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