow */
	val |= (1<<2);  /* Transmit Buffer Unavailable */
	val |= (1<<1);  /* Transmit Process Stopped */
	outl(val, card->io_port + CSR7);

	leave("enable_link_interrupt");
}

/*
enable_promisc starts promisc mode

must be called with the lock held and interrupts disabled.
*/
static int enable_promisc(struct xircom_private *card)
{
	unsigned int val;
	enter("enable_promisc");

	val = inl(card->io_port + CSR6);
	val = val | (1 << 6);
	outl(val, card->io_port + CSR6);

	leave("enable_promisc");
	return 1;
}




/*
link_status() checks the links status and will return 0 for no link, 10 for 10mbit link and 100 for.. guess what.

Must be called in locked state with interrupts disabled
*/
static int link_status(struct xircom_private *card)
{
	unsigned int val;
	enter("link_status");

	val = inb(card->io_port + CSR12);

	if (!(val&(1<<2)))  /* bit 2 is 0 for 10mbit link, 1 for not an 10mbit link */
		return 10;
	if (!(val&(1<<1)))  /* bit 1 is 0 for 100mbit link, 1 for not an 100mbit link */
		return 100;

	/* If we get here -> no link at all */

	leave("link_status");
	return 0;
}





/*
  read_mac_address() reads the MAC address from the NIC and stores it in the "dev" structure.

  This function will take the spinlock itself and can, as a result, not be called with the lock helt.
 */
static void read_mac_address(struct xircom_private *card)
{
	unsigned char j, tuple, link, data_id, data_count;
	unsigned long flags;
	int i;

	enter("read_mac_address");

	spin_lock_irqsave(&card->lock, flags);

	outl(1 << 12, card->io_port + CSR9);	/* enable boot rom access */
	for (i = 0x100; i < 0x1f7; i += link + 2) {
		outl(i, card->io_port + CSR10);
		tuple = inl(card->io_port + CSR9) & 0xff;
		outl(i + 1, card->io_port + CSR10);
		link = inl(card->io_port + CSR9) & 0xff;
		outl(i + 2, card->io_port + CSR10);
		data_id = inl(card->io_port + CSR9) & 0xff;
		outl(i + 3, card->io_port + CSR10);
		data_count = inl(card->io_port + CSR9) & 0xff;
		if ((tuple == 0x22) && (data_id == 0x04) && (data_count == 0x06)) {
			/*
			 * This is it.  We have the data we want.
			 */
			for (j = 0; j < 6; j++) {
				outl(i + j + 4, card->io_port + CSR10);
				card->dev->dev_addr[j] = inl(card->io_port + CSR9) & 0xff;
			}
			break;
		} else if (link == 0) {
			break;
		}
	}
	spin_unlock_irqrestore(&card->lock, flags);
	pr_debug(" %pM\n", card->dev->dev_addr);
	leave("read_mac_address");
}


/*
 transceiver_voodoo() enables the external UTP plug thingy.
 it's called voodoo as I stole this code and cannot cross-reference
 it with the specification.
 */
static void transceiver_voodoo(struct xircom_private *card)
{
	unsigned long flags;

	enter("transceiver_voodoo");

	/* disable all powermanagement */
	pci_write_config_dword(card->pdev, PCI_POWERMGMT, 0x0000);

	setup_descriptors(card);

	spin_lock_irqsave(&card->lock, flags);

	outl(0x0008, card->io_port + CSR15);
        udelay(25);
        outl(0xa8050000, card->io_port + CSR15);
        udelay(25);
        outl(0xa00f0000, card->io_port + CSR15);
        udelay(25);

        spin_unlock_irqrestore(&card->lock, flags);

	netif_start_queue(card->dev);
	leave("transceiver_voodoo");
}


static void xircom_up(struct xircom_private *card)
{
	unsigned long flags;
	int i;

	enter("xircom_up");

	/* disable all powermanagement */
	pci_write_config_dword(card->pdev, PCI_POWERMGMT, 0x0000);

	setup_descriptors(card);

	spin_lock_irqsave(&card->lock, flags);


	enable_link_interrupt(card);
	enable_transmit_interrupt(card);
	enable_receive_interrupt(card);
	enable_common_interrupts(card);
	enable_promisc(card);

	/* The card can have received packets already, read them away now */
	for (i=0;i<NUMDESCRIPTORS;i++)
		investigate_read_descriptor(card->dev,card,i,bufferoffsets[i]);


	spin_unlock_irqrestore(&card->lock, flags);
	trigger_receive(card);
	trigger_transmit(card);
	netif_start_queue(card->dev);
	leave("xircom_up");
}

/* Bufferoffset is in BYTES */
static void investigate_read_descriptor(struct net_device *dev,struct xircom_private *card, int descnr, unsigned int bufferoffset)
{
		int status;

		enter("investigate_read_descriptor");
		status = le32_to_cpu(card->rx_buffer[4*descnr]);

		if ((status > 0)) {	/* packet received */

			/* TODO: discard error packets */

			short pkt_len = ((status >> 16) & 0x7ff) - 4;	/* minus 4, we don't want the CRC */
			struct sk_buff *skb;

			if (pkt_len > 1518) {
				printk(KERN_ERR "xircom_cb: Packet length %i is bogus \n",pkt_len);
				pkt_len = 1518;
			}

			skb = dev_alloc_skb(pkt_len + 2);
			if (skb == NULL) {
				card->stats.rx_dropped++;
				goto out;
			}
			skb_reserve(skb, 2);
			skb_copy_to_linear_data(skb, (unsigned char*)&card->rx_buffer[bufferoffset / 4], pkt_len);
			skb_put(skb, pkt_len);
			skb->protocol = eth_type_trans(skb, dev);
			netif_rx(skb);
			card->stats.rx_packets++;
			card->stats.rx_bytes += pkt_len;

		      out:
			/* give the buffer back to the card */
			card->rx_buffer[4*descnr] =  cpu_to_le32(0x80000000);
			trigger_receive(card);
		}

		leave("investigate_read_descriptor");

}


/* Bufferoffset is in BYTES */
static void investigate_write_descriptor(struct net_device *dev, struct xircom_private *card, int descnr, unsigned int bufferoffset)
{
		int status;

		enter("investigate_write_descriptor");

		status = le32_to_cpu(card->tx_buffer[4*descnr]);
#if 0
		if (status & 0x8000) {	/* Major error */
			printk(KERN_ERR "Major transmit error status %x \n", status);
			card->tx_buffer[4*descnr] = 0;
			netif_wake_queue (dev);
		}
#endif
		if (status > 0) {	/* bit 31 is 0 when done */
			if (card->tx_skb[descnr]!=NULL) {
				card->stats.tx_bytes += card->tx_skb[descnr]->len;
				dev_kfree_skb_irq(card->tx_skb[descnr]);
			}
			card->tx_skb[descnr] = NULL;
			/* Bit 8 in the status field is 1 if there was a collision */
			if (status&(1<<8))
				card->stats.collisions++;
			card->tx_buffer[4*descnr] = 0; /* descriptor is free again */
			netif_wake_queue (dev);
			card->stats.tx_packets++;
		}

		leave("investigate_write_descriptor");

}


static int __init xircom_init(void)
{
	return pci_register_driver(&xircom_ops);
}

static void __exit xircom_exit(void)
{
	pci_unregister_driver(&xircom_ops);
}

module_init(xircom_init)
module_exit(xircom_exit)