summaryrefslogtreecommitdiff
path: root/drivers/net/ethernet/allwinner/sun4i-emac.c
blob: 50b853a79d7787c73d0ea8d0ac1f1e0853ac2adf (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
/*
 * Allwinner EMAC Fast Ethernet driver for Linux.
 *
 * Copyright 2012-2013 Stefan Roese <sr@denx.de>
 * Copyright 2013 Maxime Ripard <maxime.ripard@free-electrons.com>
 *
 * Based on the Linux driver provided by Allwinner:
 * Copyright (C) 1997  Sten Wang
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/clk.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/gpio.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/mii.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_mdio.h>
#include <linux/of_net.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/phy.h>

#include "sun4i-emac.h"

#define DRV_NAME		"sun4i-emac"
#define DRV_VERSION		"1.02"

#define EMAC_MAX_FRAME_LEN	0x0600

/* Transmit timeout, default 5 seconds. */
static int watchdog = 5000;
module_param(watchdog, int, 0400);
MODULE_PARM_DESC(watchdog, "transmit timeout in milliseconds");

/* EMAC register address locking.
 *
 * The EMAC uses an address register to control where data written
 * to the data register goes. This means that the address register
 * must be preserved over interrupts or similar calls.
 *
 * During interrupt and other critical calls, a spinlock is used to
 * protect the system, but the calls themselves save the address
 * in the address register in case they are interrupting another
 * access to the device.
 *
 * For general accesses a lock is provided so that calls which are
 * allowed to sleep are serialised so that the address register does
 * not need to be saved. This lock also serves to serialise access
 * to the EEPROM and PHY access registers which are shared between
 * these two devices.
 */

/* The driver supports the original EMACE, and now the two newer
 * devices, EMACA and EMACB.
 */

struct emac_board_info {
	struct clk		*clk;
	struct device		*dev;
	struct platform_device	*pdev;
	spinlock_t		lock;
	void __iomem		*membase;
	u32			msg_enable;
	struct net_device	*ndev;
	struct sk_buff		*skb_last;
	u16			tx_fifo_stat;

	int			emacrx_completed_flag;

	struct phy_device	*phy_dev;
	struct device_node	*phy_node;
	unsigned int		link;
	unsigned int		speed;
	unsigned int		duplex;

	phy_interface_t		phy_interface;
};

static void emac_update_speed(struct net_device *dev)
{
	struct emac_board_info *db = netdev_priv(dev);
	unsigned int reg_val;

	/* set EMAC SPEED, depend on PHY  */
	reg_val = readl(db->membase + EMAC_MAC_SUPP_REG);
	reg_val &= ~(0x1 << 8);
	if (db->speed == SPEED_100)
		reg_val |= 1 << 8;
	writel(reg_val, db->membase + EMAC_MAC_SUPP_REG);
}

static void emac_update_duplex(struct net_device *dev)
{
	struct emac_board_info *db = netdev_priv(dev);
	unsigned int reg_val;

	/* set duplex depend on phy */
	reg_val = readl(db->membase + EMAC_MAC_CTL1_REG);
	reg_val &= ~EMAC_MAC_CTL1_DUPLEX_EN;
	if (db->duplex)
		reg_val |= EMAC_MAC_CTL1_DUPLEX_EN;
	writel(reg_val, db->membase + EMAC_MAC_CTL1_REG);
}

static void emac_handle_link_change(struct net_device *dev)
{
	struct emac_board_info *db = netdev_priv(dev);
	struct phy_device *phydev = db->phy_dev;
	unsigned long flags;
	int status_change = 0;

	if (phydev->link) {
		if (db->speed != phydev->speed) {
			spin_lock_irqsave(&db->lock, flags);
			db->speed = phydev->speed;
			emac_update_speed(dev);
			spin_unlock_irqrestore(&db->lock, flags);
			status_change = 1;
		}

		if (db->duplex != phydev->duplex) {
			spin_lock_irqsave(&db->lock, flags);
			db->duplex = phydev->duplex;
			emac_update_duplex(dev);
			spin_unlock_irqrestore(&db->lock, flags);
			status_change = 1;
		}
	}

	if (phydev->link != db->link) {
		if (!phydev->link) {
			db->speed = 0;
			db->duplex = -1;
		}
		db->link = phydev->link;

		status_change = 1;
	}

	if (status_change)
		phy_print_status(phydev);
}

static int emac_mdio_probe(struct net_device *dev)
{
	struct emac_board_info *db = netdev_priv(dev);

	/* to-do: PHY interrupts are currently not supported */

	/* attach the mac to the phy */
	db->phy_dev = of_phy_connect(db->ndev, db->phy_node,
				     &emac_handle_link_change, 0,
				     db->phy_interface);
	if (!db->phy_dev) {
		netdev_err(db->ndev, "could not find the PHY\n");
		return -ENODEV;
	}

	/* mask with MAC supported features */
	db->phy_dev->supported &= PHY_BASIC_FEATURES;
	db->phy_dev->advertising = db->phy_dev->supported;

	db->link = 0;
	db->speed = 0;
	db->duplex = -1;

	return 0;
}

static void emac_mdio_remove(struct net_device *dev)
{
	struct emac_board_info *db = netdev_priv(dev);

	phy_disconnect(db->phy_dev);
	db->phy_dev = NULL;
}

static void emac_reset(struct emac_board_info *db)
{
	dev_dbg(db->dev, "resetting device\n");

	/* RESET device */
	writel(0, db->membase + EMAC_CTL_REG);
	udelay(200);
	writel(EMAC_CTL_RESET, db->membase + EMAC_CTL_REG);
	udelay(200);
}

static void emac_outblk_32bit(void __iomem *reg, void *data, int count)
{
	writesl(reg, data, round_up(count, 4) / 4);
}

static void emac_inblk_32bit(void __iomem *reg, void *data, int count)
{
	readsl(reg, data, round_up(count, 4) / 4);
}

static int emac_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
{
	struct emac_board_info *dm = netdev_priv(dev);
	struct phy_device *phydev = dm->phy_dev;

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

	if (!phydev)
		return -ENODEV;

	return phy_mii_ioctl(phydev, rq, cmd);
}

/* ethtool ops */
static void emac_get_drvinfo(struct net_device *dev,
			      struct ethtool_drvinfo *info)
{
	strlcpy(info->driver, DRV_NAME, sizeof(DRV_NAME));
	strlcpy(info->version, DRV_VERSION, sizeof(DRV_VERSION));
	strlcpy(info->bus_info, dev_name(&dev->dev), sizeof(info->bus_info));
}

static int emac_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
	struct emac_board_info *dm = netdev_priv(dev);
	struct phy_device *phydev = dm->phy_dev;

	if (!phydev)
		return -ENODEV;

	return phy_ethtool_gset(phydev, cmd);
}

static int emac_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
	struct emac_board_info *dm = netdev_priv(dev);
	struct phy_device *phydev = dm->phy_dev;

	if (!phydev)
		return -ENODEV;

	return phy_ethtool_sset(phydev, cmd);
}

static const struct ethtool_ops emac_ethtool_ops = {
	.get_drvinfo	= emac_get_drvinfo,
	.get_settings	= emac_get_settings,
	.set_settings	= emac_set_settings,
	.get_link	= ethtool_op_get_link,
};

static unsigned int emac_setup(struct net_device *ndev)
{
	struct emac_board_info *db = netdev_priv(ndev);
	unsigned int reg_val;

	/* set up TX */
	reg_val = readl(db->membase + EMAC_TX_MODE_REG);

	writel(reg_val | EMAC_TX_MODE_ABORTED_FRAME_EN,
		db->membase + EMAC_TX_MODE_REG);

	/* set up RX */
	reg_val = readl(db->membase + EMAC_RX_CTL_REG);

	writel(reg_val | EMAC_RX_CTL_PASS_LEN_OOR_EN |
		EMAC_RX_CTL_ACCEPT_UNICAST_EN | EMAC_RX_CTL_DA_FILTER_EN |
		EMAC_RX_CTL_ACCEPT_MULTICAST_EN |
		EMAC_RX_CTL_ACCEPT_BROADCAST_EN,
		db->membase + EMAC_RX_CTL_REG);

	/* set MAC */
	/* set MAC CTL0 */
	reg_val = readl(db->membase + EMAC_MAC_CTL0_REG);
	writel(reg_val | EMAC_MAC_CTL0_RX_FLOW_CTL_EN |
		EMAC_MAC_CTL0_TX_FLOW_CTL_EN,
		db->membase + EMAC_MAC_CTL0_REG);

	/* set MAC CTL1 */
	reg_val = readl(db->membase + EMAC_MAC_CTL1_REG);
	reg_val |= EMAC_MAC_CTL1_LEN_CHECK_EN;
	reg_val |= EMAC_MAC_CTL1_CRC_EN;
	reg_val |= EMAC_MAC_CTL1_PAD_EN;
	writel(reg_val, db->membase + EMAC_MAC_CTL1_REG);

	/* set up IPGT */
	writel(EMAC_MAC_IPGT_FULL_DUPLEX, db->membase + EMAC_MAC_IPGT_REG);

	/* set up IPGR */
	writel((EMAC_MAC_IPGR_IPG1 << 8) | EMAC_MAC_IPGR_IPG2,
		db->membase + EMAC_MAC_IPGR_REG);

	/* set up Collison window */
	writel((EMAC_MAC_CLRT_COLLISION_WINDOW << 8) | EMAC_MAC_CLRT_RM,
		db->membase + EMAC_MAC_CLRT_REG);

	/* set up Max Frame Length */
	writel(EMAC_MAX_FRAME_LEN,
		db->membase + EMAC_MAC_MAXF_REG);

	return 0;
}

static unsigned int emac_powerup(struct net_device *ndev)
{
	struct emac_board_info *db = netdev_priv(ndev);
	unsigned int reg_val;

	/* initial EMAC */
	/* flush RX FIFO */
	reg_val = readl(db->membase + EMAC_RX_CTL_REG);
	reg_val |= 0x8;
	writel(reg_val, db->membase + EMAC_RX_CTL_REG);
	udelay(1);

	/* initial MAC */
	/* soft reset MAC */
	reg_val = readl(db->membase + EMAC_MAC_CTL0_REG);
	reg_val &= ~EMAC_MAC_CTL0_SOFT_RESET;
	writel(reg_val, db->membase + EMAC_MAC_CTL0_REG);

	/* set MII clock */
	reg_val = readl(db->membase + EMAC_MAC_MCFG_REG);
	reg_val &= (~(0xf << 2));
	reg_val |= (0xD << 2);
	writel(reg_val, db->membase + EMAC_MAC_MCFG_REG);

	/* clear RX counter */
	writel(0x0, db->membase + EMAC_RX_FBC_REG);

	/* disable all interrupt and clear interrupt status */
	writel(0, db->membase + EMAC_INT_CTL_REG);
	reg_val = readl(db->membase + EMAC_INT_STA_REG);
	writel(reg_val, db->membase + EMAC_INT_STA_REG);

	udelay(1);

	/* set up EMAC */
	emac_setup(ndev);

	/* set mac_address to chip */
	writel(ndev->dev_addr[0] << 16 | ndev->dev_addr[1] << 8 | ndev->
	       dev_addr[2], db->membase + EMAC_MAC_A1_REG);
	writel(ndev->dev_addr[3] << 16 | ndev->dev_addr[4] << 8 | ndev->
	       dev_addr[5], db->membase + EMAC_MAC_A0_REG);

	mdelay(1);

	return 0;
}

static int emac_set_mac_address(struct net_device *dev, void *p)
{
	struct sockaddr *addr = p;
	struct emac_board_info *db = netdev_priv(dev);

	if (netif_running(dev))
		return -EBUSY;

	memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);

	writel(dev->dev_addr[0] << 16 | dev->dev_addr[1] << 8 | dev->
	       dev_addr[2], db->membase + EMAC_MAC_A1_REG);
	writel(dev->dev_addr[3] << 16 | dev->dev_addr[4] << 8 | dev->
	       dev_addr[5], db->membase + EMAC_MAC_A0_REG);

	return 0;
}

/* Initialize emac board */
static void emac_init_device(struct net_device *dev)
{
	struct emac_board_info *db = netdev_priv(dev);
	unsigned long flags;
	unsigned int reg_val;

	spin_lock_irqsave(&db->lock, flags);

	emac_update_speed(dev);
	emac_update_duplex(dev);

	/* enable RX/TX */
	reg_val = readl(db->membase + EMAC_CTL_REG);
	writel(reg_val | EMAC_CTL_RESET | EMAC_CTL_TX_EN | EMAC_CTL_RX_EN,
		db->membase + EMAC_CTL_REG);

	/* enable RX/TX0/RX Hlevel interrup */
	reg_val = readl(db->membase + EMAC_INT_CTL_REG);
	reg_val |= (0xf << 0) | (0x01 << 8);
	writel(reg_val, db->membase + EMAC_INT_CTL_REG);

	spin_unlock_irqrestore(&db->lock, flags);
}

/* Our watchdog timed out. Called by the networking layer */
static void emac_timeout(struct net_device *dev)
{
	struct emac_board_info *db = netdev_priv(dev);
	unsigned long flags;

	if (netif_msg_timer(db))
		dev_err(db->dev, "tx time out.\n");

	/* Save previous register address */
	spin_lock_irqsave(&db->lock, flags);

	netif_stop_queue(dev);
	emac_reset(db);
	emac_init_device(dev);
	/* We can accept TX packets again */
	dev->trans_start = jiffies;
	netif_wake_queue(dev);

	/* Restore previous register address */
	spin_unlock_irqrestore(&db->lock, flags);
}

/* Hardware start transmission.
 * Send a packet to media from the upper layer.
 */
static int emac_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct emac_board_info *db = netdev_priv(dev);
	unsigned long channel;
	unsigned long flags;

	channel = db->tx_fifo_stat & 3;
	if (channel == 3)
		return 1;

	channel = (channel == 1 ? 1 : 0);

	spin_lock_irqsave(&db->lock, flags);

	writel(channel, db->membase + EMAC_TX_INS_REG);

	emac_outblk_32bit(db->membase + EMAC_TX_IO_DATA_REG,
			skb->data, skb->len);
	dev->stats.tx_bytes += skb->len;

	db->tx_fifo_stat |= 1 << channel;
	/* TX control: First packet immediately send, second packet queue */
	if (channel == 0) {
		/* set TX len */
		writel(skb->len, db->membase + EMAC_TX_PL0_REG);
		/* start translate from fifo to phy */
		writel(readl(db->membase + EMAC_TX_CTL0_REG) | 1,
		       db->membase + EMAC_TX_CTL0_REG);

		/* save the time stamp */
		dev->trans_start = jiffies;
	} else if (channel == 1) {
		/* set TX len */
		writel(skb->len, db->membase + EMAC_TX_PL1_REG);
		/* start translate from fifo to phy */
		writel(readl(db->membase + EMAC_TX_CTL1_REG) | 1,
		       db->membase + EMAC_TX_CTL1_REG);

		/* save the time stamp */
		dev->trans_start = jiffies;
	}

	if ((db->tx_fifo_stat & 3) == 3) {
		/* Second packet */
		netif_stop_queue(dev);
	}

	spin_unlock_irqrestore(&db->lock, flags);

	/* free this SKB */
	dev_kfree_skb(skb);

	return NETDEV_TX_OK;
}

/* EMAC interrupt handler
 * receive the packet to upper layer, free the transmitted packet
 */
static void emac_tx_done(struct net_device *dev, struct emac_board_info *db,
			  unsigned int tx_status)
{
	/* One packet sent complete */
	db->tx_fifo_stat &= ~(tx_status & 3);
	if (3 == (tx_status & 3))
		dev->stats.tx_packets += 2;
	else
		dev->stats.tx_packets++;

	if (netif_msg_tx_done(db))
		dev_dbg(db->dev, "tx done, NSR %02x\n", tx_status);

	netif_wake_queue(dev);
}

/* Received a packet and pass to upper layer
 */
static void emac_rx(struct net_device *dev)
{
	struct emac_board_info *db = netdev_priv(dev);
	struct sk_buff *skb;
	u8 *rdptr;
	bool good_packet;
	static int rxlen_last;
	unsigned int reg_val;
	u32 rxhdr, rxstatus, rxcount, rxlen;

	/* Check packet ready or not */
	while (1) {
		/* race warning: the first packet might arrive with
		 * the interrupts disabled, but the second will fix
		 * it
		 */
		rxcount = readl(db->membase + EMAC_RX_FBC_REG);

		if (netif_msg_rx_status(db))
			dev_dbg(db->dev, "RXCount: %x\n", rxcount);

		if ((db->skb_last != NULL) && (rxlen_last > 0)) {
			dev->stats.rx_bytes += rxlen_last;

			/* Pass to upper layer */
			db->skb_last->protocol = eth_type_trans(db->skb_last,
								dev);
			netif_rx(db->skb_last);
			dev->stats.rx_packets++;
			db->skb_last = NULL;
			rxlen_last = 0;

			reg_val = readl(db->membase + EMAC_RX_CTL_REG);
			reg_val &= ~EMAC_RX_CTL_DMA_EN;
			writel(reg_val, db->membase + EMAC_RX_CTL_REG);
		}

		if (!rxcount) {
			db->emacrx_completed_flag = 1;
			reg_val = readl(db->membase + EMAC_INT_CTL_REG);
			reg_val |= (0xf << 0) | (0x01 << 8);
			writel(reg_val, db->membase + EMAC_INT_CTL_REG);

			/* had one stuck? */
			rxcount = readl(db->membase + EMAC_RX_FBC_REG);
			if (!rxcount)
				return;
		}

		reg_val = readl(db->membase + EMAC_RX_IO_DATA_REG);
		if (netif_msg_rx_status(db))
			dev_dbg(db->dev, "receive header: %x\n", reg_val);
		if (reg_val != EMAC_UNDOCUMENTED_MAGIC) {
			/* disable RX */
			reg_val = readl(db->membase + EMAC_CTL_REG);
			writel(reg_val & ~EMAC_CTL_RX_EN,
			       db->membase + EMAC_CTL_REG);

			/* Flush RX FIFO */
			reg_val = readl(db->membase + EMAC_RX_CTL_REG);
			writel(reg_val | (1 << 3),
			       db->membase + EMAC_RX_CTL_REG);

			do {
				reg_val = readl(db->membase + EMAC_RX_CTL_REG);
			} while (reg_val & (1 << 3));

			/* enable RX */
			reg_val = readl(db->membase + EMAC_CTL_REG);
			writel(reg_val | EMAC_CTL_RX_EN,
			       db->membase + EMAC_CTL_REG);
			reg_val = readl(db->membase + EMAC_INT_CTL_REG);
			reg_val |= (0xf << 0) | (0x01 << 8);
			writel(reg_val, db->membase + EMAC_INT_CTL_REG);

			db->emacrx_completed_flag = 1;

			return;
		}

		/* A packet ready now  & Get status/length */
		good_packet = true;

		emac_inblk_32bit(db->membase + EMAC_RX_IO_DATA_REG,
				&rxhdr, sizeof(rxhdr));

		if (netif_msg_rx_status(db))
			dev_dbg(db->dev, "rxhdr: %x\n", *((int *)(&rxhdr)));

		rxlen = EMAC_RX_IO_DATA_LEN(rxhdr);
		rxstatus = EMAC_RX_IO_DATA_STATUS(rxhdr);

		if (netif_msg_rx_status(db))
			dev_dbg(db->dev, "RX: status %02x, length %04x\n",
				rxstatus, rxlen);

		/* Packet Status check */
		if (rxlen < 0x40) {
			good_packet = false;
			if (netif_msg_rx_err(db))
				dev_dbg(db->dev, "RX: Bad Packet (runt)\n");
		}

		if (unlikely(!(rxstatus & EMAC_RX_IO_DATA_STATUS_OK))) {
			good_packet = false;

			if (rxstatus & EMAC_RX_IO_DATA_STATUS_CRC_ERR) {
				if (netif_msg_rx_err(db))
					dev_dbg(db->dev, "crc error\n");
				dev->stats.rx_crc_errors++;
			}

			if (rxstatus & EMAC_RX_IO_DATA_STATUS_LEN_ERR) {
				if (netif_msg_rx_err(db))
					dev_dbg(db->dev, "length error\n");
				dev->stats.rx_length_errors++;
			}
		}

		/* Move data from EMAC */
		skb = dev_alloc_skb(rxlen + 4);
		if (good_packet && skb) {
			skb_reserve(skb, 2);
			rdptr = (u8 *) skb_put(skb, rxlen - 4);

			/* Read received packet from RX SRAM */
			if (netif_msg_rx_status(db))
				dev_dbg(db->dev, "RxLen %x\n", rxlen);

			emac_inblk_32bit(db->membase + EMAC_RX_IO_DATA_REG,
					rdptr, rxlen);
			dev->stats.rx_bytes += rxlen;

			/* Pass to upper layer */
			skb->protocol = eth_type_trans(skb, dev);
			netif_rx(skb);
			dev->stats.rx_packets++;
		}
	}
}

static irqreturn_t emac_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = dev_id;
	struct emac_board_info *db = netdev_priv(dev);
	int int_status;
	unsigned long flags;
	unsigned int reg_val;

	/* A real interrupt coming */

	/* holders of db->lock must always block IRQs */
	spin_lock_irqsave(&db->lock, flags);

	/* Disable all interrupts */
	writel(0, db->membase + EMAC_INT_CTL_REG);

	/* Got EMAC interrupt status */
	/* Got ISR */
	int_status = readl(db->membase + EMAC_INT_STA_REG);
	/* Clear ISR status */
	writel(int_status, db->membase + EMAC_INT_STA_REG);

	if (netif_msg_intr(db))
		dev_dbg(db->dev, "emac interrupt %02x\n", int_status);

	/* Received the coming packet */
	if ((int_status & 0x100) && (db->emacrx_completed_flag == 1)) {
		/* carrier lost */
		db->emacrx_completed_flag = 0;
		emac_rx(dev);
	}

	/* Transmit Interrupt check */
	if (int_status & (0x01 | 0x02))
		emac_tx_done(dev, db, int_status);

	if (int_status & (0x04 | 0x08))
		netdev_info(dev, " ab : %x\n", int_status);

	/* Re-enable interrupt mask */
	if (db->emacrx_completed_flag == 1) {
		reg_val = readl(db->membase + EMAC_INT_CTL_REG);
		reg_val |= (0xf << 0) | (0x01 << 8);
		writel(reg_val, db->membase + EMAC_INT_CTL_REG);
	}
	spin_unlock_irqrestore(&db->lock, flags);

	return IRQ_HANDLED;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
/*
 * Used by netconsole
 */
static void emac_poll_controller(struct net_device *dev)
{
	disable_irq(dev->irq);
	emac_interrupt(dev->irq, dev);
	enable_irq(dev->irq);
}
#endif

/*  Open the interface.
 *  The interface is opened whenever "ifconfig" actives it.
 */
static int emac_open(struct net_device *dev)
{
	struct emac_board_info *db = netdev_priv(dev);
	int ret;

	if (netif_msg_ifup(db))
		dev_dbg(db->dev, "enabling %s\n", dev->name);

	if (devm_request_irq(db->dev, dev->irq, &emac_interrupt,
			     0, dev->name, dev))
		return -EAGAIN;

	/* Initialize EMAC board */
	emac_reset(db);
	emac_init_device(dev);

	ret = emac_mdio_probe(dev);
	if (ret < 0) {
		netdev_err(dev, "cannot probe MDIO bus\n");
		return ret;
	}

	phy_start(db->phy_dev);
	netif_start_queue(dev);

	return 0;
}

static void emac_shutdown(struct net_device *dev)
{
	unsigned int reg_val;
	struct emac_board_info *db = netdev_priv(dev);

	/* Disable all interrupt */
	writel(0, db->membase + EMAC_INT_CTL_REG);

	/* clear interupt status */
	reg_val = readl(db->membase + EMAC_INT_STA_REG);
	writel(reg_val, db->membase + EMAC_INT_STA_REG);

	/* Disable RX/TX */
	reg_val = readl(db->membase + EMAC_CTL_REG);
	reg_val &= ~(EMAC_CTL_TX_EN | EMAC_CTL_RX_EN | EMAC_CTL_RESET);
	writel(reg_val, db->membase + EMAC_CTL_REG);
}

/* Stop the interface.
 * The interface is stopped when it is brought.
 */
static int emac_stop(struct net_device *ndev)
{
	struct emac_board_info *db = netdev_priv(ndev);

	if (netif_msg_ifdown(db))
		dev_dbg(db->dev, "shutting down %s\n", ndev->name);

	netif_stop_queue(ndev);
	netif_carrier_off(ndev);

	phy_stop(db->phy_dev);

	emac_mdio_remove(ndev);

	emac_shutdown(ndev);

	return 0;
}

static const struct net_device_ops emac_netdev_ops = {
	.ndo_open		= emac_open,
	.ndo_stop		= emac_stop,
	.ndo_start_xmit		= emac_start_xmit,
	.ndo_tx_timeout		= emac_timeout,
	.ndo_do_ioctl		= emac_ioctl,
	.ndo_change_mtu		= eth_change_mtu,
	.ndo_validate_addr	= eth_validate_addr,
	.ndo_set_mac_address	= emac_set_mac_address,
#ifdef CONFIG_NET_POLL_CONTROLLER
	.ndo_poll_controller	= emac_poll_controller,
#endif
};

/* Search EMAC board, allocate space and register it
 */
static int emac_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct emac_board_info *db;
	struct net_device *ndev;
	int ret = 0;
	const char *mac_addr;

	ndev = alloc_etherdev(sizeof(struct emac_board_info));
	if (!ndev) {
		dev_err(&pdev->dev, "could not allocate device.\n");
		return -ENOMEM;
	}

	SET_NETDEV_DEV(ndev, &pdev->dev);

	db = netdev_priv(ndev);
	memset(db, 0, sizeof(*db));

	db->dev = &pdev->dev;
	db->ndev = ndev;
	db->pdev = pdev;

	spin_lock_init(&db->lock);

	db->membase = of_iomap(np, 0);
	if (!db->membase) {
		dev_err(&pdev->dev, "failed to remap registers\n");
		ret = -ENOMEM;
		goto out;
	}

	/* fill in parameters for net-dev structure */
	ndev->base_addr = (unsigned long)db->membase;
	ndev->irq = irq_of_parse_and_map(np, 0);
	if (ndev->irq == -ENXIO) {
		netdev_err(ndev, "No irq resource\n");
		ret = ndev->irq;
		goto out;
	}

	db->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(db->clk))
		goto out;

	clk_prepare_enable(db->clk);

	db->phy_node = of_parse_phandle(np, "phy", 0);
	if (!db->phy_node) {
		dev_err(&pdev->dev, "no associated PHY\n");
		ret = -ENODEV;
		goto out;
	}

	/* Read MAC-address from DT */
	mac_addr = of_get_mac_address(np);
	if (mac_addr)
		memcpy(ndev->dev_addr, mac_addr, ETH_ALEN);

	/* Check if the MAC address is valid, if not get a random one */
	if (!is_valid_ether_addr(ndev->dev_addr)) {
		eth_hw_addr_random(ndev);
		dev_warn(&pdev->dev, "using random MAC address %pM\n",
			 ndev->dev_addr);
	}

	db->emacrx_completed_flag = 1;
	emac_powerup(ndev);
	emac_reset(db);

	ether_setup(ndev);

	ndev->netdev_ops = &emac_netdev_ops;
	ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
	ndev->ethtool_ops = &emac_ethtool_ops;

	platform_set_drvdata(pdev, ndev);

	/* Carrier starts down, phylib will bring it up */
	netif_carrier_off(ndev);

	ret = register_netdev(ndev);
	if (ret) {
		dev_err(&pdev->dev, "Registering netdev failed!\n");
		ret = -ENODEV;
		goto out;
	}

	dev_info(&pdev->dev, "%s: at %p, IRQ %d MAC: %pM\n",
		 ndev->name, db->membase, ndev->irq, ndev->dev_addr);

	return 0;

out:
	dev_err(db->dev, "not found (%d).\n", ret);

	free_netdev(ndev);

	return ret;
}

static int emac_remove(struct platform_device *pdev)
{
	struct net_device *ndev = platform_get_drvdata(pdev);

	unregister_netdev(ndev);
	free_netdev(ndev);

	dev_dbg(&pdev->dev, "released and freed device\n");
	return 0;
}

static int emac_suspend(struct platform_device *dev, pm_message_t state)
{
	struct net_device *ndev = platform_get_drvdata(dev);

	netif_carrier_off(ndev);
	netif_device_detach(ndev);
	emac_shutdown(ndev);

	return 0;
}

static int emac_resume(struct platform_device *dev)
{
	struct net_device *ndev = platform_get_drvdata(dev);
	struct emac_board_info *db = netdev_priv(ndev);

	emac_reset(db);
	emac_init_device(ndev);
	netif_device_attach(ndev);

	return 0;
}

static const struct of_device_id emac_of_match[] = {
	{.compatible = "allwinner,sun4i-emac",},
	{},
};

MODULE_DEVICE_TABLE(of, emac_of_match);

static struct platform_driver emac_driver = {
	.driver = {
		.name = "sun4i-emac",
		.of_match_table = emac_of_match,
	},
	.probe = emac_probe,
	.remove = emac_remove,
	.suspend = emac_suspend,
	.resume = emac_resume,
};

module_platform_driver(emac_driver);

MODULE_AUTHOR("Stefan Roese <sr@denx.de>");
MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
MODULE_DESCRIPTION("Allwinner A10 emac network driver");
MODULE_LICENSE("GPL");