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 #include <linux/circ_buf.h>
29 
30 #include "moxart_ether.h"
31 
32 static inline void moxart_desc_write(u32 data, u32 *desc)
33 {
34 	*desc = cpu_to_le32(data);
35 }
36 
37 static inline u32 moxart_desc_read(u32 *desc)
38 {
39 	return le32_to_cpu(*desc);
40 }
41 
42 static inline void moxart_emac_write(struct net_device *ndev,
43 				     unsigned int reg, unsigned long value)
44 {
45 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
46 
47 	writel(value, priv->base + reg);
48 }
49 
50 static void moxart_update_mac_address(struct net_device *ndev)
51 {
52 	moxart_emac_write(ndev, REG_MAC_MS_ADDRESS,
53 			  ((ndev->dev_addr[0] << 8) | (ndev->dev_addr[1])));
54 	moxart_emac_write(ndev, REG_MAC_MS_ADDRESS + 4,
55 			  ((ndev->dev_addr[2] << 24) |
56 			   (ndev->dev_addr[3] << 16) |
57 			   (ndev->dev_addr[4] << 8) |
58 			   (ndev->dev_addr[5])));
59 }
60 
61 static int moxart_set_mac_address(struct net_device *ndev, void *addr)
62 {
63 	struct sockaddr *address = addr;
64 
65 	eth_hw_addr_set(ndev, address->sa_data);
66 	moxart_update_mac_address(ndev);
67 
68 	return 0;
69 }
70 
71 static void moxart_mac_free_memory(struct net_device *ndev)
72 {
73 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
74 	int i;
75 
76 	for (i = 0; i < RX_DESC_NUM; i++)
77 		dma_unmap_single(&priv->pdev->dev, priv->rx_mapping[i],
78 				 priv->rx_buf_size, DMA_FROM_DEVICE);
79 
80 	if (priv->tx_desc_base)
81 		dma_free_coherent(&priv->pdev->dev,
82 				  TX_REG_DESC_SIZE * TX_DESC_NUM,
83 				  priv->tx_desc_base, priv->tx_base);
84 
85 	if (priv->rx_desc_base)
86 		dma_free_coherent(&priv->pdev->dev,
87 				  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(&priv->pdev->dev,
148 						     priv->rx_buf[i],
149 						     priv->rx_buf_size,
150 						     DMA_FROM_DEVICE);
151 		if (dma_mapping_error(&priv->pdev->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 descriptor 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 	napi_enable(&priv->napi);
173 
174 	moxart_mac_reset(ndev);
175 	moxart_update_mac_address(ndev);
176 	moxart_mac_setup_desc_ring(ndev);
177 	moxart_mac_enable(ndev);
178 	netif_start_queue(ndev);
179 
180 	netdev_dbg(ndev, "%s: IMR=0x%x, MACCR=0x%x\n",
181 		   __func__, readl(priv->base + REG_INTERRUPT_MASK),
182 		   readl(priv->base + REG_MAC_CTRL));
183 
184 	return 0;
185 }
186 
187 static int moxart_mac_stop(struct net_device *ndev)
188 {
189 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
190 
191 	napi_disable(&priv->napi);
192 
193 	netif_stop_queue(ndev);
194 
195 	/* disable all interrupts */
196 	writel(0, priv->base + REG_INTERRUPT_MASK);
197 
198 	/* disable all functions */
199 	writel(0, priv->base + REG_MAC_CTRL);
200 
201 	return 0;
202 }
203 
204 static int moxart_rx_poll(struct napi_struct *napi, int budget)
205 {
206 	struct moxart_mac_priv_t *priv = container_of(napi,
207 						      struct moxart_mac_priv_t,
208 						      napi);
209 	struct net_device *ndev = priv->ndev;
210 	struct sk_buff *skb;
211 	void *desc;
212 	unsigned int desc0, len;
213 	int rx_head = priv->rx_head;
214 	int rx = 0;
215 
216 	while (rx < budget) {
217 		desc = priv->rx_desc_base + (RX_REG_DESC_SIZE * rx_head);
218 		desc0 = moxart_desc_read(desc + RX_REG_OFFSET_DESC0);
219 		rmb(); /* ensure desc0 is up to date */
220 
221 		if (desc0 & RX_DESC0_DMA_OWN)
222 			break;
223 
224 		if (desc0 & (RX_DESC0_ERR | RX_DESC0_CRC_ERR | RX_DESC0_FTL |
225 			     RX_DESC0_RUNT | RX_DESC0_ODD_NB)) {
226 			net_dbg_ratelimited("packet error\n");
227 			ndev->stats.rx_dropped++;
228 			ndev->stats.rx_errors++;
229 			goto rx_next;
230 		}
231 
232 		len = desc0 & RX_DESC0_FRAME_LEN_MASK;
233 
234 		if (len > RX_BUF_SIZE)
235 			len = RX_BUF_SIZE;
236 
237 		dma_sync_single_for_cpu(&priv->pdev->dev,
238 					priv->rx_mapping[rx_head],
239 					priv->rx_buf_size, DMA_FROM_DEVICE);
240 		skb = netdev_alloc_skb_ip_align(ndev, len);
241 
242 		if (unlikely(!skb)) {
243 			net_dbg_ratelimited("netdev_alloc_skb_ip_align failed\n");
244 			ndev->stats.rx_dropped++;
245 			ndev->stats.rx_errors++;
246 			goto rx_next;
247 		}
248 
249 		memcpy(skb->data, priv->rx_buf[rx_head], len);
250 		skb_put(skb, len);
251 		skb->protocol = eth_type_trans(skb, ndev);
252 		napi_gro_receive(&priv->napi, skb);
253 		rx++;
254 
255 		ndev->stats.rx_packets++;
256 		ndev->stats.rx_bytes += len;
257 		if (desc0 & RX_DESC0_MULTICAST)
258 			ndev->stats.multicast++;
259 
260 rx_next:
261 		wmb(); /* prevent setting ownership back too early */
262 		moxart_desc_write(RX_DESC0_DMA_OWN, desc + RX_REG_OFFSET_DESC0);
263 
264 		rx_head = RX_NEXT(rx_head);
265 		priv->rx_head = rx_head;
266 	}
267 
268 	if (rx < budget)
269 		napi_complete_done(napi, rx);
270 
271 	priv->reg_imr |= RPKT_FINISH_M;
272 	writel(priv->reg_imr, priv->base + REG_INTERRUPT_MASK);
273 
274 	return rx;
275 }
276 
277 static int moxart_tx_queue_space(struct net_device *ndev)
278 {
279 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
280 
281 	return CIRC_SPACE(priv->tx_head, priv->tx_tail, TX_DESC_NUM);
282 }
283 
284 static void moxart_tx_finished(struct net_device *ndev)
285 {
286 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
287 	unsigned int tx_head = priv->tx_head;
288 	unsigned int tx_tail = priv->tx_tail;
289 
290 	while (tx_tail != tx_head) {
291 		dma_unmap_single(&priv->pdev->dev, priv->tx_mapping[tx_tail],
292 				 priv->tx_len[tx_tail], DMA_TO_DEVICE);
293 
294 		ndev->stats.tx_packets++;
295 		ndev->stats.tx_bytes += priv->tx_skb[tx_tail]->len;
296 
297 		dev_consume_skb_irq(priv->tx_skb[tx_tail]);
298 		priv->tx_skb[tx_tail] = NULL;
299 
300 		tx_tail = TX_NEXT(tx_tail);
301 	}
302 	priv->tx_tail = tx_tail;
303 	if (netif_queue_stopped(ndev) &&
304 	    moxart_tx_queue_space(ndev) >= TX_WAKE_THRESHOLD)
305 		netif_wake_queue(ndev);
306 }
307 
308 static irqreturn_t moxart_mac_interrupt(int irq, void *dev_id)
309 {
310 	struct net_device *ndev = (struct net_device *)dev_id;
311 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
312 	unsigned int ists = readl(priv->base + REG_INTERRUPT_STATUS);
313 
314 	if (ists & XPKT_OK_INT_STS)
315 		moxart_tx_finished(ndev);
316 
317 	if (ists & RPKT_FINISH) {
318 		if (napi_schedule_prep(&priv->napi)) {
319 			priv->reg_imr &= ~RPKT_FINISH_M;
320 			writel(priv->reg_imr, priv->base + REG_INTERRUPT_MASK);
321 			__napi_schedule(&priv->napi);
322 		}
323 	}
324 
325 	return IRQ_HANDLED;
326 }
327 
328 static netdev_tx_t moxart_mac_start_xmit(struct sk_buff *skb,
329 					 struct net_device *ndev)
330 {
331 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
332 	void *desc;
333 	unsigned int len;
334 	unsigned int tx_head;
335 	u32 txdes1;
336 	netdev_tx_t ret = NETDEV_TX_BUSY;
337 
338 	spin_lock_irq(&priv->txlock);
339 
340 	tx_head = priv->tx_head;
341 	desc = priv->tx_desc_base + (TX_REG_DESC_SIZE * tx_head);
342 
343 	if (moxart_tx_queue_space(ndev) == 1)
344 		netif_stop_queue(ndev);
345 
346 	if (moxart_desc_read(desc + TX_REG_OFFSET_DESC0) & TX_DESC0_DMA_OWN) {
347 		net_dbg_ratelimited("no TX space for packet\n");
348 		ndev->stats.tx_dropped++;
349 		goto out_unlock;
350 	}
351 	rmb(); /* ensure data is only read that had TX_DESC0_DMA_OWN cleared */
352 
353 	len = skb->len > TX_BUF_SIZE ? TX_BUF_SIZE : skb->len;
354 
355 	priv->tx_mapping[tx_head] = dma_map_single(&priv->pdev->dev, skb->data,
356 						   len, DMA_TO_DEVICE);
357 	if (dma_mapping_error(&priv->pdev->dev, priv->tx_mapping[tx_head])) {
358 		netdev_err(ndev, "DMA mapping error\n");
359 		goto out_unlock;
360 	}
361 
362 	priv->tx_len[tx_head] = len;
363 	priv->tx_skb[tx_head] = skb;
364 
365 	moxart_desc_write(priv->tx_mapping[tx_head],
366 	       desc + TX_REG_OFFSET_DESC2 + TX_DESC2_ADDRESS_PHYS);
367 	moxart_desc_write((uintptr_t)skb->data,
368 	       desc + TX_REG_OFFSET_DESC2 + TX_DESC2_ADDRESS_VIRT);
369 
370 	if (skb->len < ETH_ZLEN) {
371 		memset(&skb->data[skb->len],
372 		       0, ETH_ZLEN - skb->len);
373 		len = ETH_ZLEN;
374 	}
375 
376 	dma_sync_single_for_device(&priv->pdev->dev, priv->tx_mapping[tx_head],
377 				   priv->tx_buf_size, DMA_TO_DEVICE);
378 
379 	txdes1 = TX_DESC1_LTS | TX_DESC1_FTS | (len & TX_DESC1_BUF_SIZE_MASK);
380 	if (tx_head == TX_DESC_NUM_MASK)
381 		txdes1 |= TX_DESC1_END;
382 	moxart_desc_write(txdes1, desc + TX_REG_OFFSET_DESC1);
383 	wmb(); /* flush descriptor before transferring ownership */
384 	moxart_desc_write(TX_DESC0_DMA_OWN, desc + TX_REG_OFFSET_DESC0);
385 
386 	/* start to send packet */
387 	writel(0xffffffff, priv->base + REG_TX_POLL_DEMAND);
388 
389 	priv->tx_head = TX_NEXT(tx_head);
390 
391 	netif_trans_update(ndev);
392 	ret = NETDEV_TX_OK;
393 out_unlock:
394 	spin_unlock_irq(&priv->txlock);
395 
396 	return ret;
397 }
398 
399 static void moxart_mac_setmulticast(struct net_device *ndev)
400 {
401 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
402 	struct netdev_hw_addr *ha;
403 	int crc_val;
404 
405 	netdev_for_each_mc_addr(ha, ndev) {
406 		crc_val = crc32_le(~0, ha->addr, ETH_ALEN);
407 		crc_val = (crc_val >> 26) & 0x3f;
408 		if (crc_val >= 32) {
409 			writel(readl(priv->base + REG_MCAST_HASH_TABLE1) |
410 			       (1UL << (crc_val - 32)),
411 			       priv->base + REG_MCAST_HASH_TABLE1);
412 		} else {
413 			writel(readl(priv->base + REG_MCAST_HASH_TABLE0) |
414 			       (1UL << crc_val),
415 			       priv->base + REG_MCAST_HASH_TABLE0);
416 		}
417 	}
418 }
419 
420 static void moxart_mac_set_rx_mode(struct net_device *ndev)
421 {
422 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
423 
424 	spin_lock_irq(&priv->txlock);
425 
426 	(ndev->flags & IFF_PROMISC) ? (priv->reg_maccr |= RCV_ALL) :
427 				      (priv->reg_maccr &= ~RCV_ALL);
428 
429 	(ndev->flags & IFF_ALLMULTI) ? (priv->reg_maccr |= RX_MULTIPKT) :
430 				       (priv->reg_maccr &= ~RX_MULTIPKT);
431 
432 	if ((ndev->flags & IFF_MULTICAST) && netdev_mc_count(ndev)) {
433 		priv->reg_maccr |= HT_MULTI_EN;
434 		moxart_mac_setmulticast(ndev);
435 	} else {
436 		priv->reg_maccr &= ~HT_MULTI_EN;
437 	}
438 
439 	writel(priv->reg_maccr, priv->base + REG_MAC_CTRL);
440 
441 	spin_unlock_irq(&priv->txlock);
442 }
443 
444 static const struct net_device_ops moxart_netdev_ops = {
445 	.ndo_open		= moxart_mac_open,
446 	.ndo_stop		= moxart_mac_stop,
447 	.ndo_start_xmit		= moxart_mac_start_xmit,
448 	.ndo_set_rx_mode	= moxart_mac_set_rx_mode,
449 	.ndo_set_mac_address	= moxart_set_mac_address,
450 	.ndo_validate_addr	= eth_validate_addr,
451 };
452 
453 static int moxart_mac_probe(struct platform_device *pdev)
454 {
455 	struct device *p_dev = &pdev->dev;
456 	struct device_node *node = p_dev->of_node;
457 	struct net_device *ndev;
458 	struct moxart_mac_priv_t *priv;
459 	struct resource *res;
460 	unsigned int irq;
461 	int ret;
462 
463 	ndev = alloc_etherdev(sizeof(struct moxart_mac_priv_t));
464 	if (!ndev)
465 		return -ENOMEM;
466 
467 	irq = irq_of_parse_and_map(node, 0);
468 	if (irq <= 0) {
469 		netdev_err(ndev, "irq_of_parse_and_map failed\n");
470 		ret = -EINVAL;
471 		goto irq_map_fail;
472 	}
473 
474 	priv = netdev_priv(ndev);
475 	priv->ndev = ndev;
476 	priv->pdev = pdev;
477 
478 	priv->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
479 	if (IS_ERR(priv->base)) {
480 		ret = PTR_ERR(priv->base);
481 		goto init_fail;
482 	}
483 	ndev->base_addr = res->start;
484 
485 	ret = platform_get_ethdev_address(p_dev, ndev);
486 	if (ret == -EPROBE_DEFER)
487 		goto init_fail;
488 	if (ret)
489 		eth_hw_addr_random(ndev);
490 	moxart_update_mac_address(ndev);
491 
492 	spin_lock_init(&priv->txlock);
493 
494 	priv->tx_buf_size = TX_BUF_SIZE;
495 	priv->rx_buf_size = RX_BUF_SIZE;
496 
497 	priv->tx_desc_base = dma_alloc_coherent(p_dev, TX_REG_DESC_SIZE *
498 						TX_DESC_NUM, &priv->tx_base,
499 						GFP_DMA | GFP_KERNEL);
500 	if (!priv->tx_desc_base) {
501 		ret = -ENOMEM;
502 		goto init_fail;
503 	}
504 
505 	priv->rx_desc_base = dma_alloc_coherent(p_dev, RX_REG_DESC_SIZE *
506 						RX_DESC_NUM, &priv->rx_base,
507 						GFP_DMA | GFP_KERNEL);
508 	if (!priv->rx_desc_base) {
509 		ret = -ENOMEM;
510 		goto init_fail;
511 	}
512 
513 	priv->tx_buf_base = kmalloc_array(priv->tx_buf_size, TX_DESC_NUM,
514 					  GFP_KERNEL);
515 	if (!priv->tx_buf_base) {
516 		ret = -ENOMEM;
517 		goto init_fail;
518 	}
519 
520 	priv->rx_buf_base = kmalloc_array(priv->rx_buf_size, RX_DESC_NUM,
521 					  GFP_KERNEL);
522 	if (!priv->rx_buf_base) {
523 		ret = -ENOMEM;
524 		goto init_fail;
525 	}
526 
527 	platform_set_drvdata(pdev, ndev);
528 
529 	ret = devm_request_irq(p_dev, irq, moxart_mac_interrupt, 0,
530 			       pdev->name, ndev);
531 	if (ret) {
532 		netdev_err(ndev, "devm_request_irq failed\n");
533 		goto init_fail;
534 	}
535 
536 	ndev->netdev_ops = &moxart_netdev_ops;
537 	netif_napi_add_weight(ndev, &priv->napi, moxart_rx_poll, RX_DESC_NUM);
538 	ndev->priv_flags |= IFF_UNICAST_FLT;
539 	ndev->irq = irq;
540 
541 	SET_NETDEV_DEV(ndev, &pdev->dev);
542 
543 	ret = register_netdev(ndev);
544 	if (ret)
545 		goto init_fail;
546 
547 	netdev_dbg(ndev, "%s: IRQ=%d address=%pM\n",
548 		   __func__, ndev->irq, ndev->dev_addr);
549 
550 	return 0;
551 
552 init_fail:
553 	netdev_err(ndev, "init failed\n");
554 	moxart_mac_free_memory(ndev);
555 irq_map_fail:
556 	free_netdev(ndev);
557 	return ret;
558 }
559 
560 static int moxart_remove(struct platform_device *pdev)
561 {
562 	struct net_device *ndev = platform_get_drvdata(pdev);
563 
564 	unregister_netdev(ndev);
565 	devm_free_irq(&pdev->dev, ndev->irq, ndev);
566 	moxart_mac_free_memory(ndev);
567 	free_netdev(ndev);
568 
569 	return 0;
570 }
571 
572 static const struct of_device_id moxart_mac_match[] = {
573 	{ .compatible = "moxa,moxart-mac" },
574 	{ }
575 };
576 MODULE_DEVICE_TABLE(of, moxart_mac_match);
577 
578 static struct platform_driver moxart_mac_driver = {
579 	.probe	= moxart_mac_probe,
580 	.remove	= moxart_remove,
581 	.driver	= {
582 		.name		= "moxart-ethernet",
583 		.of_match_table	= moxart_mac_match,
584 	},
585 };
586 module_platform_driver(moxart_mac_driver);
587 
588 MODULE_DESCRIPTION("MOXART RTL8201CP Ethernet driver");
589 MODULE_LICENSE("GPL v2");
590 MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
591