summaryrefslogtreecommitdiffstats
path: root/drivers/net/ethernet/lantiq_xrx200.c
blob: 0da09ea81980981b809f9b2c7eb2956e0ae4198e (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
// SPDX-License-Identifier: GPL-2.0
/*
 * Lantiq / Intel PMAC driver for XRX200 SoCs
 *
 * Copyright (C) 2010 Lantiq Deutschland
 * Copyright (C) 2012 John Crispin <john@phrozen.org>
 * Copyright (C) 2017 - 2018 Hauke Mehrtens <hauke@hauke-m.de>
 */

#include <linux/etherdevice.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/delay.h>

#include <linux/if_vlan.h>

#include <linux/of_net.h>
#include <linux/of_platform.h>

#include <xway_dma.h>

/* DMA */
#define XRX200_DMA_DATA_LEN	(SZ_64K - 1)
#define XRX200_DMA_RX		0
#define XRX200_DMA_TX		1
#define XRX200_DMA_BURST_LEN	8

/* cpu port mac */
#define PMAC_RX_IPG		0x0024
#define PMAC_RX_IPG_MASK	0xf

#define PMAC_HD_CTL		0x0000
/* Add Ethernet header to packets from DMA to PMAC */
#define PMAC_HD_CTL_ADD		BIT(0)
/* Add VLAN tag to Packets from DMA to PMAC */
#define PMAC_HD_CTL_TAG		BIT(1)
/* Add CRC to packets from DMA to PMAC */
#define PMAC_HD_CTL_AC		BIT(2)
/* Add status header to packets from PMAC to DMA */
#define PMAC_HD_CTL_AS		BIT(3)
/* Remove CRC from packets from PMAC to DMA */
#define PMAC_HD_CTL_RC		BIT(4)
/* Remove Layer-2 header from packets from PMAC to DMA */
#define PMAC_HD_CTL_RL2		BIT(5)
/* Status header is present from DMA to PMAC */
#define PMAC_HD_CTL_RXSH	BIT(6)
/* Add special tag from PMAC to switch */
#define PMAC_HD_CTL_AST		BIT(7)
/* Remove specail Tag from PMAC to DMA */
#define PMAC_HD_CTL_RST		BIT(8)
/* Check CRC from DMA to PMAC */
#define PMAC_HD_CTL_CCRC	BIT(9)
/* Enable reaction to Pause frames in the PMAC */
#define PMAC_HD_CTL_FC		BIT(10)

struct xrx200_chan {
	int tx_free;

	struct napi_struct napi;
	struct ltq_dma_channel dma;
	struct sk_buff *skb[LTQ_DESC_NUM];

	struct xrx200_priv *priv;
};

struct xrx200_priv {
	struct clk *clk;

	struct xrx200_chan chan_tx;
	struct xrx200_chan chan_rx;

	struct net_device *net_dev;
	struct device *dev;

	__iomem void *pmac_reg;
};

static u32 xrx200_pmac_r32(struct xrx200_priv *priv, u32 offset)
{
	return __raw_readl(priv->pmac_reg + offset);
}

static void xrx200_pmac_w32(struct xrx200_priv *priv, u32 val, u32 offset)
{
	__raw_writel(val, priv->pmac_reg + offset);
}

static void xrx200_pmac_mask(struct xrx200_priv *priv, u32 clear, u32 set,
			     u32 offset)
{
	u32 val = xrx200_pmac_r32(priv, offset);

	val &= ~(clear);
	val |= set;
	xrx200_pmac_w32(priv, val, offset);
}

/* drop all the packets from the DMA ring */
static void xrx200_flush_dma(struct xrx200_chan *ch)
{
	int i;

	for (i = 0; i < LTQ_DESC_NUM; i++) {
		struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];

		if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) != LTQ_DMA_C)
			break;

		desc->ctl = LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) |
			    (ch->priv->net_dev->mtu + VLAN_ETH_HLEN +
			     ETH_FCS_LEN);
		ch->dma.desc++;
		ch->dma.desc %= LTQ_DESC_NUM;
	}
}

static int xrx200_open(struct net_device *net_dev)
{
	struct xrx200_priv *priv = netdev_priv(net_dev);

	napi_enable(&priv->chan_tx.napi);
	ltq_dma_open(&priv->chan_tx.dma);
	ltq_dma_enable_irq(&priv->chan_tx.dma);

	napi_enable(&priv->chan_rx.napi);
	ltq_dma_open(&priv->chan_rx.dma);
	/* The boot loader does not always deactivate the receiving of frames
	 * on the ports and then some packets queue up in the PPE buffers.
	 * They already passed the PMAC so they do not have the tags
	 * configured here. Read the these packets here and drop them.
	 * The HW should have written them into memory after 10us
	 */
	usleep_range(20, 40);
	xrx200_flush_dma(&priv->chan_rx);
	ltq_dma_enable_irq(&priv->chan_rx.dma);

	netif_wake_queue(net_dev);

	return 0;
}

static int xrx200_close(struct net_device *net_dev)
{
	struct xrx200_priv *priv = netdev_priv(net_dev);

	netif_stop_queue(net_dev);

	napi_disable(&priv->chan_rx.napi);
	ltq_dma_close(&priv->chan_rx.dma);

	napi_disable(&priv->chan_tx.napi);
	ltq_dma_close(&priv->chan_tx.dma);

	return 0;
}

static int xrx200_alloc_skb(struct xrx200_chan *ch)
{
	int len = ch->priv->net_dev->mtu + VLAN_ETH_HLEN + ETH_FCS_LEN;
	struct sk_buff *skb = ch->skb[ch->dma.desc];
	dma_addr_t mapping;
	int ret = 0;

	ch->skb[ch->dma.desc] = netdev_alloc_skb_ip_align(ch->priv->net_dev,
							  len);
	if (!ch->skb[ch->dma.desc]) {
		ret = -ENOMEM;
		goto skip;
	}

	mapping = dma_map_single(ch->priv->dev, ch->skb[ch->dma.desc]->data,
				 len, DMA_FROM_DEVICE);
	if (unlikely(dma_mapping_error(ch->priv->dev, mapping))) {
		dev_kfree_skb_any(ch->skb[ch->dma.desc]);
		ch->skb[ch->dma.desc] = skb;
		ret = -ENOMEM;
		goto skip;
	}

	ch->dma.desc_base[ch->dma.desc].addr = mapping;
	/* Make sure the address is written before we give it to HW */
	wmb();
skip:
	ch->dma.desc_base[ch->dma.desc].ctl =
		LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) | len;

	return ret;
}

static int xrx200_hw_receive(struct xrx200_chan *ch)
{
	struct xrx200_priv *priv = ch->priv;
	struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
	struct sk_buff *skb = ch->skb[ch->dma.desc];
	int len = (desc->ctl & LTQ_DMA_SIZE_MASK);
	struct net_device *net_dev = priv->net_dev;
	int ret;

	ret = xrx200_alloc_skb(ch);

	ch->dma.desc++;
	ch->dma.desc %= LTQ_DESC_NUM;

	if (ret) {
		net_dev->stats.rx_dropped++;
		netdev_err(net_dev, "failed to allocate new rx buffer\n");
		return ret;
	}

	skb_put(skb, len);
	skb->protocol = eth_type_trans(skb, net_dev);
	netif_receive_skb(skb);
	net_dev->stats.rx_packets++;
	net_dev->stats.rx_bytes += len - ETH_FCS_LEN;

	return 0;
}

static int xrx200_poll_rx(struct napi_struct *napi, int budget)
{
	struct xrx200_chan *ch = container_of(napi,
				struct xrx200_chan, napi);
	int rx = 0;
	int ret;

	while (rx < budget) {
		struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];

		if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) == LTQ_DMA_C) {
			ret = xrx200_hw_receive(ch);
			if (ret)
				return ret;
			rx++;
		} else {
			break;
		}
	}

	if (rx < budget) {
		if (napi_complete_done(&ch->napi, rx))
			ltq_dma_enable_irq(&ch->dma);
	}

	return rx;
}

static int xrx200_tx_housekeeping(struct napi_struct *napi, int budget)
{
	struct xrx200_chan *ch = container_of(napi,
				struct xrx200_chan, napi);
	struct net_device *net_dev = ch->priv->net_dev;
	int pkts = 0;
	int bytes = 0;

	netif_tx_lock(net_dev);
	while (pkts < budget) {
		struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->tx_free];

		if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) == LTQ_DMA_C) {
			struct sk_buff *skb = ch->skb[ch->tx_free];

			pkts++;
			bytes += skb->len;
			ch->skb[ch->tx_free] = NULL;
			consume_skb(skb);
			memset(&ch->dma.desc_base[ch->tx_free], 0,
			       sizeof(struct ltq_dma_desc));
			ch->tx_free++;
			ch->tx_free %= LTQ_DESC_NUM;
		} else {
			break;
		}
	}

	net_dev->stats.tx_packets += pkts;
	net_dev->stats.tx_bytes += bytes;
	netdev_completed_queue(ch->priv->net_dev, pkts, bytes);

	netif_tx_unlock(net_dev);
	if (netif_queue_stopped(net_dev))
		netif_wake_queue(net_dev);

	if (pkts < budget) {
		if (napi_complete_done(&ch->napi, pkts))
			ltq_dma_enable_irq(&ch->dma);
	}

	return pkts;
}

static netdev_tx_t xrx200_start_xmit(struct sk_buff *skb,
				     struct net_device *net_dev)
{
	struct xrx200_priv *priv = netdev_priv(net_dev);
	struct xrx200_chan *ch = &priv->chan_tx;
	struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
	u32 byte_offset;
	dma_addr_t mapping;
	int len;

	skb->dev = net_dev;
	if (skb_put_padto(skb, ETH_ZLEN)) {
		net_dev->stats.tx_dropped++;
		return NETDEV_TX_OK;
	}

	len = skb->len;

	if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) || ch->skb[ch->dma.desc]) {
		netdev_err(net_dev, "tx ring full\n");
		netif_stop_queue(net_dev);
		return NETDEV_TX_BUSY;
	}

	ch->skb[ch->dma.desc] = skb;

	mapping = dma_map_single(priv->dev, skb->data, len, DMA_TO_DEVICE);
	if (unlikely(dma_mapping_error(priv->dev, mapping)))
		goto err_drop;

	/* dma needs to start on a burst length value aligned address */
	byte_offset = mapping % (XRX200_DMA_BURST_LEN * 4);

	desc->addr = mapping - byte_offset;
	/* Make sure the address is written before we give it to HW */
	wmb();
	desc->ctl = LTQ_DMA_OWN | LTQ_DMA_SOP | LTQ_DMA_EOP |
		LTQ_DMA_TX_OFFSET(byte_offset) | (len & LTQ_DMA_SIZE_MASK);
	ch->dma.desc++;
	ch->dma.desc %= LTQ_DESC_NUM;
	if (ch->dma.desc == ch->tx_free)
		netif_stop_queue(net_dev);

	netdev_sent_queue(net_dev, len);

	return NETDEV_TX_OK;

err_drop:
	dev_kfree_skb(skb);
	net_dev->stats.tx_dropped++;
	net_dev->stats.tx_errors++;
	return NETDEV_TX_OK;
}

static int
xrx200_change_mtu(struct net_device *net_dev, int new_mtu)
{
	struct xrx200_priv *priv = netdev_priv(net_dev);
	struct xrx200_chan *ch_rx = &priv->chan_rx;
	int old_mtu = net_dev->mtu;
	bool running = false;
	struct sk_buff *skb;
	int curr_desc;
	int ret = 0;

	net_dev->mtu = new_mtu;

	if (new_mtu <= old_mtu)
		return ret;

	running = netif_running(net_dev);
	if (running) {
		napi_disable(&ch_rx->napi);
		ltq_dma_close(&ch_rx->dma);
	}

	xrx200_poll_rx(&ch_rx->napi, LTQ_DESC_NUM);
	curr_desc = ch_rx->dma.desc;

	for (ch_rx->dma.desc = 0; ch_rx->dma.desc < LTQ_DESC_NUM;
	     ch_rx->dma.desc++) {
		skb = ch_rx->skb[ch_rx->dma.desc];
		ret = xrx200_alloc_skb(ch_rx);
		if (ret) {
			net_dev->mtu = old_mtu;
			break;
		}
		dev_kfree_skb_any(skb);
	}

	ch_rx->dma.desc = curr_desc;
	if (running) {
		napi_enable(&ch_rx->napi);
		ltq_dma_open(&ch_rx->dma);
		ltq_dma_enable_irq(&ch_rx->dma);
	}

	return ret;
}

static const struct net_device_ops xrx200_netdev_ops = {
	.ndo_open		= xrx200_open,
	.ndo_stop		= xrx200_close,
	.ndo_start_xmit		= xrx200_start_xmit,
	.ndo_change_mtu		= xrx200_change_mtu,
	.ndo_set_mac_address	= eth_mac_addr,
	.ndo_validate_addr	= eth_validate_addr,
};

static irqreturn_t xrx200_dma_irq(int irq, void *ptr)
{
	struct xrx200_chan *ch = ptr;

	if (napi_schedule_prep(&ch->napi)) {
		ltq_dma_disable_irq(&ch->dma);
		__napi_schedule(&ch->napi);
	}

	ltq_dma_ack_irq(&ch->dma);

	return IRQ_HANDLED;
}

static int xrx200_dma_init(struct xrx200_priv *priv)
{
	struct xrx200_chan *ch_rx = &priv->chan_rx;
	struct xrx200_chan *ch_tx = &priv->chan_tx;
	int ret = 0;
	int i;

	ltq_dma_init_port(DMA_PORT_ETOP, XRX200_DMA_BURST_LEN,
			  XRX200_DMA_BURST_LEN);

	ch_rx->dma.nr = XRX200_DMA_RX;
	ch_rx->dma.dev = priv->dev;
	ch_rx->priv = priv;

	ltq_dma_alloc_rx(&ch_rx->dma);
	for (ch_rx->dma.desc = 0; ch_rx->dma.desc < LTQ_DESC_NUM;
	     ch_rx->dma.desc++) {
		ret = xrx200_alloc_skb(ch_rx);
		if (ret)
			goto rx_free;
	}
	ch_rx->dma.desc = 0;
	ret = devm_request_irq(priv->dev, ch_rx->dma.irq, xrx200_dma_irq, 0,
			       "xrx200_net_rx", &priv->chan_rx);
	if (ret) {
		dev_err(priv->dev, "failed to request RX irq %d\n",
			ch_rx->dma.irq);
		goto rx_ring_free;
	}

	ch_tx->dma.nr = XRX200_DMA_TX;
	ch_tx->dma.dev = priv->dev;
	ch_tx->priv = priv;

	ltq_dma_alloc_tx(&ch_tx->dma);
	ret = devm_request_irq(priv->dev, ch_tx->dma.irq, xrx200_dma_irq, 0,
			       "xrx200_net_tx", &priv->chan_tx);
	if (ret) {
		dev_err(priv->dev, "failed to request TX irq %d\n",
			ch_tx->dma.irq);
		goto tx_free;
	}

	return ret;

tx_free:
	ltq_dma_free(&ch_tx->dma);

rx_ring_free:
	/* free the allocated RX ring */
	for (i = 0; i < LTQ_DESC_NUM; i++) {
		if (priv->chan_rx.skb[i])
			dev_kfree_skb_any(priv->chan_rx.skb[i]);
	}

rx_free:
	ltq_dma_free(&ch_rx->dma);
	return ret;
}

static void xrx200_hw_cleanup(struct xrx200_priv *priv)
{
	int i;

	ltq_dma_free(&priv->chan_tx.dma);
	ltq_dma_free(&priv->chan_rx.dma);

	/* free the allocated RX ring */
	for (i = 0; i < LTQ_DESC_NUM; i++)
		dev_kfree_skb_any(priv->chan_rx.skb[i]);
}

static int xrx200_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct xrx200_priv *priv;
	struct net_device *net_dev;
	int err;

	/* alloc the network device */
	net_dev = devm_alloc_etherdev(dev, sizeof(struct xrx200_priv));
	if (!net_dev)
		return -ENOMEM;

	priv = netdev_priv(net_dev);
	priv->net_dev = net_dev;
	priv->dev = dev;

	net_dev->netdev_ops = &xrx200_netdev_ops;
	SET_NETDEV_DEV(net_dev, dev);
	net_dev->min_mtu = ETH_ZLEN;
	net_dev->max_mtu = XRX200_DMA_DATA_LEN - VLAN_ETH_HLEN - ETH_FCS_LEN;

	/* load the memory ranges */
	priv->pmac_reg = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
	if (IS_ERR(priv->pmac_reg))
		return PTR_ERR(priv->pmac_reg);

	priv->chan_rx.dma.irq = platform_get_irq_byname(pdev, "rx");
	if (priv->chan_rx.dma.irq < 0)
		return -ENOENT;
	priv->chan_tx.dma.irq = platform_get_irq_byname(pdev, "tx");
	if (priv->chan_tx.dma.irq < 0)
		return -ENOENT;

	/* get the clock */
	priv->clk = devm_clk_get(dev, NULL);
	if (IS_ERR(priv->clk)) {
		dev_err(dev, "failed to get clock\n");
		return PTR_ERR(priv->clk);
	}

	err = of_get_ethdev_address(np, net_dev);
	if (err)
		eth_hw_addr_random(net_dev);

	/* bring up the dma engine and IP core */
	err = xrx200_dma_init(priv);
	if (err)
		return err;

	/* enable clock gate */
	err = clk_prepare_enable(priv->clk);
	if (err)
		goto err_uninit_dma;

	/* set IPG to 12 */
	xrx200_pmac_mask(priv, PMAC_RX_IPG_MASK, 0xb, PMAC_RX_IPG);

	/* enable status header, enable CRC */
	xrx200_pmac_mask(priv, 0,
			 PMAC_HD_CTL_RST | PMAC_HD_CTL_AST | PMAC_HD_CTL_RXSH |
			 PMAC_HD_CTL_AS | PMAC_HD_CTL_AC | PMAC_HD_CTL_RC,
			 PMAC_HD_CTL);

	/* setup NAPI */
	netif_napi_add(net_dev, &priv->chan_rx.napi, xrx200_poll_rx, 32);
	netif_tx_napi_add(net_dev, &priv->chan_tx.napi, xrx200_tx_housekeeping, 32);

	platform_set_drvdata(pdev, priv);

	err = register_netdev(net_dev);
	if (err)
		goto err_unprepare_clk;

	return 0;

err_unprepare_clk:
	clk_disable_unprepare(priv->clk);

err_uninit_dma:
	xrx200_hw_cleanup(priv);

	return err;
}

static int xrx200_remove(struct platform_device *pdev)
{
	struct xrx200_priv *priv = platform_get_drvdata(pdev);
	struct net_device *net_dev = priv->net_dev;

	/* free stack related instances */
	netif_stop_queue(net_dev);
	netif_napi_del(&priv->chan_tx.napi);
	netif_napi_del(&priv->chan_rx.napi);

	/* remove the actual device */
	unregister_netdev(net_dev);

	/* release the clock */
	clk_disable_unprepare(priv->clk);

	/* shut down hardware */
	xrx200_hw_cleanup(priv);

	return 0;
}

static const struct of_device_id xrx200_match[] = {
	{ .compatible = "lantiq,xrx200-net" },
	{},
};
MODULE_DEVICE_TABLE(of, xrx200_match);

static struct platform_driver xrx200_driver = {
	.probe = xrx200_probe,
	.remove = xrx200_remove,
	.driver = {
		.name = "lantiq,xrx200-net",
		.of_match_table = xrx200_match,
	},
};

module_platform_driver(xrx200_driver);

MODULE_AUTHOR("John Crispin <john@phrozen.org>");
MODULE_DESCRIPTION("Lantiq SoC XRX200 ethernet");
MODULE_LICENSE("GPL");