aboutsummaryrefslogtreecommitdiff
path: root/drivers/net/usb/smsc95xx.c
blob: 09bd6351f64c1fb7020c764ff11253b04822598c (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
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
1265
1266
1267
1268
1269
1270
1271
1272
 /***************************************************************************
 *
 * Copyright (C) 2007-2008 SMSC
 *
 * 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
 * of the License, 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 *****************************************************************************/

#include <linux/module.h>
#include <linux/kmod.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/mii.h>
#include <linux/usb.h>
#include <linux/crc32.h>
#include <linux/usb/usbnet.h>
#include "smsc95xx.h"

#define SMSC_CHIPNAME			"smsc95xx"
#define SMSC_DRIVER_VERSION		"1.0.4"
#define HS_USB_PKT_SIZE			(512)
#define FS_USB_PKT_SIZE			(64)
#define DEFAULT_HS_BURST_CAP_SIZE	(16 * 1024 + 5 * HS_USB_PKT_SIZE)
#define DEFAULT_FS_BURST_CAP_SIZE	(6 * 1024 + 33 * FS_USB_PKT_SIZE)
#define DEFAULT_BULK_IN_DELAY		(0x00002000)
#define MAX_SINGLE_PACKET_SIZE		(2048)
#define LAN95XX_EEPROM_MAGIC		(0x9500)
#define EEPROM_MAC_OFFSET		(0x01)
#define DEFAULT_TX_CSUM_ENABLE		(true)
#define DEFAULT_RX_CSUM_ENABLE		(true)
#define SMSC95XX_INTERNAL_PHY_ID	(1)
#define SMSC95XX_TX_OVERHEAD		(8)
#define SMSC95XX_TX_OVERHEAD_CSUM	(12)

struct smsc95xx_priv {
	u32 mac_cr;
	spinlock_t mac_cr_lock;
	bool use_tx_csum;
	bool use_rx_csum;
};

struct usb_context {
	struct usb_ctrlrequest req;
	struct usbnet *dev;
};

static int turbo_mode = true;
module_param(turbo_mode, bool, 0644);
MODULE_PARM_DESC(turbo_mode, "Enable multiple frames per Rx transaction");

static int smsc95xx_read_reg(struct usbnet *dev, u32 index, u32 *data)
{
	u32 *buf = kmalloc(4, GFP_KERNEL);
	int ret;

	BUG_ON(!dev);

	if (!buf)
		return -ENOMEM;

	ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
		USB_VENDOR_REQUEST_READ_REGISTER,
		USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
		00, index, buf, 4, USB_CTRL_GET_TIMEOUT);

	if (unlikely(ret < 0))
		devwarn(dev, "Failed to read register index 0x%08x", index);

	le32_to_cpus(buf);
	*data = *buf;
	kfree(buf);

	return ret;
}

static int smsc95xx_write_reg(struct usbnet *dev, u32 index, u32 data)
{
	u32 *buf = kmalloc(4, GFP_KERNEL);
	int ret;

	BUG_ON(!dev);

	if (!buf)
		return -ENOMEM;

	*buf = data;
	cpu_to_le32s(buf);

	ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
		USB_VENDOR_REQUEST_WRITE_REGISTER,
		USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
		00, index, buf, 4, USB_CTRL_SET_TIMEOUT);

	if (unlikely(ret < 0))
		devwarn(dev, "Failed to write register index 0x%08x", index);

	kfree(buf);

	return ret;
}

/* Loop until the read is completed with timeout
 * called with phy_mutex held */
static int smsc95xx_phy_wait_not_busy(struct usbnet *dev)
{
	unsigned long start_time = jiffies;
	u32 val;

	do {
		smsc95xx_read_reg(dev, MII_ADDR, &val);
		if (!(val & MII_BUSY_))
			return 0;
	} while (!time_after(jiffies, start_time + HZ));

	return -EIO;
}

static int smsc95xx_mdio_read(struct net_device *netdev, int phy_id, int idx)
{
	struct usbnet *dev = netdev_priv(netdev);
	u32 val, addr;

	mutex_lock(&dev->phy_mutex);

	/* confirm MII not busy */
	if (smsc95xx_phy_wait_not_busy(dev)) {
		devwarn(dev, "MII is busy in smsc95xx_mdio_read");
		mutex_unlock(&dev->phy_mutex);
		return -EIO;
	}

	/* set the address, index & direction (read from PHY) */
	phy_id &= dev->mii.phy_id_mask;
	idx &= dev->mii.reg_num_mask;
	addr = (phy_id << 11) | (idx << 6) | MII_READ_;
	smsc95xx_write_reg(dev, MII_ADDR, addr);

	if (smsc95xx_phy_wait_not_busy(dev)) {
		devwarn(dev, "Timed out reading MII reg %02X", idx);
		mutex_unlock(&dev->phy_mutex);
		return -EIO;
	}

	smsc95xx_read_reg(dev, MII_DATA, &val);

	mutex_unlock(&dev->phy_mutex);

	return (u16)(val & 0xFFFF);
}

static void smsc95xx_mdio_write(struct net_device *netdev, int phy_id, int idx,
				int regval)
{
	struct usbnet *dev = netdev_priv(netdev);
	u32 val, addr;

	mutex_lock(&dev->phy_mutex);

	/* confirm MII not busy */
	if (smsc95xx_phy_wait_not_busy(dev)) {
		devwarn(dev, "MII is busy in smsc95xx_mdio_write");
		mutex_unlock(&dev->phy_mutex);
		return;
	}

	val = regval;
	smsc95xx_write_reg(dev, MII_DATA, val);

	/* set the address, index & direction (write to PHY) */
	phy_id &= dev->mii.phy_id_mask;
	idx &= dev->mii.reg_num_mask;
	addr = (phy_id << 11) | (idx << 6) | MII_WRITE_;
	smsc95xx_write_reg(dev, MII_ADDR, addr);

	if (smsc95xx_phy_wait_not_busy(dev))
		devwarn(dev, "Timed out writing MII reg %02X", idx);

	mutex_unlock(&dev->phy_mutex);
}

static int smsc95xx_wait_eeprom(struct usbnet *dev)
{
	unsigned long start_time = jiffies;
	u32 val;

	do {
		smsc95xx_read_reg(dev, E2P_CMD, &val);
		if (!(val & E2P_CMD_BUSY_) || (val & E2P_CMD_TIMEOUT_))
			break;
		udelay(40);
	} while (!time_after(jiffies, start_time + HZ));

	if (val & (E2P_CMD_TIMEOUT_ | E2P_CMD_BUSY_)) {
		devwarn(dev, "EEPROM read operation timeout");
		return -EIO;
	}

	return 0;
}

static int smsc95xx_eeprom_confirm_not_busy(struct usbnet *dev)
{
	unsigned long start_time = jiffies;
	u32 val;

	do {
		smsc95xx_read_reg(dev, E2P_CMD, &val);

		if (!(val & E2P_CMD_BUSY_))
			return 0;

		udelay(40);
	} while (!time_after(jiffies, start_time + HZ));

	devwarn(dev, "EEPROM is busy");
	return -EIO;
}

static int smsc95xx_read_eeprom(struct usbnet *dev, u32 offset, u32 length,
				u8 *data)
{
	u32 val;
	int i, ret;

	BUG_ON(!dev);
	BUG_ON(!data);

	ret = smsc95xx_eeprom_confirm_not_busy(dev);
	if (ret)
		return ret;

	for (i = 0; i < length; i++) {
		val = E2P_CMD_BUSY_ | E2P_CMD_READ_ | (offset & E2P_CMD_ADDR_);
		smsc95xx_write_reg(dev, E2P_CMD, val);

		ret = smsc95xx_wait_eeprom(dev);
		if (ret < 0)
			return ret;

		smsc95xx_read_reg(dev, E2P_DATA, &val);

		data[i] = val & 0xFF;
		offset++;
	}

	return 0;
}

static int smsc95xx_write_eeprom(struct usbnet *dev, u32 offset, u32 length,
				 u8 *data)
{
	u32 val;
	int i, ret;

	BUG_ON(!dev);
	BUG_ON(!data);

	ret = smsc95xx_eeprom_confirm_not_busy(dev);
	if (ret)
		return ret;

	/* Issue write/erase enable command */
	val = E2P_CMD_BUSY_ | E2P_CMD_EWEN_;
	smsc95xx_write_reg(dev, E2P_CMD, val);

	ret = smsc95xx_wait_eeprom(dev);
	if (ret < 0)
		return ret;

	for (i = 0; i < length; i++) {

		/* Fill data register */
		val = data[i];
		smsc95xx_write_reg(dev, E2P_DATA, val);

		/* Send "write" command */
		val = E2P_CMD_BUSY_ | E2P_CMD_WRITE_ | (offset & E2P_CMD_ADDR_);
		smsc95xx_write_reg(dev, E2P_CMD, val);

		ret = smsc95xx_wait_eeprom(dev);
		if (ret < 0)
			return ret;

		offset++;
	}

	return 0;
}

static void smsc95xx_async_cmd_callback(struct urb *urb)
{
	struct usb_context *usb_context = urb->context;
	struct usbnet *dev = usb_context->dev;
	int status = urb->status;

	if (status < 0)
		devwarn(dev, "async callback failed with %d", status);

	kfree(usb_context);
	usb_free_urb(urb);
}

static int smsc95xx_write_reg_async(struct usbnet *dev, u16 index, u32 *data)
{
	struct usb_context *usb_context;
	int status;
	struct urb *urb;
	const u16 size = 4;

	urb = usb_alloc_urb(0, GFP_ATOMIC);
	if (!urb) {
		devwarn(dev, "Error allocating URB");
		return -ENOMEM;
	}

	usb_context = kmalloc(sizeof(struct usb_context), GFP_ATOMIC);
	if (usb_context == NULL) {
		devwarn(dev, "Error allocating control msg");
		usb_free_urb(urb);
		return -ENOMEM;
	}

	usb_context->req.bRequestType =
		USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE;
	usb_context->req.bRequest = USB_VENDOR_REQUEST_WRITE_REGISTER;
	usb_context->req.wValue = 00;
	usb_context->req.wIndex = cpu_to_le16(index);
	usb_context->req.wLength = cpu_to_le16(size);

	usb_fill_control_urb(urb, dev->udev, usb_sndctrlpipe(dev->udev, 0),
		(void *)&usb_context->req, data, size,
		smsc95xx_async_cmd_callback,
		(void *)usb_context);

	status = usb_submit_urb(urb, GFP_ATOMIC);
	if (status < 0) {
		devwarn(dev, "Error submitting control msg, sts=%d", status);
		kfree(usb_context);
		usb_free_urb(urb);
	}

	return status;
}

/* returns hash bit number for given MAC address
 * example:
 * 01 00 5E 00 00 01 -> returns bit number 31 */
static unsigned int smsc95xx_hash(char addr[ETH_ALEN])
{
	return (ether_crc(ETH_ALEN, addr) >> 26) & 0x3f;
}

static void smsc95xx_set_multicast(struct net_device *netdev)
{
	struct usbnet *dev = netdev_priv(netdev);
	struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
	u32 hash_hi = 0;
	u32 hash_lo = 0;
	unsigned long flags;

	spin_lock_irqsave(&pdata->mac_cr_lock, flags);

	if (dev->net->flags & IFF_PROMISC) {
		if (netif_msg_drv(dev))
			devdbg(dev, "promiscuous mode enabled");
		pdata->mac_cr |= MAC_CR_PRMS_;
		pdata->mac_cr &= ~(MAC_CR_MCPAS_ | MAC_CR_HPFILT_);
	} else if (dev->net->flags & IFF_ALLMULTI) {
		if (netif_msg_drv(dev))
			devdbg(dev, "receive all multicast enabled");
		pdata->mac_cr |= MAC_CR_MCPAS_;
		pdata->mac_cr &= ~(MAC_CR_PRMS_ | MAC_CR_HPFILT_);
	} else if (dev->net->mc_count > 0) {
		struct dev_mc_list *mc_list = dev->net->mc_list;
		int count = 0;

		pdata->mac_cr |= MAC_CR_HPFILT_;
		pdata->mac_cr &= ~(MAC_CR_PRMS_ | MAC_CR_MCPAS_);

		while (mc_list) {
			count++;
			if (mc_list->dmi_addrlen == ETH_ALEN) {
				u32 bitnum = smsc95xx_hash(mc_list->dmi_addr);
				u32 mask = 0x01 << (bitnum & 0x1F);
				if (bitnum & 0x20)
					hash_hi |= mask;
				else
					hash_lo |= mask;
			} else {
				devwarn(dev, "dmi_addrlen != 6");
			}
			mc_list = mc_list->next;
		}

		if (count != ((u32)dev->net->mc_count))
			devwarn(dev, "mc_count != dev->mc_count");

		if (netif_msg_drv(dev))
			devdbg(dev, "HASHH=0x%08X, HASHL=0x%08X", hash_hi,
				hash_lo);
	} else {
		if (netif_msg_drv(dev))
			devdbg(dev, "receive own packets only");
		pdata->mac_cr &=
			~(MAC_CR_PRMS_ | MAC_CR_MCPAS_ | MAC_CR_HPFILT_);
	}

	spin_unlock_irqrestore(&pdata->mac_cr_lock, flags);

	/* Initiate async writes, as we can't wait for completion here */
	smsc95xx_write_reg_async(dev, HASHH, &hash_hi);
	smsc95xx_write_reg_async(dev, HASHL, &hash_lo);
	smsc95xx_write_reg_async(dev, MAC_CR, &pdata->mac_cr);
}

static void smsc95xx_phy_update_flowcontrol(struct usbnet *dev, u8 duplex,
					    u16 lcladv, u16 rmtadv)
{
	u32 flow, afc_cfg = 0;

	int ret = smsc95xx_read_reg(dev, AFC_CFG, &afc_cfg);
	if (ret < 0) {
		devwarn(dev, "error reading AFC_CFG");
		return;
	}

	if (duplex == DUPLEX_FULL) {
		u8 cap = mii_resolve_flowctrl_fdx(lcladv, rmtadv);

		if (cap & FLOW_CTRL_RX)
			flow = 0xFFFF0002;
		else
			flow = 0;

		if (cap & FLOW_CTRL_TX)
			afc_cfg |= 0xF;
		else
			afc_cfg &= ~0xF;

		if (netif_msg_link(dev))
			devdbg(dev, "rx pause %s, tx pause %s",
				(cap & FLOW_CTRL_RX ? "enabled" : "disabled"),
				(cap & FLOW_CTRL_TX ? "enabled" : "disabled"));
	} else {
		if (netif_msg_link(dev))
			devdbg(dev, "half duplex");
		flow = 0;
		afc_cfg |= 0xF;
	}

	smsc95xx_write_reg(dev, FLOW, flow);
	smsc95xx_write_reg(dev,	AFC_CFG, afc_cfg);
}

static int smsc95xx_link_reset(struct usbnet *dev)
{
	struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
	struct mii_if_info *mii = &dev->mii;
	struct ethtool_cmd ecmd;
	unsigned long flags;
	u16 lcladv, rmtadv;
	u32 intdata;

	/* clear interrupt status */
	smsc95xx_mdio_read(dev->net, mii->phy_id, PHY_INT_SRC);
	intdata = 0xFFFFFFFF;
	smsc95xx_write_reg(dev, INT_STS, intdata);

	mii_check_media(mii, 1, 1);
	mii_ethtool_gset(&dev->mii, &ecmd);
	lcladv = smsc95xx_mdio_read(dev->net, mii->phy_id, MII_ADVERTISE);
	rmtadv = smsc95xx_mdio_read(dev->net, mii->phy_id, MII_LPA);

	if (netif_msg_link(dev))
		devdbg(dev, "speed: %d duplex: %d lcladv: %04x rmtadv: %04x",
			ecmd.speed, ecmd.duplex, lcladv, rmtadv);

	spin_lock_irqsave(&pdata->mac_cr_lock, flags);
	if (ecmd.duplex != DUPLEX_FULL) {
		pdata->mac_cr &= ~MAC_CR_FDPX_;
		pdata->mac_cr |= MAC_CR_RCVOWN_;
	} else {
		pdata->mac_cr &= ~MAC_CR_RCVOWN_;
		pdata->mac_cr |= MAC_CR_FDPX_;
	}
	spin_unlock_irqrestore(&pdata->mac_cr_lock, flags);

	smsc95xx_write_reg(dev, MAC_CR, pdata->mac_cr);

	smsc95xx_phy_update_flowcontrol(dev, ecmd.duplex, lcladv, rmtadv);

	return 0;
}

static void smsc95xx_status(struct usbnet *dev, struct urb *urb)
{
	u32 intdata;

	if (urb->actual_length != 4) {
		devwarn(dev, "unexpected urb length %d", urb->actual_length);
		return;
	}

	memcpy(&intdata, urb->transfer_buffer, 4);
	le32_to_cpus(&intdata);

	if (netif_msg_link(dev))
		devdbg(dev, "intdata: 0x%08X", intdata);

	if (intdata & INT_ENP_PHY_INT_)
		usbnet_defer_kevent(dev, EVENT_LINK_RESET);
	else
		devwarn(dev, "unexpected interrupt, intdata=0x%08X", intdata);
}

/* Enable or disable Tx & Rx checksum offload engines */
static int smsc95xx_set_csums(struct usbnet *dev)
{
	struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
	u32 read_buf;
	int ret = smsc95xx_read_reg(dev, COE_CR, &read_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to read COE_CR: %d", ret);
		return ret;
	}

	if (pdata->use_tx_csum)
		read_buf |= Tx_COE_EN_;
	else
		read_buf &= ~Tx_COE_EN_;

	if (pdata->use_rx_csum)
		read_buf |= Rx_COE_EN_;
	else
		read_buf &= ~Rx_COE_EN_;

	ret = smsc95xx_write_reg(dev, COE_CR, read_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to write COE_CR: %d", ret);
		return ret;
	}

	if (netif_msg_hw(dev))
		devdbg(dev, "COE_CR = 0x%08x", read_buf);
	return 0;
}

static int smsc95xx_ethtool_get_eeprom_len(struct net_device *net)
{
	return MAX_EEPROM_SIZE;
}

static int smsc95xx_ethtool_get_eeprom(struct net_device *netdev,
				       struct ethtool_eeprom *ee, u8 *data)
{
	struct usbnet *dev = netdev_priv(netdev);

	ee->magic = LAN95XX_EEPROM_MAGIC;

	return smsc95xx_read_eeprom(dev, ee->offset, ee->len, data);
}

static int smsc95xx_ethtool_set_eeprom(struct net_device *netdev,
				       struct ethtool_eeprom *ee, u8 *data)
{
	struct usbnet *dev = netdev_priv(netdev);

	if (ee->magic != LAN95XX_EEPROM_MAGIC) {
		devwarn(dev, "EEPROM: magic value mismatch, magic = 0x%x",
			ee->magic);
		return -EINVAL;
	}

	return smsc95xx_write_eeprom(dev, ee->offset, ee->len, data);
}

static u32 smsc95xx_ethtool_get_rx_csum(struct net_device *netdev)
{
	struct usbnet *dev = netdev_priv(netdev);
	struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);

	return pdata->use_rx_csum;
}

static int smsc95xx_ethtool_set_rx_csum(struct net_device *netdev, u32 val)
{
	struct usbnet *dev = netdev_priv(netdev);
	struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);

	pdata->use_rx_csum = !!val;

	return smsc95xx_set_csums(dev);
}

static u32 smsc95xx_ethtool_get_tx_csum(struct net_device *netdev)
{
	struct usbnet *dev = netdev_priv(netdev);
	struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);

	return pdata->use_tx_csum;
}

static int smsc95xx_ethtool_set_tx_csum(struct net_device *netdev, u32 val)
{
	struct usbnet *dev = netdev_priv(netdev);
	struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);

	pdata->use_tx_csum = !!val;

	ethtool_op_set_tx_hw_csum(netdev, pdata->use_tx_csum);
	return smsc95xx_set_csums(dev);
}

static struct ethtool_ops smsc95xx_ethtool_ops = {
	.get_link	= usbnet_get_link,
	.nway_reset	= usbnet_nway_reset,
	.get_drvinfo	= usbnet_get_drvinfo,
	.get_msglevel	= usbnet_get_msglevel,
	.set_msglevel	= usbnet_set_msglevel,
	.get_settings	= usbnet_get_settings,
	.set_settings	= usbnet_set_settings,
	.get_eeprom_len	= smsc95xx_ethtool_get_eeprom_len,
	.get_eeprom	= smsc95xx_ethtool_get_eeprom,
	.set_eeprom	= smsc95xx_ethtool_set_eeprom,
	.get_tx_csum	= smsc95xx_ethtool_get_tx_csum,
	.set_tx_csum	= smsc95xx_ethtool_set_tx_csum,
	.get_rx_csum	= smsc95xx_ethtool_get_rx_csum,
	.set_rx_csum	= smsc95xx_ethtool_set_rx_csum,
};

static int smsc95xx_ioctl(struct net_device *netdev, struct ifreq *rq, int cmd)
{
	struct usbnet *dev = netdev_priv(netdev);

	if (!netif_running(netdev))
		return -EINVAL;

	return generic_mii_ioctl(&dev->mii, if_mii(rq), cmd, NULL);
}

static void smsc95xx_init_mac_address(struct usbnet *dev)
{
	/* try reading mac address from EEPROM */
	if (smsc95xx_read_eeprom(dev, EEPROM_MAC_OFFSET, ETH_ALEN,
			dev->net->dev_addr) == 0) {
		if (is_valid_ether_addr(dev->net->dev_addr)) {
			/* eeprom values are valid so use them */
			if (netif_msg_ifup(dev))
				devdbg(dev, "MAC address read from EEPROM");
			return;
		}
	}

	/* no eeprom, or eeprom values are invalid. generate random MAC */
	random_ether_addr(dev->net->dev_addr);
	if (netif_msg_ifup(dev))
		devdbg(dev, "MAC address set to random_ether_addr");
}

static int smsc95xx_set_mac_address(struct usbnet *dev)
{
	u32 addr_lo = dev->net->dev_addr[0] | dev->net->dev_addr[1] << 8 |
		dev->net->dev_addr[2] << 16 | dev->net->dev_addr[3] << 24;
	u32 addr_hi = dev->net->dev_addr[4] | dev->net->dev_addr[5] << 8;
	int ret;

	ret = smsc95xx_write_reg(dev, ADDRL, addr_lo);
	if (ret < 0) {
		devwarn(dev, "Failed to write ADDRL: %d", ret);
		return ret;
	}

	ret = smsc95xx_write_reg(dev, ADDRH, addr_hi);
	if (ret < 0) {
		devwarn(dev, "Failed to write ADDRH: %d", ret);
		return ret;
	}

	return 0;
}

/* starts the TX path */
static void smsc95xx_start_tx_path(struct usbnet *dev)
{
	struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
	unsigned long flags;
	u32 reg_val;

	/* Enable Tx at MAC */
	spin_lock_irqsave(&pdata->mac_cr_lock, flags);
	pdata->mac_cr |= MAC_CR_TXEN_;
	spin_unlock_irqrestore(&pdata->mac_cr_lock, flags);

	smsc95xx_write_reg(dev, MAC_CR, pdata->mac_cr);

	/* Enable Tx at SCSRs */
	reg_val = TX_CFG_ON_;
	smsc95xx_write_reg(dev, TX_CFG, reg_val);
}

/* Starts the Receive path */
static void smsc95xx_start_rx_path(struct usbnet *dev)
{
	struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
	unsigned long flags;

	spin_lock_irqsave(&pdata->mac_cr_lock, flags);
	pdata->mac_cr |= MAC_CR_RXEN_;
	spin_unlock_irqrestore(&pdata->mac_cr_lock, flags);

	smsc95xx_write_reg(dev, MAC_CR, pdata->mac_cr);
}

static int smsc95xx_phy_initialize(struct usbnet *dev)
{
	/* Initialize MII structure */
	dev->mii.dev = dev->net;
	dev->mii.mdio_read = smsc95xx_mdio_read;
	dev->mii.mdio_write = smsc95xx_mdio_write;
	dev->mii.phy_id_mask = 0x1f;
	dev->mii.reg_num_mask = 0x1f;
	dev->mii.phy_id = SMSC95XX_INTERNAL_PHY_ID;

	smsc95xx_mdio_write(dev->net, dev->mii.phy_id, MII_BMCR, BMCR_RESET);
	smsc95xx_mdio_write(dev->net, dev->mii.phy_id, MII_ADVERTISE,
		ADVERTISE_ALL | ADVERTISE_CSMA | ADVERTISE_PAUSE_CAP |
		ADVERTISE_PAUSE_ASYM);

	/* read to clear */
	smsc95xx_mdio_read(dev->net, dev->mii.phy_id, PHY_INT_SRC);

	smsc95xx_mdio_write(dev->net, dev->mii.phy_id, PHY_INT_MASK,
		PHY_INT_MASK_DEFAULT_);
	mii_nway_restart(&dev->mii);

	if (netif_msg_ifup(dev))
		devdbg(dev, "phy initialised succesfully");
	return 0;
}

static int smsc95xx_reset(struct usbnet *dev)
{
	struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
	struct net_device *netdev = dev->net;
	u32 read_buf, write_buf, burst_cap;
	int ret = 0, timeout;

	if (netif_msg_ifup(dev))
		devdbg(dev, "entering smsc95xx_reset");

	write_buf = HW_CFG_LRST_;
	ret = smsc95xx_write_reg(dev, HW_CFG, write_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to write HW_CFG_LRST_ bit in HW_CFG "
			"register, ret = %d", ret);
		return ret;
	}

	timeout = 0;
	do {
		ret = smsc95xx_read_reg(dev, HW_CFG, &read_buf);
		if (ret < 0) {
			devwarn(dev, "Failed to read HW_CFG: %d", ret);
			return ret;
		}
		msleep(10);
		timeout++;
	} while ((read_buf & HW_CFG_LRST_) && (timeout < 100));

	if (timeout >= 100) {
		devwarn(dev, "timeout waiting for completion of Lite Reset");
		return ret;
	}

	write_buf = PM_CTL_PHY_RST_;
	ret = smsc95xx_write_reg(dev, PM_CTRL, write_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to write PM_CTRL: %d", ret);
		return ret;
	}

	timeout = 0;
	do {
		ret = smsc95xx_read_reg(dev, PM_CTRL, &read_buf);
		if (ret < 0) {
			devwarn(dev, "Failed to read PM_CTRL: %d", ret);
			return ret;
		}
		msleep(10);
		timeout++;
	} while ((read_buf & PM_CTL_PHY_RST_) && (timeout < 100));

	if (timeout >= 100) {
		devwarn(dev, "timeout waiting for PHY Reset");
		return ret;
	}

	smsc95xx_init_mac_address(dev);

	ret = smsc95xx_set_mac_address(dev);
	if (ret < 0)
		return ret;

	if (netif_msg_ifup(dev))
		devdbg(dev, "MAC Address: %pM", dev->net->dev_addr);

	ret = smsc95xx_read_reg(dev, HW_CFG, &read_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to read HW_CFG: %d", ret);
		return ret;
	}

	if (netif_msg_ifup(dev))
		devdbg(dev, "Read Value from HW_CFG : 0x%08x", read_buf);

	read_buf |= HW_CFG_BIR_;

	ret = smsc95xx_write_reg(dev, HW_CFG, read_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to write HW_CFG_BIR_ bit in HW_CFG "
			"register, ret = %d", ret);
		return ret;
	}

	ret = smsc95xx_read_reg(dev, HW_CFG, &read_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to read HW_CFG: %d", ret);
		return ret;
	}
	if (netif_msg_ifup(dev))
		devdbg(dev, "Read Value from HW_CFG after writing "
			"HW_CFG_BIR_: 0x%08x", read_buf);

	if (!turbo_mode) {
		burst_cap = 0;
		dev->rx_urb_size = MAX_SINGLE_PACKET_SIZE;
	} else if (dev->udev->speed == USB_SPEED_HIGH) {
		burst_cap = DEFAULT_HS_BURST_CAP_SIZE / HS_USB_PKT_SIZE;
		dev->rx_urb_size = DEFAULT_HS_BURST_CAP_SIZE;
	} else {
		burst_cap = DEFAULT_FS_BURST_CAP_SIZE / FS_USB_PKT_SIZE;
		dev->rx_urb_size = DEFAULT_FS_BURST_CAP_SIZE;
	}

	if (netif_msg_ifup(dev))
		devdbg(dev, "rx_urb_size=%ld", (ulong)dev->rx_urb_size);

	ret = smsc95xx_write_reg(dev, BURST_CAP, burst_cap);
	if (ret < 0) {
		devwarn(dev, "Failed to write BURST_CAP: %d", ret);
		return ret;
	}

	ret = smsc95xx_read_reg(dev, BURST_CAP, &read_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to read BURST_CAP: %d", ret);
		return ret;
	}
	if (netif_msg_ifup(dev))
		devdbg(dev, "Read Value from BURST_CAP after writing: 0x%08x",
			read_buf);

	read_buf = DEFAULT_BULK_IN_DELAY;
	ret = smsc95xx_write_reg(dev, BULK_IN_DLY, read_buf);
	if (ret < 0) {
		devwarn(dev, "ret = %d", ret);
		return ret;
	}

	ret = smsc95xx_read_reg(dev, BULK_IN_DLY, &read_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to read BULK_IN_DLY: %d", ret);
		return ret;
	}
	if (netif_msg_ifup(dev))
		devdbg(dev, "Read Value from BULK_IN_DLY after writing: "
			"0x%08x", read_buf);

	ret = smsc95xx_read_reg(dev, HW_CFG, &read_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to read HW_CFG: %d", ret);
		return ret;
	}
	if (netif_msg_ifup(dev))
		devdbg(dev, "Read Value from HW_CFG: 0x%08x", read_buf);

	if (turbo_mode)
		read_buf |= (HW_CFG_MEF_ | HW_CFG_BCE_);

	read_buf &= ~HW_CFG_RXDOFF_;

	/* set Rx data offset=2, Make IP header aligns on word boundary. */
	read_buf |= NET_IP_ALIGN << 9;

	ret = smsc95xx_write_reg(dev, HW_CFG, read_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to write HW_CFG register, ret=%d", ret);
		return ret;
	}

	ret = smsc95xx_read_reg(dev, HW_CFG, &read_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to read HW_CFG: %d", ret);
		return ret;
	}
	if (netif_msg_ifup(dev))
		devdbg(dev, "Read Value from HW_CFG after writing: 0x%08x",
			read_buf);

	write_buf = 0xFFFFFFFF;
	ret = smsc95xx_write_reg(dev, INT_STS, write_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to write INT_STS register, ret=%d", ret);
		return ret;
	}

	ret = smsc95xx_read_reg(dev, ID_REV, &read_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to read ID_REV: %d", ret);
		return ret;
	}
	if (netif_msg_ifup(dev))
		devdbg(dev, "ID_REV = 0x%08x", read_buf);

	/* Configure GPIO pins as LED outputs */
	write_buf = LED_GPIO_CFG_SPD_LED | LED_GPIO_CFG_LNK_LED |
		LED_GPIO_CFG_FDX_LED;
	ret = smsc95xx_write_reg(dev, LED_GPIO_CFG, write_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to write LED_GPIO_CFG register, ret=%d",
			ret);
		return ret;
	}

	/* Init Tx */
	write_buf = 0;
	ret = smsc95xx_write_reg(dev, FLOW, write_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to write FLOW: %d", ret);
		return ret;
	}

	read_buf = AFC_CFG_DEFAULT;
	ret = smsc95xx_write_reg(dev, AFC_CFG, read_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to write AFC_CFG: %d", ret);
		return ret;
	}

	/* Don't need mac_cr_lock during initialisation */
	ret = smsc95xx_read_reg(dev, MAC_CR, &pdata->mac_cr);
	if (ret < 0) {
		devwarn(dev, "Failed to read MAC_CR: %d", ret);
		return ret;
	}

	/* Init Rx */
	/* Set Vlan */
	write_buf = (u32)ETH_P_8021Q;
	ret = smsc95xx_write_reg(dev, VLAN1, write_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to write VAN1: %d", ret);
		return ret;
	}

	/* Enable or disable checksum offload engines */
	ethtool_op_set_tx_hw_csum(netdev, pdata->use_tx_csum);
	ret = smsc95xx_set_csums(dev);
	if (ret < 0) {
		devwarn(dev, "Failed to set csum offload: %d", ret);
		return ret;
	}

	smsc95xx_set_multicast(dev->net);

	if (smsc95xx_phy_initialize(dev) < 0)
		return -EIO;

	ret = smsc95xx_read_reg(dev, INT_EP_CTL, &read_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to read INT_EP_CTL: %d", ret);
		return ret;
	}

	/* enable PHY interrupts */
	read_buf |= INT_EP_CTL_PHY_INT_;

	ret = smsc95xx_write_reg(dev, INT_EP_CTL, read_buf);
	if (ret < 0) {
		devwarn(dev, "Failed to write INT_EP_CTL: %d", ret);
		return ret;
	}

	smsc95xx_start_tx_path(dev);
	smsc95xx_start_rx_path(dev);

	if (netif_msg_ifup(dev))
		devdbg(dev, "smsc95xx_reset, return 0");
	return 0;
}

static const struct net_device_ops smsc95xx_netdev_ops = {
	.ndo_open		= usbnet_open,
	.ndo_stop		= usbnet_stop,
	.ndo_start_xmit		= usbnet_start_xmit,
	.ndo_tx_timeout		= usbnet_tx_timeout,
	.ndo_change_mtu		= usbnet_change_mtu,
	.ndo_set_mac_address 	= eth_mac_addr,
	.ndo_validate_addr	= eth_validate_addr,
	.ndo_do_ioctl 		= smsc95xx_ioctl,
	.ndo_set_multicast_list = smsc95xx_set_multicast,
};

static int smsc95xx_bind(struct usbnet *dev, struct usb_interface *intf)
{
	struct smsc95xx_priv *pdata = NULL;
	int ret;

	printk(KERN_INFO SMSC_CHIPNAME " v" SMSC_DRIVER_VERSION "\n");

	ret = usbnet_get_endpoints(dev, intf);
	if (ret < 0) {
		devwarn(dev, "usbnet_get_endpoints failed: %d", ret);
		return ret;
	}

	dev->data[0] = (unsigned long)kzalloc(sizeof(struct smsc95xx_priv),
		GFP_KERNEL);

	pdata = (struct smsc95xx_priv *)(dev->data[0]);
	if (!pdata) {
		devwarn(dev, "Unable to allocate struct smsc95xx_priv");
		return -ENOMEM;
	}

	spin_lock_init(&pdata->mac_cr_lock);

	pdata->use_tx_csum = DEFAULT_TX_CSUM_ENABLE;
	pdata->use_rx_csum = DEFAULT_RX_CSUM_ENABLE;

	/* Init all registers */
	ret = smsc95xx_reset(dev);

	dev->net->netdev_ops = &smsc95xx_netdev_ops;
	dev->net->ethtool_ops = &smsc95xx_ethtool_ops;
	dev->net->flags |= IFF_MULTICAST;
	dev->net->hard_header_len += SMSC95XX_TX_OVERHEAD;
	return 0;
}

static void smsc95xx_unbind(struct usbnet *dev, struct usb_interface *intf)
{
	struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
	if (pdata) {
		if (netif_msg_ifdown(dev))
			devdbg(dev, "free pdata");
		kfree(pdata);
		pdata = NULL;
		dev->data[0] = 0;
	}
}

static void smsc95xx_rx_csum_offload(struct sk_buff *skb)
{
	skb->csum = *(u16 *)(skb_tail_pointer(skb) - 2);
	skb->ip_summed = CHECKSUM_COMPLETE;
	skb_trim(skb, skb->len - 2);
}

static int smsc95xx_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
{
	struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);

	while (skb->len > 0) {
		u32 header, align_count;
		struct sk_buff *ax_skb;
		unsigned char *packet;
		u16 size;

		memcpy(&header, skb->data, sizeof(header));
		le32_to_cpus(&header);
		skb_pull(skb, 4 + NET_IP_ALIGN);
		packet = skb->data;

		/* get the packet length */
		size = (u16)((header & RX_STS_FL_) >> 16);
		align_count = (4 - ((size + NET_IP_ALIGN) % 4)) % 4;

		if (unlikely(header & RX_STS_ES_)) {
			if (netif_msg_rx_err(dev))
				devdbg(dev, "Error header=0x%08x", header);
			dev->net->stats.rx_errors++;
			dev->net->stats.rx_dropped++;

			if (header & RX_STS_CRC_) {
				dev->net->stats.rx_crc_errors++;
			} else {
				if (header & (RX_STS_TL_ | RX_STS_RF_))
					dev->net->stats.rx_frame_errors++;

				if ((header & RX_STS_LE_) &&
					(!(header & RX_STS_FT_)))
					dev->net->stats.rx_length_errors++;
			}
		} else {
			/* ETH_FRAME_LEN + 4(CRC) + 2(COE) + 4(Vlan) */
			if (unlikely(size > (ETH_FRAME_LEN + 12))) {
				if (netif_msg_rx_err(dev))
					devdbg(dev, "size err header=0x%08x",
						header);
				return 0;
			}

			/* last frame in this batch */
			if (skb->len == size) {
				if (pdata->use_rx_csum)
					smsc95xx_rx_csum_offload(skb);
				skb_trim(skb, skb->len - 4); /* remove fcs */
				skb->truesize = size + sizeof(struct sk_buff);

				return 1;
			}

			ax_skb = skb_clone(skb, GFP_ATOMIC);
			if (unlikely(!ax_skb)) {
				devwarn(dev, "Error allocating skb");
				return 0;
			}

			ax_skb->len = size;
			ax_skb->data = packet;
			skb_set_tail_pointer(ax_skb, size);

			if (pdata->use_rx_csum)
				smsc95xx_rx_csum_offload(ax_skb);
			skb_trim(ax_skb, ax_skb->len - 4); /* remove fcs */
			ax_skb->truesize = size + sizeof(struct sk_buff);

			usbnet_skb_return(dev, ax_skb);
		}

		skb_pull(skb, size);

		/* padding bytes before the next frame starts */
		if (skb->len)
			skb_pull(skb, align_count);
	}

	if (unlikely(skb->len < 0)) {
		devwarn(dev, "invalid rx length<0 %d", skb->len);
		return 0;
	}

	return 1;
}

static u32 smsc95xx_calc_csum_preamble(struct sk_buff *skb)
{
	int len = skb->data - skb->head;
	u16 high_16 = (u16)(skb->csum_offset + skb->csum_start - len);
	u16 low_16 = (u16)(skb->csum_start - len);
	return (high_16 << 16) | low_16;
}

static struct sk_buff *smsc95xx_tx_fixup(struct usbnet *dev,
					 struct sk_buff *skb, gfp_t flags)
{
	struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
	bool csum = pdata->use_tx_csum && (skb->ip_summed == CHECKSUM_PARTIAL);
	int overhead = csum ? SMSC95XX_TX_OVERHEAD_CSUM : SMSC95XX_TX_OVERHEAD;
	u32 tx_cmd_a, tx_cmd_b;

	/* We do not advertise SG, so skbs should be already linearized */
	BUG_ON(skb_shinfo(skb)->nr_frags);

	if (skb_headroom(skb) < overhead) {
		struct sk_buff *skb2 = skb_copy_expand(skb,
			overhead, 0, flags);
		dev_kfree_skb_any(skb);
		skb = skb2;
		if (!skb)
			return NULL;
	}

	if (csum) {
		u32 csum_preamble = smsc95xx_calc_csum_preamble(skb);
		skb_push(skb, 4);
		memcpy(skb->data, &csum_preamble, 4);
	}

	skb_push(skb, 4);
	tx_cmd_b = (u32)(skb->len - 4);
	if (csum)
		tx_cmd_b |= TX_CMD_B_CSUM_ENABLE;
	cpu_to_le32s(&tx_cmd_b);
	memcpy(skb->data, &tx_cmd_b, 4);

	skb_push(skb, 4);
	tx_cmd_a = (u32)(skb->len - 8) | TX_CMD_A_FIRST_SEG_ |
		TX_CMD_A_LAST_SEG_;
	cpu_to_le32s(&tx_cmd_a);
	memcpy(skb->data, &tx_cmd_a, 4);

	return skb;
}

static const struct driver_info smsc95xx_info = {
	.description	= "smsc95xx USB 2.0 Ethernet",
	.bind		= smsc95xx_bind,
	.unbind		= smsc95xx_unbind,
	.link_reset	= smsc95xx_link_reset,
	.reset		= smsc95xx_reset,
	.rx_fixup	= smsc95xx_rx_fixup,
	.tx_fixup	= smsc95xx_tx_fixup,
	.status		= smsc95xx_status,
	.flags		= FLAG_ETHER,
};

static const struct usb_device_id products[] = {
	{
		/* SMSC9500 USB Ethernet Device */
		USB_DEVICE(0x0424, 0x9500),
		.driver_info = (unsigned long) &smsc95xx_info,
	},
	{
		/* SMSC9512/9514 USB Hub & Ethernet Device */
		USB_DEVICE(0x0424, 0xec00),
		.driver_info = (unsigned long) &smsc95xx_info,
	},
	{ },		/* END */
};
MODULE_DEVICE_TABLE(usb, products);

static struct usb_driver smsc95xx_driver = {
	.name		= "smsc95xx",
	.id_table	= products,
	.probe		= usbnet_probe,
	.suspend	= usbnet_suspend,
	.resume		= usbnet_resume,
	.disconnect	= usbnet_disconnect,
};

static int __init smsc95xx_init(void)
{
	return usb_register(&smsc95xx_driver);
}
module_init(smsc95xx_init);

static void __exit smsc95xx_exit(void)
{
	usb_deregister(&smsc95xx_driver);
}
module_exit(smsc95xx_exit);

MODULE_AUTHOR("Nancy Lin");
MODULE_AUTHOR("Steve Glendinning <steve.glendinning@smsc.com>");
MODULE_DESCRIPTION("SMSC95XX USB 2.0 Ethernet Devices");
MODULE_LICENSE("GPL");