1 /* MOXA ART Ethernet (RTL8201CP) driver.
2  *
3  * Copyright (C) 2013 Jonas Jensen
4  *
5  * Jonas Jensen <jonas.jensen@gmail.com>
6  *
7  * Based on code from
8  * Moxa Technology Co., Ltd. <www.moxa.com>
9  *
10  * This file is licensed under the terms of the GNU General Public
11  * License version 2.  This program is licensed "as is" without any
12  * warranty of any kind, whether express or implied.
13  */
14 
15 #include <linux/module.h>
16 #include <linux/netdevice.h>
17 #include <linux/etherdevice.h>
18 #include <linux/skbuff.h>
19 #include <linux/dma-mapping.h>
20 #include <linux/ethtool.h>
21 #include <linux/platform_device.h>
22 #include <linux/interrupt.h>
23 #include <linux/irq.h>
24 #include <linux/of_address.h>
25 #include <linux/of_irq.h>
26 #include <linux/crc32.h>
27 #include <linux/crc32c.h>
28 
29 #include "moxart_ether.h"
30 
31 static inline void moxart_desc_write(u32 data, u32 *desc)
32 {
33 	*desc = cpu_to_le32(data);
34 }
35 
36 static inline u32 moxart_desc_read(u32 *desc)
37 {
38 	return le32_to_cpu(*desc);
39 }
40 
41 static inline void moxart_emac_write(struct net_device *ndev,
42 				     unsigned int reg, unsigned long value)
43 {
44 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
45 
46 	writel(value, priv->base + reg);
47 }
48 
49 static void moxart_update_mac_address(struct net_device *ndev)
50 {
51 	moxart_emac_write(ndev, REG_MAC_MS_ADDRESS,
52 			  ((ndev->dev_addr[0] << 8) | (ndev->dev_addr[1])));
53 	moxart_emac_write(ndev, REG_MAC_MS_ADDRESS + 4,
54 			  ((ndev->dev_addr[2] << 24) |
55 			   (ndev->dev_addr[3] << 16) |
56 			   (ndev->dev_addr[4] << 8) |
57 			   (ndev->dev_addr[5])));
58 }
59 
60 static int moxart_set_mac_address(struct net_device *ndev, void *addr)
61 {
62 	struct sockaddr *address = addr;
63 
64 	if (!is_valid_ether_addr(address->sa_data))
65 		return -EADDRNOTAVAIL;
66 
67 	memcpy(ndev->dev_addr, address->sa_data, ndev->addr_len);
68 	moxart_update_mac_address(ndev);
69 
70 	return 0;
71 }
72 
73 static void moxart_mac_free_memory(struct net_device *ndev)
74 {
75 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
76 	int i;
77 
78 	for (i = 0; i < RX_DESC_NUM; i++)
79 		dma_unmap_single(&ndev->dev, priv->rx_mapping[i],
80 				 priv->rx_buf_size, DMA_FROM_DEVICE);
81 
82 	if (priv->tx_desc_base)
83 		dma_free_coherent(NULL, TX_REG_DESC_SIZE * TX_DESC_NUM,
84 				  priv->tx_desc_base, priv->tx_base);
85 
86 	if (priv->rx_desc_base)
87 		dma_free_coherent(NULL, RX_REG_DESC_SIZE * RX_DESC_NUM,
88 				  priv->rx_desc_base, priv->rx_base);
89 
90 	kfree(priv->tx_buf_base);
91 	kfree(priv->rx_buf_base);
92 }
93 
94 static void moxart_mac_reset(struct net_device *ndev)
95 {
96 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
97 
98 	writel(SW_RST, priv->base + REG_MAC_CTRL);
99 	while (readl(priv->base + REG_MAC_CTRL) & SW_RST)
100 		mdelay(10);
101 
102 	writel(0, priv->base + REG_INTERRUPT_MASK);
103 
104 	priv->reg_maccr = RX_BROADPKT | FULLDUP | CRC_APD | RX_FTL;
105 }
106 
107 static void moxart_mac_enable(struct net_device *ndev)
108 {
109 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
110 
111 	writel(0x00001010, priv->base + REG_INT_TIMER_CTRL);
112 	writel(0x00000001, priv->base + REG_APOLL_TIMER_CTRL);
113 	writel(0x00000390, priv->base + REG_DMA_BLEN_CTRL);
114 
115 	priv->reg_imr |= (RPKT_FINISH_M | XPKT_FINISH_M);
116 	writel(priv->reg_imr, priv->base + REG_INTERRUPT_MASK);
117 
118 	priv->reg_maccr |= (RCV_EN | XMT_EN | RDMA_EN | XDMA_EN);
119 	writel(priv->reg_maccr, priv->base + REG_MAC_CTRL);
120 }
121 
122 static void moxart_mac_setup_desc_ring(struct net_device *ndev)
123 {
124 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
125 	void *desc;
126 	int i;
127 
128 	for (i = 0; i < TX_DESC_NUM; i++) {
129 		desc = priv->tx_desc_base + i * TX_REG_DESC_SIZE;
130 		memset(desc, 0, TX_REG_DESC_SIZE);
131 
132 		priv->tx_buf[i] = priv->tx_buf_base + priv->tx_buf_size * i;
133 	}
134 	moxart_desc_write(TX_DESC1_END, desc + TX_REG_OFFSET_DESC1);
135 
136 	priv->tx_head = 0;
137 	priv->tx_tail = 0;
138 
139 	for (i = 0; i < RX_DESC_NUM; i++) {
140 		desc = priv->rx_desc_base + i * RX_REG_DESC_SIZE;
141 		memset(desc, 0, RX_REG_DESC_SIZE);
142 		moxart_desc_write(RX_DESC0_DMA_OWN, desc + RX_REG_OFFSET_DESC0);
143 		moxart_desc_write(RX_BUF_SIZE & RX_DESC1_BUF_SIZE_MASK,
144 		       desc + RX_REG_OFFSET_DESC1);
145 
146 		priv->rx_buf[i] = priv->rx_buf_base + priv->rx_buf_size * i;
147 		priv->rx_mapping[i] = dma_map_single(&ndev->dev,
148 						     priv->rx_buf[i],
149 						     priv->rx_buf_size,
150 						     DMA_FROM_DEVICE);
151 		if (dma_mapping_error(&ndev->dev, priv->rx_mapping[i]))
152 			netdev_err(ndev, "DMA mapping error\n");
153 
154 		moxart_desc_write(priv->rx_mapping[i],
155 		       desc + RX_REG_OFFSET_DESC2 + RX_DESC2_ADDRESS_PHYS);
156 		moxart_desc_write((uintptr_t)priv->rx_buf[i],
157 		       desc + RX_REG_OFFSET_DESC2 + RX_DESC2_ADDRESS_VIRT);
158 	}
159 	moxart_desc_write(RX_DESC1_END, desc + RX_REG_OFFSET_DESC1);
160 
161 	priv->rx_head = 0;
162 
163 	/* reset the MAC controller TX/RX desciptor base address */
164 	writel(priv->tx_base, priv->base + REG_TXR_BASE_ADDRESS);
165 	writel(priv->rx_base, priv->base + REG_RXR_BASE_ADDRESS);
166 }
167 
168 static int moxart_mac_open(struct net_device *ndev)
169 {
170 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
171 
172 	if (!is_valid_ether_addr(ndev->dev_addr))
173 		return -EADDRNOTAVAIL;
174 
175 	napi_enable(&priv->napi);
176 
177 	moxart_mac_reset(ndev);
178 	moxart_update_mac_address(ndev);
179 	moxart_mac_setup_desc_ring(ndev);
180 	moxart_mac_enable(ndev);
181 	netif_start_queue(ndev);
182 
183 	netdev_dbg(ndev, "%s: IMR=0x%x, MACCR=0x%x\n",
184 		   __func__, readl(priv->base + REG_INTERRUPT_MASK),
185 		   readl(priv->base + REG_MAC_CTRL));
186 
187 	return 0;
188 }
189 
190 static int moxart_mac_stop(struct net_device *ndev)
191 {
192 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
193 
194 	napi_disable(&priv->napi);
195 
196 	netif_stop_queue(ndev);
197 
198 	/* disable all interrupts */
199 	writel(0, priv->base + REG_INTERRUPT_MASK);
200 
201 	/* disable all functions */
202 	writel(0, priv->base + REG_MAC_CTRL);
203 
204 	return 0;
205 }
206 
207 static int moxart_rx_poll(struct napi_struct *napi, int budget)
208 {
209 	struct moxart_mac_priv_t *priv = container_of(napi,
210 						      struct moxart_mac_priv_t,
211 						      napi);
212 	struct net_device *ndev = priv->ndev;
213 	struct sk_buff *skb;
214 	void *desc;
215 	unsigned int desc0, len;
216 	int rx_head = priv->rx_head;
217 	int rx = 0;
218 
219 	while (rx < budget) {
220 		desc = priv->rx_desc_base + (RX_REG_DESC_SIZE * rx_head);
221 		desc0 = moxart_desc_read(desc + RX_REG_OFFSET_DESC0);
222 		rmb(); /* ensure desc0 is up to date */
223 
224 		if (desc0 & RX_DESC0_DMA_OWN)
225 			break;
226 
227 		if (desc0 & (RX_DESC0_ERR | RX_DESC0_CRC_ERR | RX_DESC0_FTL |
228 			     RX_DESC0_RUNT | RX_DESC0_ODD_NB)) {
229 			net_dbg_ratelimited("packet error\n");
230 			priv->stats.rx_dropped++;
231 			priv->stats.rx_errors++;
232 			goto rx_next;
233 		}
234 
235 		len = desc0 & RX_DESC0_FRAME_LEN_MASK;
236 
237 		if (len > RX_BUF_SIZE)
238 			len = RX_BUF_SIZE;
239 
240 		dma_sync_single_for_cpu(&ndev->dev,
241 					priv->rx_mapping[rx_head],
242 					priv->rx_buf_size, DMA_FROM_DEVICE);
243 		skb = netdev_alloc_skb_ip_align(ndev, len);
244 
245 		if (unlikely(!skb)) {
246 			net_dbg_ratelimited("netdev_alloc_skb_ip_align failed\n");
247 			priv->stats.rx_dropped++;
248 			priv->stats.rx_errors++;
249 			goto rx_next;
250 		}
251 
252 		memcpy(skb->data, priv->rx_buf[rx_head], len);
253 		skb_put(skb, len);
254 		skb->protocol = eth_type_trans(skb, ndev);
255 		napi_gro_receive(&priv->napi, skb);
256 		rx++;
257 
258 		priv->stats.rx_packets++;
259 		priv->stats.rx_bytes += len;
260 		if (desc0 & RX_DESC0_MULTICAST)
261 			priv->stats.multicast++;
262 
263 rx_next:
264 		wmb(); /* prevent setting ownership back too early */
265 		moxart_desc_write(RX_DESC0_DMA_OWN, desc + RX_REG_OFFSET_DESC0);
266 
267 		rx_head = RX_NEXT(rx_head);
268 		priv->rx_head = rx_head;
269 	}
270 
271 	if (rx < budget) {
272 		napi_complete(napi);
273 	}
274 
275 	priv->reg_imr |= RPKT_FINISH_M;
276 	writel(priv->reg_imr, priv->base + REG_INTERRUPT_MASK);
277 
278 	return rx;
279 }
280 
281 static void moxart_tx_finished(struct net_device *ndev)
282 {
283 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
284 	unsigned tx_head = priv->tx_head;
285 	unsigned tx_tail = priv->tx_tail;
286 
287 	while (tx_tail != tx_head) {
288 		dma_unmap_single(&ndev->dev, priv->tx_mapping[tx_tail],
289 				 priv->tx_len[tx_tail], DMA_TO_DEVICE);
290 
291 		priv->stats.tx_packets++;
292 		priv->stats.tx_bytes += priv->tx_skb[tx_tail]->len;
293 
294 		dev_kfree_skb_irq(priv->tx_skb[tx_tail]);
295 		priv->tx_skb[tx_tail] = NULL;
296 
297 		tx_tail = TX_NEXT(tx_tail);
298 	}
299 	priv->tx_tail = tx_tail;
300 }
301 
302 static irqreturn_t moxart_mac_interrupt(int irq, void *dev_id)
303 {
304 	struct net_device *ndev = (struct net_device *) dev_id;
305 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
306 	unsigned int ists = readl(priv->base + REG_INTERRUPT_STATUS);
307 
308 	if (ists & XPKT_OK_INT_STS)
309 		moxart_tx_finished(ndev);
310 
311 	if (ists & RPKT_FINISH) {
312 		if (napi_schedule_prep(&priv->napi)) {
313 			priv->reg_imr &= ~RPKT_FINISH_M;
314 			writel(priv->reg_imr, priv->base + REG_INTERRUPT_MASK);
315 			__napi_schedule(&priv->napi);
316 		}
317 	}
318 
319 	return IRQ_HANDLED;
320 }
321 
322 static int moxart_mac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
323 {
324 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
325 	void *desc;
326 	unsigned int len;
327 	unsigned int tx_head = priv->tx_head;
328 	u32 txdes1;
329 	int ret = NETDEV_TX_BUSY;
330 
331 	desc = priv->tx_desc_base + (TX_REG_DESC_SIZE * tx_head);
332 
333 	spin_lock_irq(&priv->txlock);
334 	if (moxart_desc_read(desc + TX_REG_OFFSET_DESC0) & TX_DESC0_DMA_OWN) {
335 		net_dbg_ratelimited("no TX space for packet\n");
336 		priv->stats.tx_dropped++;
337 		goto out_unlock;
338 	}
339 	rmb(); /* ensure data is only read that had TX_DESC0_DMA_OWN cleared */
340 
341 	len = skb->len > TX_BUF_SIZE ? TX_BUF_SIZE : skb->len;
342 
343 	priv->tx_mapping[tx_head] = dma_map_single(&ndev->dev, skb->data,
344 						   len, DMA_TO_DEVICE);
345 	if (dma_mapping_error(&ndev->dev, priv->tx_mapping[tx_head])) {
346 		netdev_err(ndev, "DMA mapping error\n");
347 		goto out_unlock;
348 	}
349 
350 	priv->tx_len[tx_head] = len;
351 	priv->tx_skb[tx_head] = skb;
352 
353 	moxart_desc_write(priv->tx_mapping[tx_head],
354 	       desc + TX_REG_OFFSET_DESC2 + TX_DESC2_ADDRESS_PHYS);
355 	moxart_desc_write((uintptr_t)skb->data,
356 	       desc + TX_REG_OFFSET_DESC2 + TX_DESC2_ADDRESS_VIRT);
357 
358 	if (skb->len < ETH_ZLEN) {
359 		memset(&skb->data[skb->len],
360 		       0, ETH_ZLEN - skb->len);
361 		len = ETH_ZLEN;
362 	}
363 
364 	dma_sync_single_for_device(&ndev->dev, priv->tx_mapping[tx_head],
365 				   priv->tx_buf_size, DMA_TO_DEVICE);
366 
367 	txdes1 = TX_DESC1_LTS | TX_DESC1_FTS | (len & TX_DESC1_BUF_SIZE_MASK);
368 	if (tx_head == TX_DESC_NUM_MASK)
369 		txdes1 |= TX_DESC1_END;
370 	moxart_desc_write(txdes1, desc + TX_REG_OFFSET_DESC1);
371 	wmb(); /* flush descriptor before transferring ownership */
372 	moxart_desc_write(TX_DESC0_DMA_OWN, desc + TX_REG_OFFSET_DESC0);
373 
374 	/* start to send packet */
375 	writel(0xffffffff, priv->base + REG_TX_POLL_DEMAND);
376 
377 	priv->tx_head = TX_NEXT(tx_head);
378 
379 	netif_trans_update(ndev);
380 	ret = NETDEV_TX_OK;
381 out_unlock:
382 	spin_unlock_irq(&priv->txlock);
383 
384 	return ret;
385 }
386 
387 static struct net_device_stats *moxart_mac_get_stats(struct net_device *ndev)
388 {
389 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
390 
391 	return &priv->stats;
392 }
393 
394 static void moxart_mac_setmulticast(struct net_device *ndev)
395 {
396 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
397 	struct netdev_hw_addr *ha;
398 	int crc_val;
399 
400 	netdev_for_each_mc_addr(ha, ndev) {
401 		crc_val = crc32_le(~0, ha->addr, ETH_ALEN);
402 		crc_val = (crc_val >> 26) & 0x3f;
403 		if (crc_val >= 32) {
404 			writel(readl(priv->base + REG_MCAST_HASH_TABLE1) |
405 			       (1UL << (crc_val - 32)),
406 			       priv->base + REG_MCAST_HASH_TABLE1);
407 		} else {
408 			writel(readl(priv->base + REG_MCAST_HASH_TABLE0) |
409 			       (1UL << crc_val),
410 			       priv->base + REG_MCAST_HASH_TABLE0);
411 		}
412 	}
413 }
414 
415 static void moxart_mac_set_rx_mode(struct net_device *ndev)
416 {
417 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
418 
419 	spin_lock_irq(&priv->txlock);
420 
421 	(ndev->flags & IFF_PROMISC) ? (priv->reg_maccr |= RCV_ALL) :
422 				      (priv->reg_maccr &= ~RCV_ALL);
423 
424 	(ndev->flags & IFF_ALLMULTI) ? (priv->reg_maccr |= RX_MULTIPKT) :
425 				       (priv->reg_maccr &= ~RX_MULTIPKT);
426 
427 	if ((ndev->flags & IFF_MULTICAST) && netdev_mc_count(ndev)) {
428 		priv->reg_maccr |= HT_MULTI_EN;
429 		moxart_mac_setmulticast(ndev);
430 	} else {
431 		priv->reg_maccr &= ~HT_MULTI_EN;
432 	}
433 
434 	writel(priv->reg_maccr, priv->base + REG_MAC_CTRL);
435 
436 	spin_unlock_irq(&priv->txlock);
437 }
438 
439 static struct net_device_ops moxart_netdev_ops = {
440 	.ndo_open		= moxart_mac_open,
441 	.ndo_stop		= moxart_mac_stop,
442 	.ndo_start_xmit		= moxart_mac_start_xmit,
443 	.ndo_get_stats		= moxart_mac_get_stats,
444 	.ndo_set_rx_mode	= moxart_mac_set_rx_mode,
445 	.ndo_set_mac_address	= moxart_set_mac_address,
446 	.ndo_validate_addr	= eth_validate_addr,
447 	.ndo_change_mtu		= eth_change_mtu,
448 };
449 
450 static int moxart_mac_probe(struct platform_device *pdev)
451 {
452 	struct device *p_dev = &pdev->dev;
453 	struct device_node *node = p_dev->of_node;
454 	struct net_device *ndev;
455 	struct moxart_mac_priv_t *priv;
456 	struct resource *res;
457 	unsigned int irq;
458 	int ret;
459 
460 	ndev = alloc_etherdev(sizeof(struct moxart_mac_priv_t));
461 	if (!ndev)
462 		return -ENOMEM;
463 
464 	irq = irq_of_parse_and_map(node, 0);
465 	if (irq <= 0) {
466 		netdev_err(ndev, "irq_of_parse_and_map failed\n");
467 		ret = -EINVAL;
468 		goto irq_map_fail;
469 	}
470 
471 	priv = netdev_priv(ndev);
472 	priv->ndev = ndev;
473 
474 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
475 	ndev->base_addr = res->start;
476 	priv->base = devm_ioremap_resource(p_dev, res);
477 	if (IS_ERR(priv->base)) {
478 		dev_err(p_dev, "devm_ioremap_resource failed\n");
479 		ret = PTR_ERR(priv->base);
480 		goto init_fail;
481 	}
482 
483 	spin_lock_init(&priv->txlock);
484 
485 	priv->tx_buf_size = TX_BUF_SIZE;
486 	priv->rx_buf_size = RX_BUF_SIZE;
487 
488 	priv->tx_desc_base = dma_alloc_coherent(NULL, TX_REG_DESC_SIZE *
489 						TX_DESC_NUM, &priv->tx_base,
490 						GFP_DMA | GFP_KERNEL);
491 	if (priv->tx_desc_base == NULL) {
492 		ret = -ENOMEM;
493 		goto init_fail;
494 	}
495 
496 	priv->rx_desc_base = dma_alloc_coherent(NULL, RX_REG_DESC_SIZE *
497 						RX_DESC_NUM, &priv->rx_base,
498 						GFP_DMA | GFP_KERNEL);
499 	if (priv->rx_desc_base == NULL) {
500 		ret = -ENOMEM;
501 		goto init_fail;
502 	}
503 
504 	priv->tx_buf_base = kmalloc(priv->tx_buf_size * TX_DESC_NUM,
505 				    GFP_ATOMIC);
506 	if (!priv->tx_buf_base) {
507 		ret = -ENOMEM;
508 		goto init_fail;
509 	}
510 
511 	priv->rx_buf_base = kmalloc(priv->rx_buf_size * RX_DESC_NUM,
512 				    GFP_ATOMIC);
513 	if (!priv->rx_buf_base) {
514 		ret = -ENOMEM;
515 		goto init_fail;
516 	}
517 
518 	platform_set_drvdata(pdev, ndev);
519 
520 	ret = devm_request_irq(p_dev, irq, moxart_mac_interrupt, 0,
521 			       pdev->name, ndev);
522 	if (ret) {
523 		netdev_err(ndev, "devm_request_irq failed\n");
524 		goto init_fail;
525 	}
526 
527 	ndev->netdev_ops = &moxart_netdev_ops;
528 	netif_napi_add(ndev, &priv->napi, moxart_rx_poll, RX_DESC_NUM);
529 	ndev->priv_flags |= IFF_UNICAST_FLT;
530 	ndev->irq = irq;
531 
532 	SET_NETDEV_DEV(ndev, &pdev->dev);
533 
534 	ret = register_netdev(ndev);
535 	if (ret) {
536 		free_netdev(ndev);
537 		goto init_fail;
538 	}
539 
540 	netdev_dbg(ndev, "%s: IRQ=%d address=%pM\n",
541 		   __func__, ndev->irq, ndev->dev_addr);
542 
543 	return 0;
544 
545 init_fail:
546 	netdev_err(ndev, "init failed\n");
547 	moxart_mac_free_memory(ndev);
548 irq_map_fail:
549 	free_netdev(ndev);
550 	return ret;
551 }
552 
553 static int moxart_remove(struct platform_device *pdev)
554 {
555 	struct net_device *ndev = platform_get_drvdata(pdev);
556 
557 	unregister_netdev(ndev);
558 	free_irq(ndev->irq, ndev);
559 	moxart_mac_free_memory(ndev);
560 	free_netdev(ndev);
561 
562 	return 0;
563 }
564 
565 static const struct of_device_id moxart_mac_match[] = {
566 	{ .compatible = "moxa,moxart-mac" },
567 	{ }
568 };
569 MODULE_DEVICE_TABLE(of, moxart_mac_match);
570 
571 static struct platform_driver moxart_mac_driver = {
572 	.probe	= moxart_mac_probe,
573 	.remove	= moxart_remove,
574 	.driver	= {
575 		.name		= "moxart-ethernet",
576 		.of_match_table	= moxart_mac_match,
577 	},
578 };
579 module_platform_driver(moxart_mac_driver);
580 
581 MODULE_DESCRIPTION("MOXART RTL8201CP Ethernet driver");
582 MODULE_LICENSE("GPL v2");
583 MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
584