aboutsummaryrefslogtreecommitdiff
path: root/drivers/net/ethernet/arc/emac_main.c
blob: 9e160148726385b136b5cdedeee31118ac299b77 (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
/*
 * Copyright (C) 2004-2013 Synopsys, Inc. (www.synopsys.com)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Driver for the ARC EMAC 10100 (hardware revision 5)
 *
 * Contributors:
 *		Amit Bhor
 *		Sameer Dhavale
 *		Vineet Gupta
 */

#include <linux/etherdevice.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.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 "emac.h"

#define DRV_NAME	"arc_emac"
#define DRV_VERSION	"1.0"

/**
 * arc_emac_adjust_link - Adjust the PHY link duplex.
 * @ndev:	Pointer to the net_device structure.
 *
 * This function is called to change the duplex setting after auto negotiation
 * is done by the PHY.
 */
static void arc_emac_adjust_link(struct net_device *ndev)
{
	struct arc_emac_priv *priv = netdev_priv(ndev);
	struct phy_device *phy_dev = priv->phy_dev;
	unsigned int reg, state_changed = 0;

	if (priv->link != phy_dev->link) {
		priv->link = phy_dev->link;
		state_changed = 1;
	}

	if (priv->speed != phy_dev->speed) {
		priv->speed = phy_dev->speed;
		state_changed = 1;
	}

	if (priv->duplex != phy_dev->duplex) {
		reg = arc_reg_get(priv, R_CTRL);

		if (DUPLEX_FULL == phy_dev->duplex)
			reg |= ENFL_MASK;
		else
			reg &= ~ENFL_MASK;

		arc_reg_set(priv, R_CTRL, reg);
		priv->duplex = phy_dev->duplex;
		state_changed = 1;
	}

	if (state_changed)
		phy_print_status(phy_dev);
}

/**
 * arc_emac_get_settings - Get PHY settings.
 * @ndev:	Pointer to net_device structure.
 * @cmd:	Pointer to ethtool_cmd structure.
 *
 * This implements ethtool command for getting PHY settings. If PHY could
 * not be found, the function returns -ENODEV. This function calls the
 * relevant PHY ethtool API to get the PHY settings.
 * Issue "ethtool ethX" under linux prompt to execute this function.
 */
static int arc_emac_get_settings(struct net_device *ndev,
				 struct ethtool_cmd *cmd)
{
	struct arc_emac_priv *priv = netdev_priv(ndev);

	return phy_ethtool_gset(priv->phy_dev, cmd);
}

/**
 * arc_emac_set_settings - Set PHY settings as passed in the argument.
 * @ndev:	Pointer to net_device structure.
 * @cmd:	Pointer to ethtool_cmd structure.
 *
 * This implements ethtool command for setting various PHY settings. If PHY
 * could not be found, the function returns -ENODEV. This function calls the
 * relevant PHY ethtool API to set the PHY.
 * Issue e.g. "ethtool -s ethX speed 1000" under linux prompt to execute this
 * function.
 */
static int arc_emac_set_settings(struct net_device *ndev,
				 struct ethtool_cmd *cmd)
{
	struct arc_emac_priv *priv = netdev_priv(ndev);

	if (!capable(CAP_NET_ADMIN))
		return -EPERM;

	return phy_ethtool_sset(priv->phy_dev, cmd);
}

/**
 * arc_emac_get_drvinfo - Get EMAC driver information.
 * @ndev:	Pointer to net_device structure.
 * @info:	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 arc_emac_get_drvinfo(struct net_device *ndev,
				 struct ethtool_drvinfo *info)
{
	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
}

static const struct ethtool_ops arc_emac_ethtool_ops = {
	.get_settings	= arc_emac_get_settings,
	.set_settings	= arc_emac_set_settings,
	.get_drvinfo	= arc_emac_get_drvinfo,
	.get_link	= ethtool_op_get_link,
};

#define FIRST_OR_LAST_MASK	(FIRST_MASK | LAST_MASK)

/**
 * arc_emac_tx_clean - clears processed by EMAC Tx BDs.
 * @ndev:	Pointer to the network device.
 */
static void arc_emac_tx_clean(struct net_device *ndev)
{
	struct arc_emac_priv *priv = netdev_priv(ndev);
	struct net_device_stats *stats = &priv->stats;
	unsigned int i;

	for (i = 0; i < TX_BD_NUM; i++) {
		unsigned int *txbd_dirty = &priv->txbd_dirty;
		struct arc_emac_bd *txbd = &priv->txbd[*txbd_dirty];
		struct buffer_state *tx_buff = &priv->tx_buff[*txbd_dirty];
		struct sk_buff *skb = tx_buff->skb;
		unsigned int info = le32_to_cpu(txbd->info);

		if ((info & FOR_EMAC) || !txbd->data)
			break;

		if (unlikely(info & (DROP | DEFR | LTCL | UFLO))) {
			stats->tx_errors++;
			stats->tx_dropped++;

			if (info & DEFR)
				stats->tx_carrier_errors++;

			if (info & LTCL)
				stats->collisions++;

			if (info & UFLO)
				stats->tx_fifo_errors++;
		} else if (likely(info & FIRST_OR_LAST_MASK)) {
			stats->tx_packets++;
			stats->tx_bytes += skb->len;
		}

		dma_unmap_single(&ndev->dev, dma_unmap_addr(tx_buff, addr),
				 dma_unmap_len(tx_buff, len), DMA_TO_DEVICE);

		/* return the sk_buff to system */
		dev_kfree_skb_irq(skb);

		txbd->data = 0;
		txbd->info = 0;

		*txbd_dirty = (*txbd_dirty + 1) % TX_BD_NUM;

		if (netif_queue_stopped(ndev))
			netif_wake_queue(ndev);
	}
}

/**
 * arc_emac_rx - processing of Rx packets.
 * @ndev:	Pointer to the network device.
 * @budget:	How many BDs to process on 1 call.
 *
 * returns:	Number of processed BDs
 *
 * Iterate through Rx BDs and deliver received packages to upper layer.
 */
static int arc_emac_rx(struct net_device *ndev, int budget)
{
	struct arc_emac_priv *priv = netdev_priv(ndev);
	unsigned int work_done;

	for (work_done = 0; work_done < budget; work_done++) {
		unsigned int *last_rx_bd = &priv->last_rx_bd;
		struct net_device_stats *stats = &priv->stats;
		struct buffer_state *rx_buff = &priv->rx_buff[*last_rx_bd];
		struct arc_emac_bd *rxbd = &priv->rxbd[*last_rx_bd];
		unsigned int pktlen, info = le32_to_cpu(rxbd->info);
		struct sk_buff *skb;
		dma_addr_t addr;

		if (unlikely((info & OWN_MASK) == FOR_EMAC))
			break;

		/* Make a note that we saw a packet at this BD.
		 * So next time, driver starts from this + 1
		 */
		*last_rx_bd = (*last_rx_bd + 1) % RX_BD_NUM;

		if (unlikely((info & FIRST_OR_LAST_MASK) !=
			     FIRST_OR_LAST_MASK)) {
			/* We pre-allocate buffers of MTU size so incoming
			 * packets won't be split/chained.
			 */
			if (net_ratelimit())
				netdev_err(ndev, "incomplete packet received\n");

			/* Return ownership to EMAC */
			rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);
			stats->rx_errors++;
			stats->rx_length_errors++;
			continue;
		}

		pktlen = info & LEN_MASK;
		stats->rx_packets++;
		stats->rx_bytes += pktlen;
		skb = rx_buff->skb;
		skb_put(skb, pktlen);
		skb->dev = ndev;
		skb->protocol = eth_type_trans(skb, ndev);

		dma_unmap_single(&ndev->dev, dma_unmap_addr(rx_buff, addr),
				 dma_unmap_len(rx_buff, len), DMA_FROM_DEVICE);

		/* Prepare the BD for next cycle */
		rx_buff->skb = netdev_alloc_skb_ip_align(ndev,
							 EMAC_BUFFER_SIZE);
		if (unlikely(!rx_buff->skb)) {
			stats->rx_errors++;
			/* Because receive_skb is below, increment rx_dropped */
			stats->rx_dropped++;
			continue;
		}

		/* receive_skb only if new skb was allocated to avoid holes */
		netif_receive_skb(skb);

		addr = dma_map_single(&ndev->dev, (void *)rx_buff->skb->data,
				      EMAC_BUFFER_SIZE, DMA_FROM_DEVICE);
		if (dma_mapping_error(&ndev->dev, addr)) {
			if (net_ratelimit())
				netdev_err(ndev, "cannot dma map\n");
			dev_kfree_skb(rx_buff->skb);
			stats->rx_errors++;
			continue;
		}
		dma_unmap_addr_set(rx_buff, addr, addr);
		dma_unmap_len_set(rx_buff, len, EMAC_BUFFER_SIZE);

		rxbd->data = cpu_to_le32(addr);

		/* Make sure pointer to data buffer is set */
		wmb();

		/* Return ownership to EMAC */
		rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);
	}

	return work_done;
}

/**
 * arc_emac_poll - NAPI poll handler.
 * @napi:	Pointer to napi_struct structure.
 * @budget:	How many BDs to process on 1 call.
 *
 * returns:	Number of processed BDs
 */
static int arc_emac_poll(struct napi_struct *napi, int budget)
{
	struct net_device *ndev = napi->dev;
	struct arc_emac_priv *priv = netdev_priv(ndev);
	unsigned int work_done;

	arc_emac_tx_clean(ndev);

	work_done = arc_emac_rx(ndev, budget);
	if (work_done < budget) {
		napi_complete(napi);
		arc_reg_or(priv, R_ENABLE, RXINT_MASK);
	}

	return work_done;
}

/**
 * arc_emac_intr - Global interrupt handler for EMAC.
 * @irq:		irq number.
 * @dev_instance:	device instance.
 *
 * returns: IRQ_HANDLED for all cases.
 *
 * ARC EMAC has only 1 interrupt line, and depending on bits raised in
 * STATUS register we may tell what is a reason for interrupt to fire.
 */
static irqreturn_t arc_emac_intr(int irq, void *dev_instance)
{
	struct net_device *ndev = dev_instance;
	struct arc_emac_priv *priv = netdev_priv(ndev);
	struct net_device_stats *stats = &priv->stats;
	unsigned int status;

	status = arc_reg_get(priv, R_STATUS);
	status &= ~MDIO_MASK;

	/* Reset all flags except "MDIO complete" */
	arc_reg_set(priv, R_STATUS, status);

	if (status & RXINT_MASK) {
		if (likely(napi_schedule_prep(&priv->napi))) {
			arc_reg_clr(priv, R_ENABLE, RXINT_MASK);
			__napi_schedule(&priv->napi);
		}
	}

	if (status & ERR_MASK) {
		/* MSER/RXCR/RXFR/RXFL interrupt fires on corresponding
		 * 8-bit error counter overrun.
		 */

		if (status & MSER_MASK) {
			stats->rx_missed_errors += 0x100;
			stats->rx_errors += 0x100;
		}

		if (status & RXCR_MASK) {
			stats->rx_crc_errors += 0x100;
			stats->rx_errors += 0x100;
		}

		if (status & RXFR_MASK) {
			stats->rx_frame_errors += 0x100;
			stats->rx_errors += 0x100;
		}

		if (status & RXFL_MASK) {
			stats->rx_over_errors += 0x100;
			stats->rx_errors += 0x100;
		}
	}

	return IRQ_HANDLED;
}

/**
 * arc_emac_open - Open the network device.
 * @ndev:	Pointer to the network device.
 *
 * returns: 0, on success or non-zero error value on failure.
 *
 * This function sets the MAC address, requests and enables an IRQ
 * for the EMAC device and starts the Tx queue.
 * It also connects to the phy device.
 */
static int arc_emac_open(struct net_device *ndev)
{
	struct arc_emac_priv *priv = netdev_priv(ndev);
	struct phy_device *phy_dev = priv->phy_dev;
	int i;

	phy_dev->autoneg = AUTONEG_ENABLE;
	phy_dev->speed = 0;
	phy_dev->duplex = 0;
	phy_dev->advertising = phy_dev->supported;

	if (priv->max_speed > 100) {
		phy_dev->advertising &= PHY_GBIT_FEATURES;
	} else if (priv->max_speed <= 100) {
		phy_dev->advertising &= PHY_BASIC_FEATURES;
		if (priv->max_speed <= 10) {
			phy_dev->advertising &= ~SUPPORTED_100baseT_Half;
			phy_dev->advertising &= ~SUPPORTED_100baseT_Full;
		}
	}

	priv->last_rx_bd = 0;

	/* Allocate and set buffers for Rx BD's */
	for (i = 0; i < RX_BD_NUM; i++) {
		dma_addr_t addr;
		unsigned int *last_rx_bd = &priv->last_rx_bd;
		struct arc_emac_bd *rxbd = &priv->rxbd[*last_rx_bd];
		struct buffer_state *rx_buff = &priv->rx_buff[*last_rx_bd];

		rx_buff->skb = netdev_alloc_skb_ip_align(ndev,
							 EMAC_BUFFER_SIZE);
		if (unlikely(!rx_buff->skb))
			return -ENOMEM;

		addr = dma_map_single(&ndev->dev, (void *)rx_buff->skb->data,
				      EMAC_BUFFER_SIZE, DMA_FROM_DEVICE);
		if (dma_mapping_error(&ndev->dev, addr)) {
			netdev_err(ndev, "cannot dma map\n");
			dev_kfree_skb(rx_buff->skb);
			return -ENOMEM;
		}
		dma_unmap_addr_set(rx_buff, addr, addr);
		dma_unmap_len_set(rx_buff, len, EMAC_BUFFER_SIZE);

		rxbd->data = cpu_to_le32(addr);

		/* Make sure pointer to data buffer is set */
		wmb();

		/* Return ownership to EMAC */
		rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);

		*last_rx_bd = (*last_rx_bd + 1) % RX_BD_NUM;
	}

	/* Clean Tx BD's */
	memset(priv->txbd, 0, TX_RING_SZ);

	/* Initialize logical address filter */
	arc_reg_set(priv, R_LAFL, 0);
	arc_reg_set(priv, R_LAFH, 0);

	/* Set BD ring pointers for device side */
	arc_reg_set(priv, R_RX_RING, (unsigned int)priv->rxbd_dma);
	arc_reg_set(priv, R_TX_RING, (unsigned int)priv->txbd_dma);

	/* Enable interrupts */
	arc_reg_set(priv, R_ENABLE, RXINT_MASK | ERR_MASK);

	/* Set CONTROL */
	arc_reg_set(priv, R_CTRL,
		     (RX_BD_NUM << 24) |	/* RX BD table length */
		     (TX_BD_NUM << 16) |	/* TX BD table length */
		     TXRN_MASK | RXRN_MASK);

	napi_enable(&priv->napi);

	/* Enable EMAC */
	arc_reg_or(priv, R_CTRL, EN_MASK);

	phy_start_aneg(priv->phy_dev);

	netif_start_queue(ndev);

	return 0;
}

/**
 * arc_emac_stop - Close the network device.
 * @ndev:	Pointer to the network device.
 *
 * This function stops the Tx queue, disables interrupts and frees the IRQ for
 * the EMAC device.
 * It also disconnects the PHY device associated with the EMAC device.
 */
static int arc_emac_stop(struct net_device *ndev)
{
	struct arc_emac_priv *priv = netdev_priv(ndev);

	napi_disable(&priv->napi);
	netif_stop_queue(ndev);

	/* Disable interrupts */
	arc_reg_clr(priv, R_ENABLE, RXINT_MASK | ERR_MASK);

	/* Disable EMAC */
	arc_reg_clr(priv, R_CTRL, EN_MASK);

	return 0;
}

/**
 * arc_emac_stats - Get system network statistics.
 * @ndev:	Pointer to net_device structure.
 *
 * Returns the address of the device statistics structure.
 * Statistics are updated in interrupt handler.
 */
static struct net_device_stats *arc_emac_stats(struct net_device *ndev)
{
	struct arc_emac_priv *priv = netdev_priv(ndev);
	struct net_device_stats *stats = &priv->stats;
	unsigned long miss, rxerr;
	u8 rxcrc, rxfram, rxoflow;

	rxerr = arc_reg_get(priv, R_RXERR);
	miss = arc_reg_get(priv, R_MISS);

	rxcrc = rxerr;
	rxfram = rxerr >> 8;
	rxoflow = rxerr >> 16;

	stats->rx_errors += miss;
	stats->rx_errors += rxcrc + rxfram + rxoflow;

	stats->rx_over_errors += rxoflow;
	stats->rx_frame_errors += rxfram;
	stats->rx_crc_errors += rxcrc;
	stats->rx_missed_errors += miss;

	return stats;
}

/**
 * arc_emac_tx - Starts the data transmission.
 * @skb:	sk_buff pointer that contains data to be Transmitted.
 * @ndev:	Pointer to net_device structure.
 *
 * returns: NETDEV_TX_OK, on success
 *		NETDEV_TX_BUSY, if any of the descriptors are not free.
 *
 * This function is invoked from upper layers to initiate transmission.
 */
static int arc_emac_tx(struct sk_buff *skb, struct net_device *ndev)
{
	struct arc_emac_priv *priv = netdev_priv(ndev);
	unsigned int len, *txbd_curr = &priv->txbd_curr;
	struct net_device_stats *stats = &priv->stats;
	__le32 *info = &priv->txbd[*txbd_curr].info;
	dma_addr_t addr;

	if (skb_padto(skb, ETH_ZLEN))
		return NETDEV_TX_OK;

	len = max_t(unsigned int, ETH_ZLEN, skb->len);

	/* EMAC still holds this buffer in its possession.
	 * CPU must not modify this buffer descriptor
	 */
	if (unlikely((le32_to_cpu(*info) & OWN_MASK) == FOR_EMAC)) {
		netif_stop_queue(ndev);
		return NETDEV_TX_BUSY;
	}

	addr = dma_map_single(&ndev->dev, (void *)skb->data, len,
			      DMA_TO_DEVICE);

	if (unlikely(dma_mapping_error(&ndev->dev, addr))) {
		stats->tx_dropped++;
		stats->tx_errors++;
		dev_kfree_skb(skb);
		return NETDEV_TX_OK;
	}
	dma_unmap_addr_set(&priv->tx_buff[*txbd_curr], addr, addr);
	dma_unmap_len_set(&priv->tx_buff[*txbd_curr], len, len);

	priv->tx_buff[*txbd_curr].skb = skb;
	priv->txbd[*txbd_curr].data = cpu_to_le32(addr);

	/* Make sure pointer to data buffer is set */
	wmb();

	*info = cpu_to_le32(FOR_EMAC | FIRST_OR_LAST_MASK | len);

	/* Increment index to point to the next BD */
	*txbd_curr = (*txbd_curr + 1) % TX_BD_NUM;

	/* Get "info" of the next BD */
	info = &priv->txbd[*txbd_curr].info;

	/* Check if if Tx BD ring is full - next BD is still owned by EMAC */
	if (unlikely((le32_to_cpu(*info) & OWN_MASK) == FOR_EMAC))
		netif_stop_queue(ndev);

	arc_reg_set(priv, R_STATUS, TXPL_MASK);

	skb_tx_timestamp(skb);

	return NETDEV_TX_OK;
}

/**
 * arc_emac_set_address - Set the MAC address for this device.
 * @ndev:	Pointer to net_device structure.
 * @p:		6 byte Address to be written as MAC address.
 *
 * This function copies the HW address from the sockaddr structure to the
 * net_device structure and updates the address in HW.
 *
 * returns:	-EBUSY if the net device is busy or 0 if the address is set
 *		successfully.
 */
static int arc_emac_set_address(struct net_device *ndev, void *p)
{
	struct arc_emac_priv *priv = netdev_priv(ndev);
	struct sockaddr *addr = p;
	unsigned int addr_low, addr_hi;

	if (netif_running(ndev))
		return -EBUSY;

	if (!is_valid_ether_addr(addr->sa_data))
		return -EADDRNOTAVAIL;

	memcpy(ndev->dev_addr, addr->sa_data, ndev->addr_len);

	addr_low = le32_to_cpu(*(__le32 *) &ndev->dev_addr[0]);
	addr_hi = le16_to_cpu(*(__le16 *) &ndev->dev_addr[4]);

	arc_reg_set(priv, R_ADDRL, addr_low);
	arc_reg_set(priv, R_ADDRH, addr_hi);

	return 0;
}

static const struct net_device_ops arc_emac_netdev_ops = {
	.ndo_open		= arc_emac_open,
	.ndo_stop		= arc_emac_stop,
	.ndo_start_xmit		= arc_emac_tx,
	.ndo_set_mac_address	= arc_emac_set_address,
	.ndo_get_stats		= arc_emac_stats,
};

static int arc_emac_probe(struct platform_device *pdev)
{
	struct resource res_regs, res_irq;
	struct device_node *phy_node;
	struct arc_emac_priv *priv;
	struct net_device *ndev;
	const char *mac_addr;
	unsigned int id, clock_frequency;
	int err;

	if (!pdev->dev.of_node)
		return -ENODEV;

	/* Get PHY from device tree */
	phy_node = of_parse_phandle(pdev->dev.of_node, "phy", 0);
	if (!phy_node) {
		dev_err(&pdev->dev, "failed to retrieve phy description from device tree\n");
		return -ENODEV;
	}

	/* Get EMAC registers base address from device tree */
	err = of_address_to_resource(pdev->dev.of_node, 0, &res_regs);
	if (err) {
		dev_err(&pdev->dev, "failed to retrieve registers base from device tree\n");
		return -ENODEV;
	}

	/* Get CPU clock frequency from device tree */
	if (of_property_read_u32(pdev->dev.of_node, "clock-frequency",
				 &clock_frequency)) {
		dev_err(&pdev->dev, "failed to retrieve <clock-frequency> from device tree\n");
		return -EINVAL;
	}

	/* Get IRQ from device tree */
	err = of_irq_to_resource(pdev->dev.of_node, 0, &res_irq);
	if (!err) {
		dev_err(&pdev->dev, "failed to retrieve <irq> value from device tree\n");
		return -ENODEV;
	}

	ndev = alloc_etherdev(sizeof(struct arc_emac_priv));
	if (!ndev)
		return -ENOMEM;

	SET_NETDEV_DEV(ndev, &pdev->dev);

	ndev->netdev_ops = &arc_emac_netdev_ops;
	ndev->ethtool_ops = &arc_emac_ethtool_ops;
	ndev->watchdog_timeo = TX_TIMEOUT;
	/* FIXME :: no multicast support yet */
	ndev->flags &= ~IFF_MULTICAST;

	priv = netdev_priv(ndev);
	priv->dev = &pdev->dev;
	priv->ndev = ndev;

	priv->regs = devm_ioremap_resource(&pdev->dev, &res_regs);
	if (IS_ERR(priv->regs)) {
		err = PTR_ERR(priv->regs);
		goto out;
	}
	dev_dbg(&pdev->dev, "Registers base address is 0x%p\n", priv->regs);

	id = arc_reg_get(priv, R_ID);

	/* Check for EMAC revision 5 or 7, magic number */
	if (!(id == 0x0005fd02 || id == 0x0007fd02)) {
		dev_err(&pdev->dev, "ARC EMAC not detected, id=0x%x\n", id);
		err = -ENODEV;
		goto out;
	}
	dev_info(&pdev->dev, "ARC EMAC detected with id: 0x%x\n", id);

	/* Set poll rate so that it polls every 1 ms */
	arc_reg_set(priv, R_POLLRATE, clock_frequency / 1000000);

	/* Get max speed of operation from device tree */
	if (of_property_read_u32(pdev->dev.of_node, "max-speed",
				 &priv->max_speed)) {
		dev_err(&pdev->dev, "failed to retrieve <max-speed> from device tree\n");
		err = -EINVAL;
		goto out;
	}

	ndev->irq = res_irq.start;
	dev_info(&pdev->dev, "IRQ is %d\n", ndev->irq);

	/* Register interrupt handler for device */
	err = devm_request_irq(&pdev->dev, ndev->irq, arc_emac_intr, 0,
			       ndev->name, ndev);
	if (err) {
		dev_err(&pdev->dev, "could not allocate IRQ\n");
		goto out;
	}

	/* Get MAC address from device tree */
	mac_addr = of_get_mac_address(pdev->dev.of_node);

	if (!mac_addr || !is_valid_ether_addr(mac_addr))
		eth_hw_addr_random(ndev);
	else
		memcpy(ndev->dev_addr, mac_addr, ETH_ALEN);

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

	/* Do 1 allocation instead of 2 separate ones for Rx and Tx BD rings */
	priv->rxbd = dmam_alloc_coherent(&pdev->dev, RX_RING_SZ + TX_RING_SZ,
					 &priv->rxbd_dma, GFP_KERNEL);

	if (!priv->rxbd) {
		dev_err(&pdev->dev, "failed to allocate data buffers\n");
		err = -ENOMEM;
		goto out;
	}

	priv->txbd = priv->rxbd + RX_BD_NUM;

	priv->txbd_dma = priv->rxbd_dma + RX_RING_SZ;
	dev_dbg(&pdev->dev, "EMAC Device addr: Rx Ring [0x%x], Tx Ring[%x]\n",
		(unsigned int)priv->rxbd_dma, (unsigned int)priv->txbd_dma);

	err = arc_mdio_probe(pdev, priv);
	if (err) {
		dev_err(&pdev->dev, "failed to probe MII bus\n");
		goto out;
	}

	priv->phy_dev = of_phy_connect(ndev, phy_node, arc_emac_adjust_link, 0,
				       PHY_INTERFACE_MODE_MII);
	if (!priv->phy_dev) {
		dev_err(&pdev->dev, "of_phy_connect() failed\n");
		err = -ENODEV;
		goto out;
	}

	dev_info(&pdev->dev, "connected to %s phy with id 0x%x\n",
		 priv->phy_dev->drv->name, priv->phy_dev->phy_id);

	netif_napi_add(ndev, &priv->napi, arc_emac_poll, ARC_EMAC_NAPI_WEIGHT);

	err = register_netdev(ndev);
	if (err) {
		netif_napi_del(&priv->napi);
		dev_err(&pdev->dev, "failed to register network device\n");
		goto out;
	}

	return 0;

out:
	free_netdev(ndev);
	return err;
}

static int arc_emac_remove(struct platform_device *pdev)
{
	struct net_device *ndev = platform_get_drvdata(pdev);
	struct arc_emac_priv *priv = netdev_priv(ndev);

	phy_disconnect(priv->phy_dev);
	priv->phy_dev = NULL;
	arc_mdio_remove(priv);
	unregister_netdev(ndev);
	netif_napi_del(&priv->napi);
	free_netdev(ndev);

	return 0;
}

static const struct of_device_id arc_emac_dt_ids[] = {
	{ .compatible = "snps,arc-emac" },
	{ /* Sentinel */ }
};
MODULE_DEVICE_TABLE(of, arc_emac_dt_ids);

static struct platform_driver arc_emac_driver = {
	.probe = arc_emac_probe,
	.remove = arc_emac_remove,
	.driver = {
		.name = DRV_NAME,
		.owner = THIS_MODULE,
		.of_match_table  = arc_emac_dt_ids,
		},
};

module_platform_driver(arc_emac_driver);

MODULE_AUTHOR("Alexey Brodkin <abrodkin@synopsys.com>");
MODULE_DESCRIPTION("ARC EMAC driver");
MODULE_LICENSE("GPL");