1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Lantiq / Intel PMAC driver for XRX200 SoCs
4  *
5  * Copyright (C) 2010 Lantiq Deutschland
6  * Copyright (C) 2012 John Crispin <john@phrozen.org>
7  * Copyright (C) 2017 - 2018 Hauke Mehrtens <hauke@hauke-m.de>
8  */
9 
10 #include <linux/etherdevice.h>
11 #include <linux/module.h>
12 #include <linux/platform_device.h>
13 #include <linux/interrupt.h>
14 #include <linux/clk.h>
15 #include <linux/delay.h>
16 
17 #include <linux/if_vlan.h>
18 
19 #include <linux/of_net.h>
20 #include <linux/of_platform.h>
21 
22 #include <xway_dma.h>
23 
24 /* DMA */
25 #define XRX200_DMA_DATA_LEN	(SZ_64K - 1)
26 #define XRX200_DMA_RX		0
27 #define XRX200_DMA_TX		1
28 #define XRX200_DMA_BURST_LEN	8
29 
30 #define XRX200_DMA_PACKET_COMPLETE	0
31 #define XRX200_DMA_PACKET_IN_PROGRESS	1
32 
33 /* cpu port mac */
34 #define PMAC_RX_IPG		0x0024
35 #define PMAC_RX_IPG_MASK	0xf
36 
37 #define PMAC_HD_CTL		0x0000
38 /* Add Ethernet header to packets from DMA to PMAC */
39 #define PMAC_HD_CTL_ADD		BIT(0)
40 /* Add VLAN tag to Packets from DMA to PMAC */
41 #define PMAC_HD_CTL_TAG		BIT(1)
42 /* Add CRC to packets from DMA to PMAC */
43 #define PMAC_HD_CTL_AC		BIT(2)
44 /* Add status header to packets from PMAC to DMA */
45 #define PMAC_HD_CTL_AS		BIT(3)
46 /* Remove CRC from packets from PMAC to DMA */
47 #define PMAC_HD_CTL_RC		BIT(4)
48 /* Remove Layer-2 header from packets from PMAC to DMA */
49 #define PMAC_HD_CTL_RL2		BIT(5)
50 /* Status header is present from DMA to PMAC */
51 #define PMAC_HD_CTL_RXSH	BIT(6)
52 /* Add special tag from PMAC to switch */
53 #define PMAC_HD_CTL_AST		BIT(7)
54 /* Remove specail Tag from PMAC to DMA */
55 #define PMAC_HD_CTL_RST		BIT(8)
56 /* Check CRC from DMA to PMAC */
57 #define PMAC_HD_CTL_CCRC	BIT(9)
58 /* Enable reaction to Pause frames in the PMAC */
59 #define PMAC_HD_CTL_FC		BIT(10)
60 
61 struct xrx200_chan {
62 	int tx_free;
63 
64 	struct napi_struct napi;
65 	struct ltq_dma_channel dma;
66 
67 	union {
68 		struct sk_buff *skb[LTQ_DESC_NUM];
69 		void *rx_buff[LTQ_DESC_NUM];
70 	};
71 
72 	struct sk_buff *skb_head;
73 	struct sk_buff *skb_tail;
74 
75 	struct xrx200_priv *priv;
76 };
77 
78 struct xrx200_priv {
79 	struct clk *clk;
80 
81 	struct xrx200_chan chan_tx;
82 	struct xrx200_chan chan_rx;
83 
84 	u16 rx_buf_size;
85 	u16 rx_skb_size;
86 
87 	struct net_device *net_dev;
88 	struct device *dev;
89 
90 	__iomem void *pmac_reg;
91 };
92 
93 static u32 xrx200_pmac_r32(struct xrx200_priv *priv, u32 offset)
94 {
95 	return __raw_readl(priv->pmac_reg + offset);
96 }
97 
98 static void xrx200_pmac_w32(struct xrx200_priv *priv, u32 val, u32 offset)
99 {
100 	__raw_writel(val, priv->pmac_reg + offset);
101 }
102 
103 static void xrx200_pmac_mask(struct xrx200_priv *priv, u32 clear, u32 set,
104 			     u32 offset)
105 {
106 	u32 val = xrx200_pmac_r32(priv, offset);
107 
108 	val &= ~(clear);
109 	val |= set;
110 	xrx200_pmac_w32(priv, val, offset);
111 }
112 
113 static int xrx200_max_frame_len(int mtu)
114 {
115 	return VLAN_ETH_HLEN + mtu;
116 }
117 
118 static int xrx200_buffer_size(int mtu)
119 {
120 	return round_up(xrx200_max_frame_len(mtu), 4 * XRX200_DMA_BURST_LEN);
121 }
122 
123 static int xrx200_skb_size(u16 buf_size)
124 {
125 	return SKB_DATA_ALIGN(buf_size + NET_SKB_PAD + NET_IP_ALIGN) +
126 		SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
127 }
128 
129 /* drop all the packets from the DMA ring */
130 static void xrx200_flush_dma(struct xrx200_chan *ch)
131 {
132 	int i;
133 
134 	for (i = 0; i < LTQ_DESC_NUM; i++) {
135 		struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
136 
137 		if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) != LTQ_DMA_C)
138 			break;
139 
140 		desc->ctl = LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) |
141 			    ch->priv->rx_buf_size;
142 		ch->dma.desc++;
143 		ch->dma.desc %= LTQ_DESC_NUM;
144 	}
145 }
146 
147 static int xrx200_open(struct net_device *net_dev)
148 {
149 	struct xrx200_priv *priv = netdev_priv(net_dev);
150 
151 	napi_enable(&priv->chan_tx.napi);
152 	ltq_dma_open(&priv->chan_tx.dma);
153 	ltq_dma_enable_irq(&priv->chan_tx.dma);
154 
155 	napi_enable(&priv->chan_rx.napi);
156 	ltq_dma_open(&priv->chan_rx.dma);
157 	/* The boot loader does not always deactivate the receiving of frames
158 	 * on the ports and then some packets queue up in the PPE buffers.
159 	 * They already passed the PMAC so they do not have the tags
160 	 * configured here. Read the these packets here and drop them.
161 	 * The HW should have written them into memory after 10us
162 	 */
163 	usleep_range(20, 40);
164 	xrx200_flush_dma(&priv->chan_rx);
165 	ltq_dma_enable_irq(&priv->chan_rx.dma);
166 
167 	netif_wake_queue(net_dev);
168 
169 	return 0;
170 }
171 
172 static int xrx200_close(struct net_device *net_dev)
173 {
174 	struct xrx200_priv *priv = netdev_priv(net_dev);
175 
176 	netif_stop_queue(net_dev);
177 
178 	napi_disable(&priv->chan_rx.napi);
179 	ltq_dma_close(&priv->chan_rx.dma);
180 
181 	napi_disable(&priv->chan_tx.napi);
182 	ltq_dma_close(&priv->chan_tx.dma);
183 
184 	return 0;
185 }
186 
187 static int xrx200_alloc_buf(struct xrx200_chan *ch, void *(*alloc)(unsigned int size))
188 {
189 	void *buf = ch->rx_buff[ch->dma.desc];
190 	struct xrx200_priv *priv = ch->priv;
191 	dma_addr_t mapping;
192 	int ret = 0;
193 
194 	ch->rx_buff[ch->dma.desc] = alloc(priv->rx_skb_size);
195 	if (!ch->rx_buff[ch->dma.desc]) {
196 		ch->rx_buff[ch->dma.desc] = buf;
197 		ret = -ENOMEM;
198 		goto skip;
199 	}
200 
201 	mapping = dma_map_single(priv->dev, ch->rx_buff[ch->dma.desc],
202 				 priv->rx_buf_size, DMA_FROM_DEVICE);
203 	if (unlikely(dma_mapping_error(priv->dev, mapping))) {
204 		skb_free_frag(ch->rx_buff[ch->dma.desc]);
205 		ch->rx_buff[ch->dma.desc] = buf;
206 		ret = -ENOMEM;
207 		goto skip;
208 	}
209 
210 	ch->dma.desc_base[ch->dma.desc].addr = mapping + NET_SKB_PAD + NET_IP_ALIGN;
211 	/* Make sure the address is written before we give it to HW */
212 	wmb();
213 skip:
214 	ch->dma.desc_base[ch->dma.desc].ctl =
215 		LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) | priv->rx_buf_size;
216 
217 	return ret;
218 }
219 
220 static int xrx200_hw_receive(struct xrx200_chan *ch)
221 {
222 	struct xrx200_priv *priv = ch->priv;
223 	struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
224 	void *buf = ch->rx_buff[ch->dma.desc];
225 	u32 ctl = desc->ctl;
226 	int len = (ctl & LTQ_DMA_SIZE_MASK);
227 	struct net_device *net_dev = priv->net_dev;
228 	struct sk_buff *skb;
229 	int ret;
230 
231 	ret = xrx200_alloc_buf(ch, napi_alloc_frag);
232 
233 	ch->dma.desc++;
234 	ch->dma.desc %= LTQ_DESC_NUM;
235 
236 	if (ret) {
237 		net_dev->stats.rx_dropped++;
238 		netdev_err(net_dev, "failed to allocate new rx buffer\n");
239 		return ret;
240 	}
241 
242 	skb = build_skb(buf, priv->rx_skb_size);
243 	if (!skb) {
244 		skb_free_frag(buf);
245 		net_dev->stats.rx_dropped++;
246 		return -ENOMEM;
247 	}
248 
249 	skb_reserve(skb, NET_SKB_PAD);
250 	skb_put(skb, len);
251 
252 	/* add buffers to skb via skb->frag_list */
253 	if (ctl & LTQ_DMA_SOP) {
254 		ch->skb_head = skb;
255 		ch->skb_tail = skb;
256 		skb_reserve(skb, NET_IP_ALIGN);
257 	} else if (ch->skb_head) {
258 		if (ch->skb_head == ch->skb_tail)
259 			skb_shinfo(ch->skb_tail)->frag_list = skb;
260 		else
261 			ch->skb_tail->next = skb;
262 		ch->skb_tail = skb;
263 		ch->skb_head->len += skb->len;
264 		ch->skb_head->data_len += skb->len;
265 		ch->skb_head->truesize += skb->truesize;
266 	}
267 
268 	if (ctl & LTQ_DMA_EOP) {
269 		ch->skb_head->protocol = eth_type_trans(ch->skb_head, net_dev);
270 		net_dev->stats.rx_packets++;
271 		net_dev->stats.rx_bytes += ch->skb_head->len;
272 		netif_receive_skb(ch->skb_head);
273 		ch->skb_head = NULL;
274 		ch->skb_tail = NULL;
275 		ret = XRX200_DMA_PACKET_COMPLETE;
276 	} else {
277 		ret = XRX200_DMA_PACKET_IN_PROGRESS;
278 	}
279 
280 	return ret;
281 }
282 
283 static int xrx200_poll_rx(struct napi_struct *napi, int budget)
284 {
285 	struct xrx200_chan *ch = container_of(napi,
286 				struct xrx200_chan, napi);
287 	int rx = 0;
288 	int ret;
289 
290 	while (rx < budget) {
291 		struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
292 
293 		if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) == LTQ_DMA_C) {
294 			ret = xrx200_hw_receive(ch);
295 			if (ret == XRX200_DMA_PACKET_IN_PROGRESS)
296 				continue;
297 			if (ret != XRX200_DMA_PACKET_COMPLETE)
298 				break;
299 			rx++;
300 		} else {
301 			break;
302 		}
303 	}
304 
305 	if (rx < budget) {
306 		if (napi_complete_done(&ch->napi, rx))
307 			ltq_dma_enable_irq(&ch->dma);
308 	}
309 
310 	return rx;
311 }
312 
313 static int xrx200_tx_housekeeping(struct napi_struct *napi, int budget)
314 {
315 	struct xrx200_chan *ch = container_of(napi,
316 				struct xrx200_chan, napi);
317 	struct net_device *net_dev = ch->priv->net_dev;
318 	int pkts = 0;
319 	int bytes = 0;
320 
321 	netif_tx_lock(net_dev);
322 	while (pkts < budget) {
323 		struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->tx_free];
324 
325 		if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) == LTQ_DMA_C) {
326 			struct sk_buff *skb = ch->skb[ch->tx_free];
327 
328 			pkts++;
329 			bytes += skb->len;
330 			ch->skb[ch->tx_free] = NULL;
331 			consume_skb(skb);
332 			memset(&ch->dma.desc_base[ch->tx_free], 0,
333 			       sizeof(struct ltq_dma_desc));
334 			ch->tx_free++;
335 			ch->tx_free %= LTQ_DESC_NUM;
336 		} else {
337 			break;
338 		}
339 	}
340 
341 	net_dev->stats.tx_packets += pkts;
342 	net_dev->stats.tx_bytes += bytes;
343 	netdev_completed_queue(ch->priv->net_dev, pkts, bytes);
344 
345 	netif_tx_unlock(net_dev);
346 	if (netif_queue_stopped(net_dev))
347 		netif_wake_queue(net_dev);
348 
349 	if (pkts < budget) {
350 		if (napi_complete_done(&ch->napi, pkts))
351 			ltq_dma_enable_irq(&ch->dma);
352 	}
353 
354 	return pkts;
355 }
356 
357 static netdev_tx_t xrx200_start_xmit(struct sk_buff *skb,
358 				     struct net_device *net_dev)
359 {
360 	struct xrx200_priv *priv = netdev_priv(net_dev);
361 	struct xrx200_chan *ch = &priv->chan_tx;
362 	struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
363 	u32 byte_offset;
364 	dma_addr_t mapping;
365 	int len;
366 
367 	skb->dev = net_dev;
368 	if (skb_put_padto(skb, ETH_ZLEN)) {
369 		net_dev->stats.tx_dropped++;
370 		return NETDEV_TX_OK;
371 	}
372 
373 	len = skb->len;
374 
375 	if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) || ch->skb[ch->dma.desc]) {
376 		netdev_err(net_dev, "tx ring full\n");
377 		netif_stop_queue(net_dev);
378 		return NETDEV_TX_BUSY;
379 	}
380 
381 	ch->skb[ch->dma.desc] = skb;
382 
383 	mapping = dma_map_single(priv->dev, skb->data, len, DMA_TO_DEVICE);
384 	if (unlikely(dma_mapping_error(priv->dev, mapping)))
385 		goto err_drop;
386 
387 	/* dma needs to start on a burst length value aligned address */
388 	byte_offset = mapping % (XRX200_DMA_BURST_LEN * 4);
389 
390 	desc->addr = mapping - byte_offset;
391 	/* Make sure the address is written before we give it to HW */
392 	wmb();
393 	desc->ctl = LTQ_DMA_OWN | LTQ_DMA_SOP | LTQ_DMA_EOP |
394 		LTQ_DMA_TX_OFFSET(byte_offset) | (len & LTQ_DMA_SIZE_MASK);
395 	ch->dma.desc++;
396 	ch->dma.desc %= LTQ_DESC_NUM;
397 	if (ch->dma.desc == ch->tx_free)
398 		netif_stop_queue(net_dev);
399 
400 	netdev_sent_queue(net_dev, len);
401 
402 	return NETDEV_TX_OK;
403 
404 err_drop:
405 	dev_kfree_skb(skb);
406 	net_dev->stats.tx_dropped++;
407 	net_dev->stats.tx_errors++;
408 	return NETDEV_TX_OK;
409 }
410 
411 static int
412 xrx200_change_mtu(struct net_device *net_dev, int new_mtu)
413 {
414 	struct xrx200_priv *priv = netdev_priv(net_dev);
415 	struct xrx200_chan *ch_rx = &priv->chan_rx;
416 	int old_mtu = net_dev->mtu;
417 	bool running = false;
418 	void *buff;
419 	int curr_desc;
420 	int ret = 0;
421 
422 	net_dev->mtu = new_mtu;
423 	priv->rx_buf_size = xrx200_buffer_size(new_mtu);
424 	priv->rx_skb_size = xrx200_skb_size(priv->rx_buf_size);
425 
426 	if (new_mtu <= old_mtu)
427 		return ret;
428 
429 	running = netif_running(net_dev);
430 	if (running) {
431 		napi_disable(&ch_rx->napi);
432 		ltq_dma_close(&ch_rx->dma);
433 	}
434 
435 	xrx200_poll_rx(&ch_rx->napi, LTQ_DESC_NUM);
436 	curr_desc = ch_rx->dma.desc;
437 
438 	for (ch_rx->dma.desc = 0; ch_rx->dma.desc < LTQ_DESC_NUM;
439 	     ch_rx->dma.desc++) {
440 		buff = ch_rx->rx_buff[ch_rx->dma.desc];
441 		ret = xrx200_alloc_buf(ch_rx, netdev_alloc_frag);
442 		if (ret) {
443 			net_dev->mtu = old_mtu;
444 			priv->rx_buf_size = xrx200_buffer_size(old_mtu);
445 			priv->rx_skb_size = xrx200_skb_size(priv->rx_buf_size);
446 			break;
447 		}
448 		skb_free_frag(buff);
449 	}
450 
451 	ch_rx->dma.desc = curr_desc;
452 	if (running) {
453 		napi_enable(&ch_rx->napi);
454 		ltq_dma_open(&ch_rx->dma);
455 		ltq_dma_enable_irq(&ch_rx->dma);
456 	}
457 
458 	return ret;
459 }
460 
461 static const struct net_device_ops xrx200_netdev_ops = {
462 	.ndo_open		= xrx200_open,
463 	.ndo_stop		= xrx200_close,
464 	.ndo_start_xmit		= xrx200_start_xmit,
465 	.ndo_change_mtu		= xrx200_change_mtu,
466 	.ndo_set_mac_address	= eth_mac_addr,
467 	.ndo_validate_addr	= eth_validate_addr,
468 };
469 
470 static irqreturn_t xrx200_dma_irq(int irq, void *ptr)
471 {
472 	struct xrx200_chan *ch = ptr;
473 
474 	if (napi_schedule_prep(&ch->napi)) {
475 		ltq_dma_disable_irq(&ch->dma);
476 		__napi_schedule(&ch->napi);
477 	}
478 
479 	ltq_dma_ack_irq(&ch->dma);
480 
481 	return IRQ_HANDLED;
482 }
483 
484 static int xrx200_dma_init(struct xrx200_priv *priv)
485 {
486 	struct xrx200_chan *ch_rx = &priv->chan_rx;
487 	struct xrx200_chan *ch_tx = &priv->chan_tx;
488 	int ret = 0;
489 	int i;
490 
491 	ltq_dma_init_port(DMA_PORT_ETOP, XRX200_DMA_BURST_LEN,
492 			  XRX200_DMA_BURST_LEN);
493 
494 	ch_rx->dma.nr = XRX200_DMA_RX;
495 	ch_rx->dma.dev = priv->dev;
496 	ch_rx->priv = priv;
497 
498 	ltq_dma_alloc_rx(&ch_rx->dma);
499 	for (ch_rx->dma.desc = 0; ch_rx->dma.desc < LTQ_DESC_NUM;
500 	     ch_rx->dma.desc++) {
501 		ret = xrx200_alloc_buf(ch_rx, netdev_alloc_frag);
502 		if (ret)
503 			goto rx_free;
504 	}
505 	ch_rx->dma.desc = 0;
506 	ret = devm_request_irq(priv->dev, ch_rx->dma.irq, xrx200_dma_irq, 0,
507 			       "xrx200_net_rx", &priv->chan_rx);
508 	if (ret) {
509 		dev_err(priv->dev, "failed to request RX irq %d\n",
510 			ch_rx->dma.irq);
511 		goto rx_ring_free;
512 	}
513 
514 	ch_tx->dma.nr = XRX200_DMA_TX;
515 	ch_tx->dma.dev = priv->dev;
516 	ch_tx->priv = priv;
517 
518 	ltq_dma_alloc_tx(&ch_tx->dma);
519 	ret = devm_request_irq(priv->dev, ch_tx->dma.irq, xrx200_dma_irq, 0,
520 			       "xrx200_net_tx", &priv->chan_tx);
521 	if (ret) {
522 		dev_err(priv->dev, "failed to request TX irq %d\n",
523 			ch_tx->dma.irq);
524 		goto tx_free;
525 	}
526 
527 	return ret;
528 
529 tx_free:
530 	ltq_dma_free(&ch_tx->dma);
531 
532 rx_ring_free:
533 	/* free the allocated RX ring */
534 	for (i = 0; i < LTQ_DESC_NUM; i++) {
535 		if (priv->chan_rx.skb[i])
536 			skb_free_frag(priv->chan_rx.rx_buff[i]);
537 	}
538 
539 rx_free:
540 	ltq_dma_free(&ch_rx->dma);
541 	return ret;
542 }
543 
544 static void xrx200_hw_cleanup(struct xrx200_priv *priv)
545 {
546 	int i;
547 
548 	ltq_dma_free(&priv->chan_tx.dma);
549 	ltq_dma_free(&priv->chan_rx.dma);
550 
551 	/* free the allocated RX ring */
552 	for (i = 0; i < LTQ_DESC_NUM; i++)
553 		skb_free_frag(priv->chan_rx.rx_buff[i]);
554 }
555 
556 static int xrx200_probe(struct platform_device *pdev)
557 {
558 	struct device *dev = &pdev->dev;
559 	struct device_node *np = dev->of_node;
560 	struct xrx200_priv *priv;
561 	struct net_device *net_dev;
562 	int err;
563 
564 	/* alloc the network device */
565 	net_dev = devm_alloc_etherdev(dev, sizeof(struct xrx200_priv));
566 	if (!net_dev)
567 		return -ENOMEM;
568 
569 	priv = netdev_priv(net_dev);
570 	priv->net_dev = net_dev;
571 	priv->dev = dev;
572 
573 	net_dev->netdev_ops = &xrx200_netdev_ops;
574 	SET_NETDEV_DEV(net_dev, dev);
575 	net_dev->min_mtu = ETH_ZLEN;
576 	net_dev->max_mtu = XRX200_DMA_DATA_LEN - xrx200_max_frame_len(0);
577 	priv->rx_buf_size = xrx200_buffer_size(ETH_DATA_LEN);
578 	priv->rx_skb_size = xrx200_skb_size(priv->rx_buf_size);
579 
580 	/* load the memory ranges */
581 	priv->pmac_reg = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
582 	if (IS_ERR(priv->pmac_reg))
583 		return PTR_ERR(priv->pmac_reg);
584 
585 	priv->chan_rx.dma.irq = platform_get_irq_byname(pdev, "rx");
586 	if (priv->chan_rx.dma.irq < 0)
587 		return -ENOENT;
588 	priv->chan_tx.dma.irq = platform_get_irq_byname(pdev, "tx");
589 	if (priv->chan_tx.dma.irq < 0)
590 		return -ENOENT;
591 
592 	/* get the clock */
593 	priv->clk = devm_clk_get(dev, NULL);
594 	if (IS_ERR(priv->clk)) {
595 		dev_err(dev, "failed to get clock\n");
596 		return PTR_ERR(priv->clk);
597 	}
598 
599 	err = of_get_ethdev_address(np, net_dev);
600 	if (err)
601 		eth_hw_addr_random(net_dev);
602 
603 	/* bring up the dma engine and IP core */
604 	err = xrx200_dma_init(priv);
605 	if (err)
606 		return err;
607 
608 	/* enable clock gate */
609 	err = clk_prepare_enable(priv->clk);
610 	if (err)
611 		goto err_uninit_dma;
612 
613 	/* set IPG to 12 */
614 	xrx200_pmac_mask(priv, PMAC_RX_IPG_MASK, 0xb, PMAC_RX_IPG);
615 
616 	/* enable status header, enable CRC */
617 	xrx200_pmac_mask(priv, 0,
618 			 PMAC_HD_CTL_RST | PMAC_HD_CTL_AST | PMAC_HD_CTL_RXSH |
619 			 PMAC_HD_CTL_AS | PMAC_HD_CTL_AC | PMAC_HD_CTL_RC,
620 			 PMAC_HD_CTL);
621 
622 	/* setup NAPI */
623 	netif_napi_add(net_dev, &priv->chan_rx.napi, xrx200_poll_rx,
624 		       NAPI_POLL_WEIGHT);
625 	netif_napi_add_tx(net_dev, &priv->chan_tx.napi,
626 			  xrx200_tx_housekeeping);
627 
628 	platform_set_drvdata(pdev, priv);
629 
630 	err = register_netdev(net_dev);
631 	if (err)
632 		goto err_unprepare_clk;
633 
634 	return 0;
635 
636 err_unprepare_clk:
637 	clk_disable_unprepare(priv->clk);
638 
639 err_uninit_dma:
640 	xrx200_hw_cleanup(priv);
641 
642 	return err;
643 }
644 
645 static int xrx200_remove(struct platform_device *pdev)
646 {
647 	struct xrx200_priv *priv = platform_get_drvdata(pdev);
648 	struct net_device *net_dev = priv->net_dev;
649 
650 	/* free stack related instances */
651 	netif_stop_queue(net_dev);
652 	netif_napi_del(&priv->chan_tx.napi);
653 	netif_napi_del(&priv->chan_rx.napi);
654 
655 	/* remove the actual device */
656 	unregister_netdev(net_dev);
657 
658 	/* release the clock */
659 	clk_disable_unprepare(priv->clk);
660 
661 	/* shut down hardware */
662 	xrx200_hw_cleanup(priv);
663 
664 	return 0;
665 }
666 
667 static const struct of_device_id xrx200_match[] = {
668 	{ .compatible = "lantiq,xrx200-net" },
669 	{},
670 };
671 MODULE_DEVICE_TABLE(of, xrx200_match);
672 
673 static struct platform_driver xrx200_driver = {
674 	.probe = xrx200_probe,
675 	.remove = xrx200_remove,
676 	.driver = {
677 		.name = "lantiq,xrx200-net",
678 		.of_match_table = xrx200_match,
679 	},
680 };
681 
682 module_platform_driver(xrx200_driver);
683 
684 MODULE_AUTHOR("John Crispin <john@phrozen.org>");
685 MODULE_DESCRIPTION("Lantiq SoC XRX200 ethernet");
686 MODULE_LICENSE("GPL");
687