aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/ethernet/xilinx/xilinx_emaclite.c
blob: 63a2d1bcccfbce602f3ec47202253a72a39820ea (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
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Xilinx EmacLite Linux driver for the Xilinx Ethernet MAC Lite device.
 *
 * This is a new flat driver which is based on the original emac_lite
 * driver from John Williams <john.williams@xilinx.com>.
 *
 * 2007 - 2013 (c) Xilinx, Inc.
 */

#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/ethtool.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/of_mdio.h>
#include <linux/of_net.h>
#include <linux/phy.h>
#include <linux/interrupt.h>
#include <linux/iopoll.h>

#define DRIVER_NAME "xilinx_emaclite"

/* Register offsets for the EmacLite Core */
#define XEL_TXBUFF_OFFSET	0x0		/* Transmit Buffer */
#define XEL_MDIOADDR_OFFSET	0x07E4		/* MDIO Address Register */
#define XEL_MDIOWR_OFFSET	0x07E8		/* MDIO Write Data Register */
#define XEL_MDIORD_OFFSET	0x07EC		/* MDIO Read Data Register */
#define XEL_MDIOCTRL_OFFSET	0x07F0		/* MDIO Control Register */
#define XEL_GIER_OFFSET		0x07F8		/* GIE Register */
#define XEL_TSR_OFFSET		0x07FC		/* Tx status */
#define XEL_TPLR_OFFSET		0x07F4		/* Tx packet length */

#define XEL_RXBUFF_OFFSET	0x1000		/* Receive Buffer */
#define XEL_RPLR_OFFSET		0x100C		/* Rx packet length */
#define XEL_RSR_OFFSET		0x17FC		/* Rx status */

#define XEL_BUFFER_OFFSET	0x0800		/* Next Tx/Rx buffer's offset */

/* MDIO Address Register Bit Masks */
#define XEL_MDIOADDR_REGADR_MASK  0x0000001F	/* Register Address */
#define XEL_MDIOADDR_PHYADR_MASK  0x000003E0	/* PHY Address */
#define XEL_MDIOADDR_PHYADR_SHIFT 5
#define XEL_MDIOADDR_OP_MASK	  0x00000400	/* RD/WR Operation */

/* MDIO Write Data Register Bit Masks */
#define XEL_MDIOWR_WRDATA_MASK	  0x0000FFFF	/* Data to be Written */

/* MDIO Read Data Register Bit Masks */
#define XEL_MDIORD_RDDATA_MASK	  0x0000FFFF	/* Data to be Read */

/* MDIO Control Register Bit Masks */
#define XEL_MDIOCTRL_MDIOSTS_MASK 0x00000001	/* MDIO Status Mask */
#define XEL_MDIOCTRL_MDIOEN_MASK  0x00000008	/* MDIO Enable */

/* Global Interrupt Enable Register (GIER) Bit Masks */
#define XEL_GIER_GIE_MASK	0x80000000	/* Global Enable */

/* Transmit Status Register (TSR) Bit Masks */
#define XEL_TSR_XMIT_BUSY_MASK	 0x00000001	/* Tx complete */
#define XEL_TSR_PROGRAM_MASK	 0x00000002	/* Program the MAC address */
#define XEL_TSR_XMIT_IE_MASK	 0x00000008	/* Tx interrupt enable bit */
#define XEL_TSR_XMIT_ACTIVE_MASK 0x80000000	/* Buffer is active, SW bit
						 * only. This is not documented
						 * in the HW spec
						 */

/* Define for programming the MAC address into the EmacLite */
#define XEL_TSR_PROG_MAC_ADDR	(XEL_TSR_XMIT_BUSY_MASK | XEL_TSR_PROGRAM_MASK)

/* Receive Status Register (RSR) */
#define XEL_RSR_RECV_DONE_MASK	0x00000001	/* Rx complete */
#define XEL_RSR_RECV_IE_MASK	0x00000008	/* Rx interrupt enable bit */

/* Transmit Packet Length Register (TPLR) */
#define XEL_TPLR_LENGTH_MASK	0x0000FFFF	/* Tx packet length */

/* Receive Packet Length Register (RPLR) */
#define XEL_RPLR_LENGTH_MASK	0x0000FFFF	/* Rx packet length */

#define XEL_HEADER_OFFSET	12		/* Offset to length field */
#define XEL_HEADER_SHIFT	16		/* Shift value for length */

/* General Ethernet Definitions */
#define XEL_ARP_PACKET_SIZE		28	/* Max ARP packet size */
#define XEL_HEADER_IP_LENGTH_OFFSET	16	/* IP Length Offset */



#define TX_TIMEOUT		(60 * HZ)	/* Tx timeout is 60 seconds. */
#define ALIGNMENT		4

/* BUFFER_ALIGN(adr) calculates the number of bytes to the next alignment. */
#define BUFFER_ALIGN(adr) ((ALIGNMENT - ((u32)adr)) % ALIGNMENT)

#ifdef __BIG_ENDIAN
#define xemaclite_readl		ioread32be
#define xemaclite_writel	iowrite32be
#else
#define xemaclite_readl		ioread32
#define xemaclite_writel	iowrite32
#endif

/**
 * struct net_local - Our private per device data
 * @ndev:		instance of the network device
 * @tx_ping_pong:	indicates whether Tx Pong buffer is configured in HW
 * @rx_ping_pong:	indicates whether Rx Pong buffer is configured in HW
 * @next_tx_buf_to_use:	next Tx buffer to write to
 * @next_rx_buf_to_use:	next Rx buffer to read from
 * @base_addr:		base address of the Emaclite device
 * @reset_lock:		lock used for synchronization
 * @deferred_skb:	holds an skb (for transmission at a later time) when the
 *			Tx buffer is not free
 * @phy_dev:		pointer to the PHY device
 * @phy_node:		pointer to the PHY device node
 * @mii_bus:		pointer to the MII bus
 * @last_link:		last link status
 */
struct net_local {

	struct net_device *ndev;

	bool tx_ping_pong;
	bool rx_ping_pong;
	u32 next_tx_buf_to_use;
	u32 next_rx_buf_to_use;
	void __iomem *base_addr;

	spinlock_t reset_lock;
	struct sk_buff *deferred_skb;

	struct phy_device *phy_dev;
	struct device_node *phy_node;

	struct mii_bus *mii_bus;

	int last_link;
};


/*************************/
/* EmacLite driver calls */
/*************************/

/**
 * xemaclite_enable_interrupts - Enable the interrupts for the EmacLite device
 * @drvdata:	Pointer to the Emaclite device private data
 *
 * This function enables the Tx and Rx interrupts for the Emaclite device along
 * with the Global Interrupt Enable.
 */
static void xemaclite_enable_interrupts(struct net_local *drvdata)
{
	u32 reg_data;

	/* Enable the Tx interrupts for the first Buffer */
	reg_data = xemaclite_readl(drvdata->base_addr + XEL_TSR_OFFSET);
	xemaclite_writel(reg_data | XEL_TSR_XMIT_IE_MASK,
			 drvdata->base_addr + XEL_TSR_OFFSET);

	/* Enable the Rx interrupts for the first buffer */
	xemaclite_writel(XEL_RSR_RECV_IE_MASK, drvdata->base_addr + XEL_RSR_OFFSET);

	/* Enable the Global Interrupt Enable */
	xemaclite_writel(XEL_GIER_GIE_MASK, drvdata->base_addr + XEL_GIER_OFFSET);
}

/**
 * xemaclite_disable_interrupts - Disable the interrupts for the EmacLite device
 * @drvdata:	Pointer to the Emaclite device private data
 *
 * This function disables the Tx and Rx interrupts for the Emaclite device,
 * along with the Global Interrupt Enable.
 */
static void xemaclite_disable_interrupts(struct net_local *drvdata)
{
	u32 reg_data;

	/* Disable the Global Interrupt Enable */
	xemaclite_writel(XEL_GIER_GIE_MASK, drvdata->base_addr + XEL_GIER_OFFSET);

	/* Disable the Tx interrupts for the first buffer */
	reg_data = xemaclite_readl(drvdata->base_addr + XEL_TSR_OFFSET);
	xemaclite_writel(reg_data & (~XEL_TSR_XMIT_IE_MASK),
			 drvdata->base_addr + XEL_TSR_OFFSET);

	/* Disable the Rx interrupts for the first buffer */
	reg_data = xemaclite_readl(drvdata->base_addr + XEL_RSR_OFFSET);
	xemaclite_writel(reg_data & (~XEL_RSR_RECV_IE_MASK),
			 drvdata->base_addr + XEL_RSR_OFFSET);
}

/**
 * xemaclite_aligned_write - Write from 16-bit aligned to 32-bit aligned address
 * @src_ptr:	Void pointer to the 16-bit aligned source address
 * @dest_ptr:	Pointer to the 32-bit aligned destination address
 * @length:	Number bytes to write from source to destination
 *
 * This function writes data from a 16-bit aligned buffer to a 32-bit aligned
 * address in the EmacLite device.
 */
static void xemaclite_aligned_write(void *src_ptr, u32 *dest_ptr,
				    unsigned length)
{
	u32 align_buffer;
	u32 *to_u32_ptr;
	u16 *from_u16_ptr, *to_u16_ptr;

	to_u32_ptr = dest_ptr;
	from_u16_ptr = src_ptr;
	align_buffer = 0;

	for (; length > 3; length -= 4) {
		to_u16_ptr = (u16 *)&align_buffer;
		*to_u16_ptr++ = *from_u16_ptr++;
		*to_u16_ptr++ = *from_u16_ptr++;

		/* This barrier resolves occasional issues seen around
		 * cases where the data is not properly flushed out
		 * from the processor store buffers to the destination
		 * memory locations.
		 */
		wmb();

		/* Output a word */
		*to_u32_ptr++ = align_buffer;
	}
	if (length) {
		u8 *from_u8_ptr, *to_u8_ptr;

		/* Set up to output the remaining data */
		align_buffer = 0;
		to_u8_ptr = (u8 *)&align_buffer;
		from_u8_ptr = (u8 *)from_u16_ptr;

		/* Output the remaining data */
		for (; length > 0; length--)
			*to_u8_ptr++ = *from_u8_ptr++;

		/* This barrier resolves occasional issues seen around
		 * cases where the data is not properly flushed out
		 * from the processor store buffers to the destination
		 * memory locations.
		 */
		wmb();
		*to_u32_ptr = align_buffer;
	}
}

/**
 * xemaclite_aligned_read - Read from 32-bit aligned to 16-bit aligned buffer
 * @src_ptr:	Pointer to the 32-bit aligned source address
 * @dest_ptr:	Pointer to the 16-bit aligned destination address
 * @length:	Number bytes to read from source to destination
 *
 * This function reads data from a 32-bit aligned address in the EmacLite device
 * to a 16-bit aligned buffer.
 */
static void xemaclite_aligned_read(u32 *src_ptr, u8 *dest_ptr,
				   unsigned length)
{
	u16 *to_u16_ptr, *from_u16_ptr;
	u32 *from_u32_ptr;
	u32 align_buffer;

	from_u32_ptr = src_ptr;
	to_u16_ptr = (u16 *)dest_ptr;

	for (; length > 3; length -= 4) {
		/* Copy each word into the temporary buffer */
		align_buffer = *from_u32_ptr++;
		from_u16_ptr = (u16 *)&align_buffer;

		/* Read data from source */
		*to_u16_ptr++ = *from_u16_ptr++;
		*to_u16_ptr++ = *from_u16_ptr++;
	}

	if (length) {
		u8 *to_u8_ptr, *from_u8_ptr;

		/* Set up to read the remaining data */
		to_u8_ptr = (u8 *)to_u16_ptr;
		align_buffer = *from_u32_ptr++;
		from_u8_ptr = (u8 *)&align_buffer;

		/* Read the remaining data */
		for (; length > 0; length--)
			*to_u8_ptr = *from_u8_ptr;
	}
}

/**
 * xemaclite_send_data - Send an Ethernet frame
 * @drvdata:	Pointer to the Emaclite device private data
 * @data:	Pointer to the data to be sent
 * @byte_count:	Total frame size, including header
 *
 * This function checks if the Tx buffer of the Emaclite device is free to send
 * data. If so, it fills the Tx buffer with data for transmission. Otherwise, it
 * returns an error.
 *
 * Return:	0 upon success or -1 if the buffer(s) are full.
 *
 * Note:	The maximum Tx packet size can not be more than Ethernet header
 *		(14 Bytes) + Maximum MTU (1500 bytes). This is excluding FCS.
 */
static int xemaclite_send_data(struct net_local *drvdata, u8 *data,
			       unsigned int byte_count)
{
	u32 reg_data;
	void __iomem *addr;

	/* Determine the expected Tx buffer address */
	addr = drvdata->base_addr + drvdata->next_tx_buf_to_use;

	/* If the length is too large, truncate it */
	if (byte_count > ETH_FRAME_LEN)
		byte_count = ETH_FRAME_LEN;

	/* Check if the expected buffer is available */
	reg_data = xemaclite_readl(addr + XEL_TSR_OFFSET);
	if ((reg_data & (XEL_TSR_XMIT_BUSY_MASK |
	     XEL_TSR_XMIT_ACTIVE_MASK)) == 0) {

		/* Switch to next buffer if configured */
		if (drvdata->tx_ping_pong != 0)
			drvdata->next_tx_buf_to_use ^= XEL_BUFFER_OFFSET;
	} else if (drvdata->tx_ping_pong != 0) {
		/* If the expected buffer is full, try the other buffer,
		 * if it is configured in HW
		 */

		addr = (void __iomem __force *)((u32 __force)addr ^
						 XEL_BUFFER_OFFSET);
		reg_data = xemaclite_readl(addr + XEL_TSR_OFFSET);

		if ((reg_data & (XEL_TSR_XMIT_BUSY_MASK |
		     XEL_TSR_XMIT_ACTIVE_MASK)) != 0)
			return -1; /* Buffers were full, return failure */
	} else
		return -1; /* Buffer was full, return failure */

	/* Write the frame to the buffer */
	xemaclite_aligned_write(data, (u32 __force *)addr, byte_count);

	xemaclite_writel((byte_count & XEL_TPLR_LENGTH_MASK),
			 addr + XEL_TPLR_OFFSET);

	/* Update the Tx Status Register to indicate that there is a
	 * frame to send. Set the XEL_TSR_XMIT_ACTIVE_MASK flag which
	 * is used by the interrupt handler to check whether a frame
	 * has been transmitted
	 */
	reg_data = xemaclite_readl(addr + XEL_TSR_OFFSET);
	reg_data |= (XEL_TSR_XMIT_BUSY_MASK | XEL_TSR_XMIT_ACTIVE_MASK);
	xemaclite_writel(reg_data, addr + XEL_TSR_OFFSET);

	return 0;
}

/**
 * xemaclite_recv_data - Receive a frame
 * @drvdata:	Pointer to the Emaclite device private data
 * @data:	Address where the data is to be received
 * @maxlen:    Maximum supported ethernet packet length
 *
 * This function is intended to be called from the interrupt context or
 * with a wrapper which waits for the receive frame to be available.
 *
 * Return:	Total number of bytes received
 */
static u16 xemaclite_recv_data(struct net_local *drvdata, u8 *data, int maxlen)
{
	void __iomem *addr;
	u16 length, proto_type;
	u32 reg_data;

	/* Determine the expected buffer address */
	addr = (drvdata->base_addr + drvdata->next_rx_buf_to_use);

	/* Verify which buffer has valid data */
	reg_data = xemaclite_readl(addr + XEL_RSR_OFFSET);

	if ((reg_data & XEL_RSR_RECV_DONE_MASK) == XEL_RSR_RECV_DONE_MASK) {
		if (drvdata->rx_ping_pong != 0)
			drvdata->next_rx_buf_to_use ^= XEL_BUFFER_OFFSET;
	} else {
		/* The instance is out of sync, try other buffer if other
		 * buffer is configured, return 0 otherwise. If the instance is
		 * out of sync, do not update the 'next_rx_buf_to_use' since it
		 * will correct on subsequent calls
		 */
		if (drvdata->rx_ping_pong != 0)
			addr = (void __iomem __force *)((u32 __force)addr ^
							 XEL_BUFFER_OFFSET);
		else
			return 0;	/* No data was available */

		/* Verify that buffer has valid data */
		reg_data = xemaclite_readl(addr + XEL_RSR_OFFSET);
		if ((reg_data & XEL_RSR_RECV_DONE_MASK) !=
		     XEL_RSR_RECV_DONE_MASK)
			return 0;	/* No data was available */
	}

	/* Get the protocol type of the ethernet frame that arrived
	 */
	proto_type = ((ntohl(xemaclite_readl(addr + XEL_HEADER_OFFSET +
			XEL_RXBUFF_OFFSET)) >> XEL_HEADER_SHIFT) &
			XEL_RPLR_LENGTH_MASK);

	/* Check if received ethernet frame is a raw ethernet frame
	 * or an IP packet or an ARP packet
	 */
	if (proto_type > ETH_DATA_LEN) {

		if (proto_type == ETH_P_IP) {
			length = ((ntohl(xemaclite_readl(addr +
					XEL_HEADER_IP_LENGTH_OFFSET +
					XEL_RXBUFF_OFFSET)) >>
					XEL_HEADER_SHIFT) &
					XEL_RPLR_LENGTH_MASK);
			length = min_t(u16, length, ETH_DATA_LEN);
			length += ETH_HLEN + ETH_FCS_LEN;

		} else if (proto_type == ETH_P_ARP)
			length = XEL_ARP_PACKET_SIZE + ETH_HLEN + ETH_FCS_LEN;
		else
			/* Field contains type other than IP or ARP, use max
			 * frame size and let user parse it
			 */
			length = ETH_FRAME_LEN + ETH_FCS_LEN;
	} else
		/* Use the length in the frame, plus the header and trailer */
		length = proto_type + ETH_HLEN + ETH_FCS_LEN;

	if (WARN_ON(length > maxlen))
		length = maxlen;

	/* Read from the EmacLite device */
	xemaclite_aligned_read((u32 __force *)(addr + XEL_RXBUFF_OFFSET),
				data, length);

	/* Acknowledge the frame */
	reg_data = xemaclite_readl(addr + XEL_RSR_OFFSET);
	reg_data &= ~XEL_RSR_RECV_DONE_MASK;
	xemaclite_writel(reg_data, addr + XEL_RSR_OFFSET);

	return length;
}

/**
 * xemaclite_update_address - Update the MAC address in the device
 * @drvdata:	Pointer to the Emaclite device private data
 * @address_ptr:Pointer to the MAC address (MAC address is a 48-bit value)
 *
 * Tx must be idle and Rx should be idle for deterministic results.
 * It is recommended that this function should be called after the
 * initialization and before transmission of any packets from the device.
 * The MAC address can be programmed using any of the two transmit
 * buffers (if configured).
 */
static void xemaclite_update_address(struct net_local *drvdata,
				     u8 *address_ptr)
{
	void __iomem *addr;
	u32 reg_data;

	/* Determine the expected Tx buffer address */
	addr = drvdata->base_addr + drvdata->next_tx_buf_to_use;

	xemaclite_aligned_write(address_ptr, (u32 __force *)addr, ETH_ALEN);

	xemaclite_writel(ETH_ALEN, addr + XEL_TPLR_OFFSET);

	/* Update the MAC address in the EmacLite */
	reg_data = xemaclite_readl(addr + XEL_TSR_OFFSET);
	xemaclite_writel(reg_data | XEL_TSR_PROG_MAC_ADDR, addr + XEL_TSR_OFFSET);

	/* Wait for EmacLite to finish with the MAC address update */
	while ((xemaclite_readl(addr + XEL_TSR_OFFSET) &
		XEL_TSR_PROG_MAC_ADDR) != 0)
		;
}

/**
 * xemaclite_set_mac_address - Set the MAC address for this device
 * @dev:	Pointer to the network device instance
 * @address:	Void pointer to the sockaddr structure
 *
 * This function copies the HW address from the sockaddr strucutre to the
 * net_device structure and updates the address in HW.
 *
 * Return:	Error if the net device is busy or 0 if the addr is set
 *		successfully
 */
static int xemaclite_set_mac_address(struct net_device *dev, void *address)
{
	struct net_local *lp = netdev_priv(dev);
	struct sockaddr *addr = address;

	if (netif_running(dev))
		return -EBUSY;

	memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);
	xemaclite_update_address(lp, dev->dev_addr);
	return 0;
}

/**
 * xemaclite_tx_timeout - Callback for Tx Timeout
 * @dev:	Pointer to the network device
 *
 * This function is called when Tx time out occurs for Emaclite device.
 */
static void xemaclite_tx_timeout(struct net_device *dev)
{
	struct net_local *lp = netdev_priv(dev);
	unsigned long flags;

	dev_err(&lp->ndev->dev, "Exceeded transmit timeout of %lu ms\n",
		TX_TIMEOUT * 1000UL / HZ);

	dev->stats.tx_errors++;

	/* Reset the device */
	spin_lock_irqsave(&lp->reset_lock, flags);

	/* Shouldn't really be necessary, but shouldn't hurt */
	netif_stop_queue(dev);

	xemaclite_disable_interrupts(lp);
	xemaclite_enable_interrupts(lp);

	if (lp->deferred_skb) {
		dev_kfree_skb(lp->deferred_skb);
		lp->deferred_skb = NULL;
		dev->stats.tx_errors++;
	}

	/* To exclude tx timeout */
	netif_trans_update(dev); /* prevent tx timeout */

	/* We're all ready to go. Start the queue */
	netif_wake_queue(dev);
	spin_unlock_irqrestore(&lp->reset_lock, flags);
}

/**********************/
/* Interrupt Handlers */
/**********************/

/**
 * xemaclite_tx_handler - Interrupt handler for frames sent
 * @dev:	Pointer to the network device
 *
 * This function updates the number of packets transmitted and handles the
 * deferred skb, if there is one.
 */
static void xemaclite_tx_handler(struct net_device *dev)
{
	struct net_local *lp = netdev_priv(dev);

	dev->stats.tx_packets++;

	if (!lp->deferred_skb)
		return;

	if (xemaclite_send_data(lp, (u8 *)lp->deferred_skb->data,
				lp->deferred_skb->len))
		return;

	dev->stats.tx_bytes += lp->deferred_skb->len;
	dev_consume_skb_irq(lp->deferred_skb);
	lp->deferred_skb = NULL;
	netif_trans_update(dev); /* prevent tx timeout */
	netif_wake_queue(dev);
}

/**
 * xemaclite_rx_handler- Interrupt handler for frames received
 * @dev:	Pointer to the network device
 *
 * This function allocates memory for a socket buffer, fills it with data
 * received and hands it over to the TCP/IP stack.
 */
static void xemaclite_rx_handler(struct net_device *dev)
{
	struct net_local *lp = netdev_priv(dev);
	struct sk_buff *skb;
	unsigned int align;
	u32 len;

	len = ETH_FRAME_LEN + ETH_FCS_LEN;
	skb = netdev_alloc_skb(dev, len + ALIGNMENT);
	if (!skb) {
		/* Couldn't get memory. */
		dev->stats.rx_dropped++;
		dev_err(&lp->ndev->dev, "Could not allocate receive buffer\n");
		return;
	}

	/* A new skb should have the data halfword aligned, but this code is
	 * here just in case that isn't true. Calculate how many
	 * bytes we should reserve to get the data to start on a word
	 * boundary
	 */
	align = BUFFER_ALIGN(skb->data);
	if (align)
		skb_reserve(skb, align);

	skb_reserve(skb, 2);

	len = xemaclite_recv_data(lp, (u8 *)skb->data, len);

	if (!len) {
		dev->stats.rx_errors++;
		dev_kfree_skb_irq(skb);
		return;
	}

	skb_put(skb, len);	/* Tell the skb how much data we got */

	skb->protocol = eth_type_trans(skb, dev);
	skb_checksum_none_assert(skb);

	dev->stats.rx_packets++;
	dev->stats.rx_bytes += len;

	if (!skb_defer_rx_timestamp(skb))
		netif_rx(skb);	/* Send the packet upstream */
}

/**
 * xemaclite_interrupt - Interrupt handler for this driver
 * @irq:	Irq of the Emaclite device
 * @dev_id:	Void pointer to the network device instance used as callback
 *		reference
 *
 * Return:	IRQ_HANDLED
 *
 * This function handles the Tx and Rx interrupts of the EmacLite device.
 */
static irqreturn_t xemaclite_interrupt(int irq, void *dev_id)
{
	bool tx_complete = false;
	struct net_device *dev = dev_id;
	struct net_local *lp = netdev_priv(dev);
	void __iomem *base_addr = lp->base_addr;
	u32 tx_status;

	/* Check if there is Rx Data available */
	if ((xemaclite_readl(base_addr + XEL_RSR_OFFSET) &
			 XEL_RSR_RECV_DONE_MASK) ||
	    (xemaclite_readl(base_addr + XEL_BUFFER_OFFSET + XEL_RSR_OFFSET)
			 & XEL_RSR_RECV_DONE_MASK))

		xemaclite_rx_handler(dev);

	/* Check if the Transmission for the first buffer is completed */
	tx_status = xemaclite_readl(base_addr + XEL_TSR_OFFSET);
	if (((tx_status & XEL_TSR_XMIT_BUSY_MASK) == 0) &&
		(tx_status & XEL_TSR_XMIT_ACTIVE_MASK) != 0) {

		tx_status &= ~XEL_TSR_XMIT_ACTIVE_MASK;
		xemaclite_writel(tx_status, base_addr + XEL_TSR_OFFSET);

		tx_complete = true;
	}

	/* Check if the Transmission for the second buffer is completed */
	tx_status = xemaclite_readl(base_addr + XEL_BUFFER_OFFSET + XEL_TSR_OFFSET);
	if (((tx_status & XEL_TSR_XMIT_BUSY_MASK) == 0) &&
		(tx_status & XEL_TSR_XMIT_ACTIVE_MASK) != 0) {

		tx_status &= ~XEL_TSR_XMIT_ACTIVE_MASK;
		xemaclite_writel(tx_status, base_addr + XEL_BUFFER_OFFSET +
				 XEL_TSR_OFFSET);

		tx_complete = true;
	}

	/* If there was a Tx interrupt, call the Tx Handler */
	if (tx_complete != 0)
		xemaclite_tx_handler(dev);

	return IRQ_HANDLED;
}

/**********************/
/* MDIO Bus functions */
/**********************/

/**
 * xemaclite_mdio_wait - Wait for the MDIO to be ready to use
 * @lp:		Pointer to the Emaclite device private data
 *
 * This function waits till the device is ready to accept a new MDIO
 * request.
 *
 * Return:	0 for success or ETIMEDOUT for a timeout
 */

static int xemaclite_mdio_wait(struct net_local *lp)
{
	u32 val;

	/* wait for the MDIO interface to not be busy or timeout
	 * after some time.
	 */
	return readx_poll_timeout(xemaclite_readl,
				  lp->base_addr + XEL_MDIOCTRL_OFFSET,
				  val, !(val & XEL_MDIOCTRL_MDIOSTS_MASK),
				  1000, 20000);
}

/**
 * xemaclite_mdio_read - Read from a given MII management register
 * @bus:	the mii_bus struct
 * @phy_id:	the phy address
 * @reg:	register number to read from
 *
 * This function waits till the device is ready to accept a new MDIO
 * request and then writes the phy address to the MDIO Address register
 * and reads data from MDIO Read Data register, when its available.
 *
 * Return:	Value read from the MII management register
 */
static int xemaclite_mdio_read(struct mii_bus *bus, int phy_id, int reg)
{
	struct net_local *lp = bus->priv;
	u32 ctrl_reg;
	u32 rc;

	if (xemaclite_mdio_wait(lp))
		return -ETIMEDOUT;

	/* Write the PHY address, register number and set the OP bit in the
	 * MDIO Address register. Set the Status bit in the MDIO Control
	 * register to start a MDIO read transaction.
	 */
	ctrl_reg = xemaclite_readl(lp->base_addr + XEL_MDIOCTRL_OFFSET);
	xemaclite_writel(XEL_MDIOADDR_OP_MASK |
			 ((phy_id << XEL_MDIOADDR_PHYADR_SHIFT) | reg),
			 lp->base_addr + XEL_MDIOADDR_OFFSET);
	xemaclite_writel(ctrl_reg | XEL_MDIOCTRL_MDIOSTS_MASK,
			 lp->base_addr + XEL_MDIOCTRL_OFFSET);

	if (xemaclite_mdio_wait(lp))
		return -ETIMEDOUT;

	rc = xemaclite_readl(lp->base_addr + XEL_MDIORD_OFFSET);

	dev_dbg(&lp->ndev->dev,
		"%s(phy_id=%i, reg=%x) == %x\n", __func__,
		phy_id, reg, rc);

	return rc;
}

/**
 * xemaclite_mdio_write - Write to a given MII management register
 * @bus:	the mii_bus struct
 * @phy_id:	the phy address
 * @reg:	register number to write to
 * @val:	value to write to the register number specified by reg
 *
 * This function waits till the device is ready to accept a new MDIO
 * request and then writes the val to the MDIO Write Data register.
 *
 * Return:      0 upon success or a negative error upon failure
 */
static int xemaclite_mdio_write(struct mii_bus *bus, int phy_id, int reg,
				u16 val)
{
	struct net_local *lp = bus->priv;
	u32 ctrl_reg;

	dev_dbg(&lp->ndev->dev,
		"%s(phy_id=%i, reg=%x, val=%x)\n", __func__,
		phy_id, reg, val);

	if (xemaclite_mdio_wait(lp))
		return -ETIMEDOUT;

	/* Write the PHY address, register number and clear the OP bit in the
	 * MDIO Address register and then write the value into the MDIO Write
	 * Data register. Finally, set the Status bit in the MDIO Control
	 * register to start a MDIO write transaction.
	 */
	ctrl_reg = xemaclite_readl(lp->base_addr + XEL_MDIOCTRL_OFFSET);
	xemaclite_writel(~XEL_MDIOADDR_OP_MASK &
			 ((phy_id << XEL_MDIOADDR_PHYADR_SHIFT) | reg),
			 lp->base_addr + XEL_MDIOADDR_OFFSET);
	xemaclite_writel(val, lp->base_addr + XEL_MDIOWR_OFFSET);
	xemaclite_writel(ctrl_reg | XEL_MDIOCTRL_MDIOSTS_MASK,
			 lp->base_addr + XEL_MDIOCTRL_OFFSET);

	return 0;
}

/**
 * xemaclite_mdio_setup - Register mii_bus for the Emaclite device
 * @lp:		Pointer to the Emaclite device private data
 * @dev:	Pointer to OF device structure
 *
 * This function enables MDIO bus in the Emaclite device and registers a
 * mii_bus.
 *
 * Return:	0 upon success or a negative error upon failure
 */
static int xemaclite_mdio_setup(struct net_local *lp, struct device *dev)
{
	struct mii_bus *bus;
	int rc;
	struct resource res;
	struct device_node *np = of_get_parent(lp->phy_node);
	struct device_node *npp;

	/* Don't register the MDIO bus if the phy_node or its parent node
	 * can't be found.
	 */
	if (!np) {
		dev_err(dev, "Failed to register mdio bus.\n");
		return -ENODEV;
	}
	npp = of_get_parent(np);

	of_address_to_resource(npp, 0, &res);
	if (lp->ndev->mem_start != res.start) {
		struct phy_device *phydev;
		phydev = of_phy_find_device(lp->phy_node);
		if (!phydev)
			dev_info(dev,
				 "MDIO of the phy is not registered yet\n");
		else
			put_device(&phydev->mdio.dev);
		return 0;
	}

	/* Enable the MDIO bus by asserting the enable bit in MDIO Control
	 * register.
	 */
	xemaclite_writel(XEL_MDIOCTRL_MDIOEN_MASK,
			 lp->base_addr + XEL_MDIOCTRL_OFFSET);

	bus = mdiobus_alloc();
	if (!bus) {
		dev_err(dev, "Failed to allocate mdiobus\n");
		return -ENOMEM;
	}

	snprintf(bus->id, MII_BUS_ID_SIZE, "%.8llx",
		 (unsigned long long)res.start);
	bus->priv = lp;
	bus->name = "Xilinx Emaclite MDIO";
	bus->read = xemaclite_mdio_read;
	bus->write = xemaclite_mdio_write;
	bus->parent = dev;

	rc = of_mdiobus_register(bus, np);
	if (rc) {
		dev_err(dev, "Failed to register mdio bus.\n");
		goto err_register;
	}

	lp->mii_bus = bus;

	return 0;

err_register:
	mdiobus_free(bus);
	return rc;
}

/**
 * xemaclite_adjust_link - Link state callback for the Emaclite device
 * @ndev: pointer to net_device struct
 *
 * There's nothing in the Emaclite device to be configured when the link
 * state changes. We just print the status.
 */
static void xemaclite_adjust_link(struct net_device *ndev)
{
	struct net_local *lp = netdev_priv(ndev);
	struct phy_device *phy = lp->phy_dev;
	int link_state;

	/* hash together the state values to decide if something has changed */
	link_state = phy->speed | (phy->duplex << 1) | phy->link;

	if (lp->last_link != link_state) {
		lp->last_link = link_state;
		phy_print_status(phy);
	}
}

/**
 * xemaclite_open - Open the network device
 * @dev:	Pointer to the network device
 *
 * This function sets the MAC address, requests an IRQ and enables interrupts
 * for the Emaclite device and starts the Tx queue.
 * It also connects to the phy device, if MDIO is included in Emaclite device.
 *
 * Return:	0 on success. -ENODEV, if PHY cannot be connected.
 *		Non-zero error value on failure.
 */
static int xemaclite_open(struct net_device *dev)
{
	struct net_local *lp = netdev_priv(dev);
	int retval;

	/* Just to be safe, stop the device first */
	xemaclite_disable_interrupts(lp);

	if (lp->phy_node) {
		u32 bmcr;

		lp->phy_dev = of_phy_connect(lp->ndev, lp->phy_node,
					     xemaclite_adjust_link, 0,
					     PHY_INTERFACE_MODE_MII);
		if (!lp->phy_dev) {
			dev_err(&lp->ndev->dev, "of_phy_connect() failed\n");
			return -ENODEV;
		}

		/* EmacLite doesn't support giga-bit speeds */
		phy_set_max_speed(lp->phy_dev, SPEED_100);

		/* Don't advertise 1000BASE-T Full/Half duplex speeds */
		phy_write(lp->phy_dev, MII_CTRL1000, 0);

		/* Advertise only 10 and 100mbps full/half duplex speeds */
		phy_write(lp->phy_dev, MII_ADVERTISE, ADVERTISE_ALL |
			  ADVERTISE_CSMA);

		/* Restart auto negotiation */
		bmcr = phy_read(lp->phy_dev, MII_BMCR);
		bmcr |= (BMCR_ANENABLE | BMCR_ANRESTART);
		phy_write(lp->phy_dev, MII_BMCR, bmcr);

		phy_start(lp->phy_dev);
	}

	/* Set the MAC address each time opened */
	xemaclite_update_address(lp, dev->dev_addr);

	/* Grab the IRQ */
	retval = request_irq(dev->irq, xemaclite_interrupt, 0, dev->name, dev);
	if (retval) {
		dev_err(&lp->ndev->dev, "Could not allocate interrupt %d\n",
			dev->irq);
		if (lp->phy_dev)
			phy_disconnect(lp->phy_dev);
		lp->phy_dev = NULL;

		return retval;
	}

	/* Enable Interrupts */
	xemaclite_enable_interrupts(lp);

	/* We're ready to go */
	netif_start_queue(dev);

	return 0;
}

/**
 * xemaclite_close - Close the network device
 * @dev:	Pointer to the network device
 *
 * This function stops the Tx queue, disables interrupts and frees the IRQ for
 * the Emaclite device.
 * It also disconnects the phy device associated with the Emaclite device.
 *
 * Return:	0, always.
 */
static int xemaclite_close(struct net_device *dev)
{
	struct net_local *lp = netdev_priv(dev);

	netif_stop_queue(dev);
	xemaclite_disable_interrupts(lp);
	free_irq(dev->irq, dev);

	if (lp->phy_dev)
		phy_disconnect(lp->phy_dev);
	lp->phy_dev = NULL;

	return 0;
}

/**
 * xemaclite_send - Transmit a frame
 * @orig_skb:	Pointer to the socket buffer to be transmitted
 * @dev:	Pointer to the network device
 *
 * This function checks if the Tx buffer of the Emaclite device is free to send
 * data. If so, it fills the Tx buffer with data from socket buffer data,
 * updates the stats and frees the socket buffer. The Tx completion is signaled
 * by an interrupt. If the Tx buffer isn't free, then the socket buffer is
 * deferred and the Tx queue is stopped so that the deferred socket buffer can
 * be transmitted when the Emaclite device is free to transmit data.
 *
 * Return:	NETDEV_TX_OK, always.
 */
static netdev_tx_t
xemaclite_send(struct sk_buff *orig_skb, struct net_device *dev)
{
	struct net_local *lp = netdev_priv(dev);
	struct sk_buff *new_skb;
	unsigned int len;
	unsigned long flags;

	len = orig_skb->len;

	new_skb = orig_skb;

	spin_lock_irqsave(&lp->reset_lock, flags);
	if (xemaclite_send_data(lp, (u8 *)new_skb->data, len) != 0) {
		/* If the Emaclite Tx buffer is busy, stop the Tx queue and
		 * defer the skb for transmission during the ISR, after the
		 * current transmission is complete
		 */
		netif_stop_queue(dev);
		lp->deferred_skb = new_skb;
		/* Take the time stamp now, since we can't do this in an ISR. */
		skb_tx_timestamp(new_skb);
		spin_unlock_irqrestore(&lp->reset_lock, flags);
		return NETDEV_TX_OK;
	}
	spin_unlock_irqrestore(&lp->reset_lock, flags);

	skb_tx_timestamp(new_skb);

	dev->stats.tx_bytes += len;
	dev_consume_skb_any(new_skb);

	return NETDEV_TX_OK;
}

/**
 * get_bool - Get a parameter from the OF device
 * @ofdev:	Pointer to OF device structure
 * @s:		Property to be retrieved
 *
 * This function looks for a property in the device node and returns the value
 * of the property if its found or 0 if the property is not found.
 *
 * Return:	Value of the parameter if the parameter is found, or 0 otherwise
 */
static bool get_bool(struct platform_device *ofdev, const char *s)
{
	u32 *p = (u32 *)of_get_property(ofdev->dev.of_node, s, NULL);

	if (!p) {
		dev_warn(&ofdev->dev, "Parameter %s not found, defaulting to false\n", s);
		return false;
	}

	return (bool)*p;
}

/**
 * xemaclite_ethtools_get_drvinfo - Get various Axi Emac Lite driver info
 * @ndev:       Pointer to net_device structure
 * @ed:         Pointer to ethtool_drvinfo structure
 *
 * This implements ethtool command for getting the driver information.
 * Issue "ethtool -i ethX" under linux prompt to execute this function.
 */
static void xemaclite_ethtools_get_drvinfo(struct net_device *ndev,
					   struct ethtool_drvinfo *ed)
{
	strlcpy(ed->driver, DRIVER_NAME, sizeof(ed->driver));
}

static const struct ethtool_ops xemaclite_ethtool_ops = {
	.get_drvinfo    = xemaclite_ethtools_get_drvinfo,
	.get_link       = ethtool_op_get_link,
	.get_link_ksettings = phy_ethtool_get_link_ksettings,
	.set_link_ksettings = phy_ethtool_set_link_ksettings,
};

static const struct net_device_ops xemaclite_netdev_ops;

/**
 * xemaclite_of_probe - Probe method for the Emaclite device.
 * @ofdev:	Pointer to OF device structure
 *
 * This function probes for the Emaclite device in the device tree.
 * It initializes the driver data structure and the hardware, sets the MAC
 * address and registers the network device.
 * It also registers a mii_bus for the Emaclite device, if MDIO is included
 * in the device.
 *
 * Return:	0, if the driver is bound to the Emaclite device, or
 *		a negative error if there is failure.
 */
static int xemaclite_of_probe(struct platform_device *ofdev)
{
	struct resource *res;
	struct net_device *ndev = NULL;
	struct net_local *lp = NULL;
	struct device *dev = &ofdev->dev;
	const void *mac_address;

	int rc = 0;

	dev_info(dev, "Device Tree Probing\n");

	/* Create an ethernet device instance */
	ndev = alloc_etherdev(sizeof(struct net_local));
	if (!ndev)
		return -ENOMEM;

	dev_set_drvdata(dev, ndev);
	SET_NETDEV_DEV(ndev, &ofdev->dev);

	lp = netdev_priv(ndev);
	lp->ndev = ndev;

	/* Get IRQ for the device */
	res = platform_get_resource(ofdev, IORESOURCE_IRQ, 0);
	if (!res) {
		dev_err(dev, "no IRQ found\n");
		rc = -ENXIO;
		goto error;
	}

	ndev->irq = res->start;

	res = platform_get_resource(ofdev, IORESOURCE_MEM, 0);
	lp->base_addr = devm_ioremap_resource(&ofdev->dev, res);
	if (IS_ERR(lp->base_addr)) {
		rc = PTR_ERR(lp->base_addr);
		goto error;
	}

	ndev->mem_start = res->start;
	ndev->mem_end = res->end;

	spin_lock_init(&lp->reset_lock);
	lp->next_tx_buf_to_use = 0x0;
	lp->next_rx_buf_to_use = 0x0;
	lp->tx_ping_pong = get_bool(ofdev, "xlnx,tx-ping-pong");
	lp->rx_ping_pong = get_bool(ofdev, "xlnx,rx-ping-pong");
	mac_address = of_get_mac_address(ofdev->dev.of_node);

	if (!IS_ERR(mac_address)) {
		/* Set the MAC address. */
		ether_addr_copy(ndev->dev_addr, mac_address);
	} else {
		dev_warn(dev, "No MAC address found, using random\n");
		eth_hw_addr_random(ndev);
	}

	/* Clear the Tx CSR's in case this is a restart */
	xemaclite_writel(0, lp->base_addr + XEL_TSR_OFFSET);
	xemaclite_writel(0, lp->base_addr + XEL_BUFFER_OFFSET + XEL_TSR_OFFSET);

	/* Set the MAC address in the EmacLite device */
	xemaclite_update_address(lp, ndev->dev_addr);

	lp->phy_node = of_parse_phandle(ofdev->dev.of_node, "phy-handle", 0);
	xemaclite_mdio_setup(lp, &ofdev->dev);

	dev_info(dev, "MAC address is now %pM\n", ndev->dev_addr);

	ndev->netdev_ops = &xemaclite_netdev_ops;
	ndev->ethtool_ops = &xemaclite_ethtool_ops;
	ndev->flags &= ~IFF_MULTICAST;
	ndev->watchdog_timeo = TX_TIMEOUT;

	/* Finally, register the device */
	rc = register_netdev(ndev);
	if (rc) {
		dev_err(dev,
			"Cannot register network device, aborting\n");
		goto put_node;
	}

	dev_info(dev,
		 "Xilinx EmacLite at 0x%08X mapped to 0x%p, irq=%d\n",
		 (unsigned int __force)ndev->mem_start, lp->base_addr, ndev->irq);
	return 0;

put_node:
	of_node_put(lp->phy_node);
error:
	free_netdev(ndev);
	return rc;
}

/**
 * xemaclite_of_remove - Unbind the driver from the Emaclite device.
 * @of_dev:	Pointer to OF device structure
 *
 * This function is called if a device is physically removed from the system or
 * if the driver module is being unloaded. It frees any resources allocated to
 * the device.
 *
 * Return:	0, always.
 */
static int xemaclite_of_remove(struct platform_device *of_dev)
{
	struct net_device *ndev = platform_get_drvdata(of_dev);

	struct net_local *lp = netdev_priv(ndev);

	/* Un-register the mii_bus, if configured */
	if (lp->mii_bus) {
		mdiobus_unregister(lp->mii_bus);
		mdiobus_free(lp->mii_bus);
		lp->mii_bus = NULL;
	}

	unregister_netdev(ndev);

	of_node_put(lp->phy_node);
	lp->phy_node = NULL;

	free_netdev(ndev);

	return 0;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void
xemaclite_poll_controller(struct net_device *ndev)
{
	disable_irq(ndev->irq);
	xemaclite_interrupt(ndev->irq, ndev);
	enable_irq(ndev->irq);
}
#endif

/* Ioctl MII Interface */
static int xemaclite_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
{
	if (!dev->phydev || !netif_running(dev))
		return -EINVAL;

	switch (cmd) {
	case SIOCGMIIPHY:
	case SIOCGMIIREG:
	case SIOCSMIIREG:
		return phy_mii_ioctl(dev->phydev, rq, cmd);
	default:
		return -EOPNOTSUPP;
	}
}

static const struct net_device_ops xemaclite_netdev_ops = {
	.ndo_open		= xemaclite_open,
	.ndo_stop		= xemaclite_close,
	.ndo_start_xmit		= xemaclite_send,
	.ndo_set_mac_address	= xemaclite_set_mac_address,
	.ndo_tx_timeout		= xemaclite_tx_timeout,
	.ndo_do_ioctl		= xemaclite_ioctl,
#ifdef CONFIG_NET_POLL_CONTROLLER
	.ndo_poll_controller = xemaclite_poll_controller,
#endif
};

/* Match table for OF platform binding */
static const struct of_device_id xemaclite_of_match[] = {
	{ .compatible = "xlnx,opb-ethernetlite-1.01.a", },
	{ .compatible = "xlnx,opb-ethernetlite-1.01.b", },
	{ .compatible = "xlnx,xps-ethernetlite-1.00.a", },
	{ .compatible = "xlnx,xps-ethernetlite-2.00.a", },
	{ .compatible = "xlnx,xps-ethernetlite-2.01.a", },
	{ .compatible = "xlnx,xps-ethernetlite-3.00.a", },
	{ /* end of list */ },
};
MODULE_DEVICE_TABLE(of, xemaclite_of_match);

static struct platform_driver xemaclite_of_driver = {
	.driver = {
		.name = DRIVER_NAME,
		.of_match_table = xemaclite_of_match,
	},
	.probe		= xemaclite_of_probe,
	.remove		= xemaclite_of_remove,
};

module_platform_driver(xemaclite_of_driver);

MODULE_AUTHOR("Xilinx, Inc.");
MODULE_DESCRIPTION("Xilinx Ethernet MAC Lite driver");
MODULE_LICENSE("GPL");